GB2509691A - Rope gripping device having a cam and base grip mounted in a module that is removably engaged in a housing - Google Patents

Abstract

A rope gripping device 10 comprises a housing 12 for attachment to a surface, preferably a deck, and able to receive a rope 24 extending therethrough, a module unit 20 removably engagable with the housing 12, an eccentric cam 38 having a first gripping surface 36 defined on its perimeter, and rotatably coupled to the module unit 20, a base grip 30 depending from the module unit 20 and supporting a second gripping surface 26 in an opposed configuration to the first gripping surface 36 to define a space for receiving the rope 24, and a spring acting on the cam 38 to rotation the cam to bring the gripping surfaces closer together. The cam 38 and the base grip 30 are received within the housing 12 when the module unit 20 is engaged with the housing 12, and removed from the housing 12 when the module unit 20 is disengaged from the housing.

Description

TETLE OF THE INVENTION

MODULAR ROPE-GRlPPNG DEVICE

S

BACKGROUND OF THE INVENTION

The present invention relates to a device for holding or gripping a rope or simflar flexible elongate tern.

Devices for securing ropes are used extensively on sailing boats. It is important that a]oadbearing rope is gripped tightly when it needs to be secured, and also that the rope can be released promptly when required. High performance and reliability are demanded from these devices, since both safety and sailing ability can depend on them, Improvements in rope gripping devices are necessary to achieve optimum performance in conjunction with developments in ropes and sails. Also, servicing and maintenance of the devices are vital for continued good operation.

Two types of devices commonly employed for gripping ropes are those based on a pair of sliding jaws, and those based on a rotating cam. In both cases, a pair of opposed surfaces for gripping the rope are contained in an outer housing that is fastened to the deck or some other surface of the boat. A handle, latch or similar structure is provided for engaging/disengaging the grip. in a jaw-based device, the rope passes between two opposed elongate jaws that each have a gripping surface extending lengthwise along the rope. The jaws slide forwards and backwards, via a bearing or the like, to move the gripping surfaces closer together to grip the rope or further apart to release it. The pair of jaws may be configured as a single unit that can be removed from the housing for maintenance. Examples of jaw-based devices are the ZR Jammer, the ZS Jammer and the XX Powerciutch, all made by Spinlock Limited (lsle of Wight, United Kingdom).

In a cam-based device, a fixed lower gripping surface is positioned integrally within the housing, and a cam having an upper gripping surface defined on part of its perimeter is arranged to be rotatable such that the upper gripping surface can be moved towards and away from the lower gripping surface to grip or release a rope passing between the two surfaces. For servicing, the entire device is dismantled, including removal of the cam from the housing. ER 0,117,466 gives an example of a cam-based device.

There are various advantages and drawbacks to the two types of device. A cam design has fewer moving parts, leading to a simpler construction and a tower cost, and can accommodate a wider range of rope diameters for a given length of device. Overall, the device can be shorter than for a jaw-based design because the section of rope being grIpped remains in the same place within the device, rather than moving forward during gripping by sliding jaws. For such reasons, users may prefer a cam device. However, there are disadvantages compared to a jaw device, such as a shorter, smaller grip surface area plus relative movement between rope and grip surface, which give increased rope wear and reduced load capacity. Also, the fixed lower gripping surface in a cam design reduces the efficiency of the gripping action and further increases rope wear. Hence, there is scope for improvement in cain-based devices.

A further alternative design is described in EP 0,179,302 and EP 0,424,307. In these examples, a pair of rope engaging surfaces are always maintained parallel to one another during gripping and release by being swingably connected to the side walls of the device frame via pivoted linking arms such that the pivot connections form a parallelogram.

Rope holding devices should be kept clean to maintain optimum gripping performance. The cleaning Is an ongoing job, as grit and other debris can easily find its way inside the housing, particularly when carried inside with the rope. Also, ropes often have a surface lubricant or coating that can clog the gripping surfaces. An impediment to cleaning, servicing and repair is that the housing of the device will often be bolted onto a part of the boat such as a cabin roof, with bolts extending ight through the surface to be secured with nuts on the opposite side. For safety and improved appearance, the protruding bolts are boxed In or otherwise covered. To achieve complete removal of a device, it is therefore necessary to remove the covering over the bolts before the bolts can be unfastened. For cam-based devices, this has to be done even for thorough cleaning, owing to the integral nature of the lower gripping surface within the housing; the entire device needs to be dismantled for proper cleaning and servicing. This can make maintenance an unattractive and therefore neglected or incomplete task, leading to comprised safety and sailing performance.

Until recently, ropes tended to have a substantial diameter, and were made from polyester gMng a soft structure with some stretch. Ropes of this sort are easy to grip securely, so that devices with a fixed lower gripping stifaces and a cam can provide an adequate hold. However, changes in rope design using new materials mean that more modem ropes are both thinner and stiffer (low stretch). This gives a reduced area by which to grip the rope, so that a given cam-based device is not able to provide the same level of grip as with an older rope. Also, other parts such as the sails are also stiffer, which puts additional demand on the device as there is still less stretch in the system overall. The newer rope matedals also produce a more slippery rope, further increasing the difficulty of gripping. Hence, there is a requirement for improved cam-based rope-gripping devices to provide better rope holding performance under modem conditions. jl

SUMFMRY OF THE INVENTiON Accordingly, the present invention is directed to a rope-gripping device comprising: a housing configured to receive a rope extending therethrough; a module s unit removabiy engagable with the housing; an eccentric cam having a first gripping surface defined on its perimeter, and rotatably mounted on the module unit for rotation about an axis perpendicular to the extent of a received rope; a base grip depending from the module unit and supporting a second gripping surface in an opposed configuration to the first gripping surface such that the first and second gripping surfaces define a space therebetween for receiving the rope for gripping; and a spring acting on the cam to bias rotation of the cam in a direction that brings the first gripping surface closer to the second gripping surface to decrease the space therebetween and grip the received rope; wherein the cam and the base grip are received within the housing when the module unit is engaged with the housing, arid removed from the housing when the module unit is disengaged from the housing.

The modular construction aVows both of the gripping surfaces to be easily removed from the housing. This facilitates cleaning, servicing and parts replacement so that the device may readily be maintained in optimum condition. The gripping surfaces can both be accessed by the simple disengagement of a module comprised of the module body, cam and base grip from the housing without any need to unfasten the entire device from the deck or other surface to which it is attached. This simple and quick access promotes regular maintenance, and hence improves safety and performance.

In some embodiments, the module unit has side walls that align with and extend side walls of the housing when the module unit is engaged with the housing. This can give a smooth regular external surface to the device, which eliminates edges and corners upon which a rope may undesirably snag.

The device may further comprise a fastener to fasten the module unit to the housing when the module unit is engaged with the housing. For example, the housing and the module unit may have cooperating bores that are aligned when the module unit is engaged with the housing, and the fastener may comprise a screw engagable in the bores. Other means of fastening or locking the module unit in place against the housing may alternatively be employed, however, and are not precluded from the invention.

On some embodiments, the device may further comprise a handle pivotably mounted at one end to the housing and coupled to one or both of the cam and the base grip such that turning of the handle acts to move one or both of the cam and the base grip to increase the spacing between the first gripping surface and the second gripping surface and re!ease a gripped rope. The handle may be pivotably mounted on the housing for turning about an axis parallel to the axis of rotation of the cam.

For example, the handle may be tunable between a closed position folded against the housing and a release position in which the spacing between the first s gripping surface and the second gripping surface is Increased, and In which the module unit when engaged with the housing lies between the housing and the handle in its closed position. This enhances safety, because the handle can be folded to lie over the module unit in its closed position whenever a rope is being gripped by the device. No attempt can be made to remove the module unit from the housing without turning the handle towards or into the release position.

In some embodiments, the base grip may depend from the module unit by a mounting that allows rotation of the base grip relative to the module unit about an axis parallel to the axis of rotation of the cam, rotation of the base grip causing movement of the second gripping surface towards and away from the first gripping surface. This movement enables the second gripping surface to cooperate with the first gripping surface in dosing onto a rope to grip it, thereby sharing the load between the two gripping surfaces and enhancing the grip.

Any rotation of the base grip arranged to move the second gripping surface may be employed. However, an advantageous arrangement Is one in which the first gripping surface and the second gripping surface are moved towards each other and away from each other to decrease and increase the spacing therebetween by rotation of the cam and rotation of the base grip in the same direction.

For such rotatable mounting of the base grip, the mounting of the base grip may comprise a base grip axle on which the base grip is mounted, the axle supported on the module unit.

The cam may be mounted on the module unit by a cam axle on which the cam is mounted, the cam axle supported on the module unit.

In alternative embodiments, the base grip may depend rigidly from the module unit In such configurations, gripping of the rope is provided by movement of the cam alone.

BRIEF DESCRPTON OF THE DRAWINGS

For a better undersianthng of the invention and to show how the same may be carried into effect reference is now made by way of exampre to the accompanying drawings in which: Figure 1 shows a perspective cut-away view of a rope-gripping device according to the phor ad; Figure 2 shows a side view, partially cut away, of a rope-gripping device according to an embodiment of the nvention; Figure 3A to 3E show a series of views depicting movement of components of the device of Figure 2 during the gripping of a rope; Figures 4A to 4B show a series of views depicting movement of the components shown in Figures 3A to 3E during release of a gripped rope; Figure 5 shows an externa perspective view of the rope-gripping device of Figure 2; and Figure 6 shows an externaD perspective view of the rope-gripping device of Figure 2 after separation of a moduar part from the housing.

DETAILEQDESCRIPTION

Figure 1 shows a partiaDy cutaway perspective view of a cam-based rope gripping device according to the prior art, such as the XIS clutch made by Spinlock Limited (Isle of Wight, United Kingdom). Rope-gripping devices are designed to automatically grip a loaded rope pulled through a pair of gripping surfaces, and have a handle-operated function to release a gripped loaded rope. Loads up to 1000 kg can commonly be held by a cam-based rope-gripping device.

The device 100 comprises a housing 102 which is shown cut away in the Figure.

The housing has four walls (two side walls and two ends walls), and a bottom surface 104 which is, in a marine application, fastened to the deck, mast or simfiar surface of a boat by bolts or screws pas&ng through the surface. Inside the housing is provided a pair of rope gripping surfaces. The lower gripping surface 106 is an upwardly facing ridged or toothed portion formed on the top of a plate 108 that is fixed within the bottom is of the housing 102. A pair of eyelets 110 are disposed one in each end wall of the housing 102. A rope 112 to be gripped by the device 100 is fed through a first eyelet 110, over the lower gripping surface 106 and out through the other eye!et 110. The eyelets align the rope for effective gripping and allow the rope 112 to run smoothly through the device when not gripped.

A cam 114 is mounted inside the housing 102, for pivoting about an axle 116 that is mounted between two supporting uprights (not shown) attached to the plate 108. The eccentric rotation of the cam is springioaded by a spring 118 passing around the axle, and secured against one or more pins 120 The outer perimeter of the cam 114 faces generally downwardly and is ridged or toothed so as to form an upper gripping surface 120 opposed to the lower gripping surface 106. The rope 112 passes between the two gripping surfaces 106, 120. Rotation of the cam 114 in an anti-clockwise direction (as viewed in Figure 1, shown by the curved arrow) about the axle 116, under the force of the spring 118, brings the upper gripping surface 120 closer to the lower gripping surface 106, owing to the increasing radius of the cam 114. This increased proximity of the gripping surfaces 106, 120 compresses and hence grips the rope 112.

The device 100 has a handle 122 that folds over the top of the housing 102 in a closed, substantially horizontal position. The handle 122 is pivoted at one end about a second axle 174 extending across the housing 102 from one side wall to the other at one end of the housing 102, via an eccentrically shaped portion 126. When the handle 122 is opened by rotating it about the axle 124 to reach a substantially vertical position, the eccentrically shaped portion 126 also rotates and comes into contact with a bar 128 on the cam 114. Further rotation of the handle 122 pushes against the bar 128 and causes a translation of the cam axle 118 and hence also of the cam 114 away from the lower gripping surface 106. This moves the upper gripping surface 120 away from the lower gripping surface 106, to release the rope 112 once the space between the gripping surfaces 106, 120 is sufficiently widened. Folding of the handle 122 hack down into its closed position restores the cam 114 to the loading of the spring 118, which biases the upper gripping surface 120 towards the lower gripping surface 106.

This configuration of a pair of gripping surfaces provided by a sprung cam and a fixed base plate resus in a reduced mechanical advantage of the cam as the rcpe engages with the ridges or teeth on the base plate. An adequate grip can be achieved on relatively soft polyester ropes, but the grip is reduced for more modern ropes that have low stretch.

For servicing and cleaning, the cam can be removed from the housing when the handle is open, thereby exposing both gripping surfaces, However, the lower gripping surface on the fixed plate at the base of the housing remains in place unless the entire device is detached from its mounting surface by unfastening the bolts or screws that hold it in place.

Figure 2 shows a partially cutaway side view of a rope-gripping device according to an embodiment of the present invention.

The device 10 has a housing 12 Forming a pair of opposite side walls, a pair of opposite end walls and a base 14. n this embodiment, the base is formed with apertures (not shown) to allow fastening of the device 10 to a surface such as a deck by means of bolts, screws or the like. The top of the housing 12 is open to receive a module unit 20 discussed further below, and is also covered by a handle 16. In the position illustrated in Figure 2, the handle 16 folds down over the top of the housing 12 in a closed substantially horizontal position, and is connected at one end to the housing by a handle axle 18. The handle axle 18 runs through the housing from one side wall to the other side wall, at one end of the housing 12 towards the top. The handle 16 can be opened by turning it about the handle axle 18 towards, through and beyond a substantially vertical position, the rotation being about an axis substantially orthogonal to the length of a rope 24 extending through the housing.

The device 10 also comprises a module unit 20. The module unit 20 is removably engagable with the housing 12, such that t can be engaged with the housing 12 into a locked or fastened position so as to form part of the housing 12, or disengaged from the housing 12 and removed therefrom. In this example, the module unit 20 is shaped to have two opposite side walls and two opposite end walls, so that when the module unit is engaged with the housing 12, its side waDs and one end wal ahgn with and form extensions to the side walls and end wall of the housing 12. En this way, a smooth or regular outer surface for the device 10 is formed. lii this example, the module unit 20 is fastened into the engaged position by a screw 22 passing through a bore 23a in the end wall of the module unit 20 and into a cooperating threaded bore 23b formed in the housing 12. Other fastening or locking arrangements may be used however, such as one or more screws passing through the side walls, or a resihent latch on the module unit 20 configured to hook over a protrusion or into a recess on the housing 12. In any case, preferably the fastening arrangement holds the module unit 20 secur&y in place against or within the housing 12 while also being simple and quick to disengage without the need for specialised tools.

In Figure 2, the housing 12 is shown with part of the side wall cut away to reveal the interior components of the device 10 housed within the housing 12. The housing 12 has an aperture or opening (not shown) in each end wall to allow the rope 24 to pass through the housing 12 along its length. The apertures are aligned so that rope 24 remains straight.

The device 10 grips the rope 24 inside the housing, between two gripping surfaces. A lower gripping surface 26 is defined by a series of teeth, ridges, corrugations or other surface roughenings formed on the upper surface of a substantially horizontal plate 28 that is the bottom face of a base grip 30, The base grip 30 is substantially U-shaped in cross-section (squared or curved at the corners), formed by the plate 28 at the bottom, and two parallel de walls 32 extending upwardly from the edges of the plate 28. The side walls 32 are parallel with the side walls of the housing 12, the base grip 30 being sized to fit within the housing 12 with freedom of movement. Towards the top parts of the side walls 32, the base grip 30 is suspended from the module unit 20. In this example, the base grip 30 is coupled to the module unit 20 by way of a base grip axle 34 that passes through holes in the side walls 32 of the base grip 30 and extends into or through the side walls of the module unit 20, where it is held in place. The side waDs 32 of the base grip 30 lie inside the side walls of the module unit 20, and the base grip 30 is free to swing on its axle with respect to the module unit 20. Rotation of the base grip is about an axis substantially orthogonal to the extent of the rope 24 as it passes through the housing 12.

An upper, gripping surface 36 is defined by a second series of teeth, ridges, corrugations or other surface roughenings formed on the outer perimeter surface of an eccentric cam 38. The cam 38 is positioned with respect to the base grip 30 such that the upper and lower gripping surfaces 26, 36 are opposed and define a space -i 0 therebetween for the rope 24 to pass through as it extends through the housing I 2 The cam 38 is supported on a earn ax 40 that passes through a hole in the cam 38 and into or through the side waHs of the module unit 20. The cam 38 can rotate about its axle 40, with the axis of rotation being substantially parallel to the axis of rotation of the base grip 30. The cam 38 hangs from its axle 40 to lie partly between the side walls 32 of the base grip 30. Both the cam 38 and the base grip 30 are coupled to the module unit 20, and not directly to the hou&ng 12.

Also, the cam 38 arid the base ghp 30 are coupled to each other. The cam 38 has a pin 42 protruding from its side face, in this example at a lower part of the side face near the perimeter. The base ghp 30 has a slot 44 in its side wall 32. These structures may be provided on one or both sides of the cam 38 and the base grip 30. The slot 44 is shaped in two portions. An upper portion 44a is arcuate, and arranged at a constant radius from the cam axle 40. A lower portion 44b, which is connected to the upper portion 44a to form a continuous slot, is straight and extends away from the cam axle 40.

Thus, a first end of the slot 44 where the arcuate portion 44a begins is closer to the cam axle 40 than a second end of the slot 44 where the straight or linear portion 44b finishes.

The first end is nearest to the base grip axle 34 and the second end is nearest to the plate 28.

The cam 38 is biased or spring-loaded by a spring (not shown) that biasses the cam 38 in a direction of clockwise rotation (as viewed in Figure 2). The eccentric radius of the cam 38 is such that increased clockwise rotation brings the upper gripping surface 36 into increased proximity wfth the lower gripping surface 26. The space beeen the two gripping surfaces is hence reduced, and the rope 24 between the two gripping surfaces is compressed, gripped and held. During this rotation, the pin 42 moves along the arcuate portion 44a of the slot 44, and the base grip 30 and hence the lower gripping surface 26 remain wholly or largely stationary. Thus far, the gripping action is substantially the same as that of prior art cam-based devices such as that of Figure 1, in which the lower gripping surface is fixed and remains motionless during gripping.

However, in the device of Figure 2, the gripping is enhanced. When the rotation of the cam 38 brings the pin 42 to the junction of the arcuate portion 44a with the linear portion 44b of the slot 44, the pin 42 enters the linear slot portion 44h (the position shown in Figure 2), and further turning of the cam 38 moves the pin 42 along the slot 44 towards its second end which pulls the base grip 30 around with the cam 38, the base grip 30 rotating about its axle 34. This action tips the lower gripping surface 26 upwards, bringing it closer to the upper gripping surface 36, and hence reducing the spacing and increasing the grip on the rope 24. This continues until the pin 42 reaches the second end of the &ot 44, at the bottom of the knear slot portion 44b. The shape and length of the slot can be selected to provide the precise required amount of relative movement between the cam 38 and the base grip 30, thereby aflowing tailoring of the gripping action.

Thus, there is a dynamic reaction between the cam 38 and the base grip 30; these components move together, with the motion of the base grip 30 being induced by the motion of the cam 38. The rate of closure of the two gripping surfaces 26, 36 -that is, the speed at which the two gripping surfaces approach each other is increased by the movement of the lower gripping surface 26 produced by movement of the base grip Ic 30 as it is pufled by the cam 38. Thus, the rope 24 is gripped more quickly. Also, the load is shared between the two gripping surfaces 26, 36, making possible a stronger hold on the rope 24 than can be achieved by the same cam size and upper gripping surface working on a fixed lower gripping surface. This dynamic reactive gripping or clutching offers an improved rope gripping mechanism.

Other coupling arrangements for connecting the cam and the base grip are possible. For example, a pivotal link might be employed, in which an arm or bar is pivotally connected to both the cam and the base grip, the arm pulling the base grip around with the cam, and the pivotal connections allowing the necessary sliding motion between the cam and the base grip to change the separation of the gripping surfaces.

Any other connection may also be used that is able to accommodate the appropriate relative motions.

Figures 3A to 3E show a series of side views of the cam 38 and the base grip 30 throughout the gripping operation. In Figure 3A, gripping has not yet begun, and the rope 24 is free to run between the upper gripping surface 36 and the lower gripping surface 26. The cam 38 is in its extreme anticlockwise position, with the pin 42 at the top of the arcuate portion 44a of the slot 44. The base grip 30 hangs from its axle 34 so that the plate 28 and hence the lower gripping surface 26 slope slightly downwards.

In Figure 3B, the cam 38 has turned clockwise somewhat so that the upper gripping surface 36 has made contact with the rope 24 and begun to compress it. The pin 42 is travelling along the arcuate slot portion 44a. This produces little or no motion in the base grip 30, so the lower gripping surface 26 has not moved significantly and is not yet contributing much to gripping the rope 24.

In Figure 3C, the cam 38 has rotated further clockwise so that the pin 42 has passed in the linear slot portion 44b and begun to pull the base grip 3D around clockwise. The lower gripping surface 26 has moved past the horizontal and is moving on an upwardly sloping path towards the upper gripping surface 36, which continues to move downwards with the rotation of the cam 38. The spacing between the two gripping surfaces 26, 36 decreases, and both surfaces are gripping the rope 24.

In Figure 3D, the cam 38 has reached the extreme clockwise position of its rotation path, and is prevented from turning further by the pin 42 having reached the bottom end of the linear slot portion 44b. The two gripping surfaces 26, 38 have been pulled close together by the reactive motion, and the rope 42 has been gripped quickly and tightly.

Figure 3E shows the same positioning as in Figure 3D, but in a cut-away view in which the near side wall of the base grip 30 has been removed. The toothed gripping io surfaces 26, 36 can be clearly seen holding fast to the rope, which is compressed and held both above and below.

A release mechanism is provided in the device of Figure 2 to release the gripped rope 24. The mechanism is operated via the handle 16. A clip 48, for example in the form of an elongate ring or loop made from metal, alloy or plastic, and positioned inside the housing 12. is attached in a hinged manner at one end to the underpart of the handle 16 near the handle axle 18. At its other end it is hooked over a peg 50 or other protrusion extending upwardly from the top of the cam 38, with some play in the arrangement so that clip 48 is not tightly around the peg 50. Thus, the cam is coupled to the handle 16. Also, a rigid release arm 46 couples the base grip 30 to the handle 16.

The release arm 46 is attached at one end to a tower part of the base grip 30, remote from the base grip axle 34. The attachment may be fixed or pivoting, depending on the relative positions of the various components and the range of movements desired. The release arm 46 extends within the housing 12 to the vicinity of the Se-end of the handle 18, and terminates In a protruding lug 52 below the end of the handle 16.

To release the gripped rope 24, the handle 16 is lifted from its closed position and rotated about its axle 18 to a substantially vertical position. During this motion, the dip 48 is pulled by the handle 16 to reduce the spacing between the dip 48 and the peg 50. The rope remains gripped. As the handle 16 is turned past the vertical position, the clip 48 engages against the peg 50 and continued motion of the handle 16 pulls on the peg 50 via the clip 48. This rotates the cam 38 about its axle 40 in an antidockwise direction (as viewed in Figure 2), thereby moving the upper gripping surface 36 away from the lower gripping surface 26. At the same time (or a little before or after, depending on the exact sizes and positions of the components), the end of the turning handle contacts the lug 52 on the release arm 46, and pushes against it. This push is transferred along the arm 46 to the base grip 30, so that the base grip 30 Is also pushed, and hence rotates antlclockwise about its axle 34. This turning moves the lower gripping i3 surface 26 downwards away from the upper gripping surface 36 which, in turn, rotates the cam anticlockwise through the action of the pin 42. These motions continue untU the gripping surfaces 26 and 36 have moved suffcienfiy far apart to r&ease the rope 24.

Figures 4A to 4D show a sedes of side views of the cam 38, the base grip 30 and the handle 16 throughout the release operation. n Figure 4A, release has yet to begin, and the rope 24 is rmly gripped between the upper and lower gripping surfaces, as shown in Figures 3D and SE. The handle 16 is "closed", folded flat over the top of the housing (not shown). The clip 48 Is loosely hooked over the peg 50, without being in engagement with t. The release arm 46 is extending from the base grip 30 into the area io below the handle axle 18.

Figure 4B shows the handle 16 having been rotated about its axle 18 into an intermediate position in which it extends vertically upwards. Release is about to commence, although as yet the cam 38 and the base grip 30 have not moved from the gripping position. The pin 42 is still at the bottom of the linear slot portion 44b.

In Figure 40, the handle has been rotated past the vertical position, and release is underway. The release arm 46 comes into effect first. The end of the handle 16 has been brought into contact with the lug 52 on the end of the release arm 46, and has pushed on the release arm 46. The release arm 46 has in turn begun to act on the base grip 30 to which it is connected, to push the base grip 30 anticlockwise about its axle 34.

This turning of the base grip 30 swings the lower gripping surface downwards and away from the underside of the lope 24 so that the lower gripping surface begins to disengage from the rope 24. In Figure 40, the lower gripping surface has reached a horizontal position. The pin 42 is in the linear slot portion 44b, and the movement of the base grip causes the side of the slot to act against the pin 42, thereby pushing the cam in an anticlockwise rotation also, so that the upper gripping surface begins to lift away from the top of the rope. This is the opposite effect to the pulling of the base grip by the cam during the gripping action shown in Figures 30 and 3D. The pin 42 moves up the linear slot portion 44b and as shown in Figure 4C is about to enter the arcuate slot portion 44a.

In Figure 40, the handle has been turned further, through about 180 degrees in total so that it is roughly horizontal again. This additional movement of the handle has engaged the clip 48 with the peg 50, and pulled on the peg 50. The cam 38 has thereby been further rotated anticlockwise about its axle 40, this time by a pulling action, so that the upper gripping surface is lifted further away from the top of the rope 24 to completely disengage from the rope 24. In doing so, the pin 42 has moved to the top of the arcuate slot portion 44a. Also, the further movement of the handle has continued to push on the release arm 48, producing a further rotation of the base grip 30 until the lower gripping surface is whofly disengaged from the underside of the rope 24. The rope is therefore released on both sides, and is again free to move through the housing.

Note that the release is achieved by the combined effects of puFirig on the cam and pushing on the base grip, both brought about by a single movement of the handle.

One can envisage other arrangements, for example in which the cam is pushed and the base grip is pulled by a handle that is pivoted at the opposite end of the housing. Also, adequate release might be achieved by pushing or pulling one or other of the cam and the base grip alone.

Also, the connection points of the clip 48 and the release arm 46 with the cam 38, base grip 30 and handle 16, and the lengths of the clip 38 and the release arm 46, can be selected to set the order of the release procedure, ie. whether the top or bottom of the rope 24 is released first or if they are released at the same time. The release process can therefore be closely defined.

As described previously, both the cam 38 and the base grip 30 are coupled to the module unit 20. The module unit 20 is removably engaged with the housing 12, such that it can be locked to the housing 12 by means of the screw 22 (in this embodiment).

Figure 5 shows an external perspective view of the device 10 without any cut away parts so that the outer configuration of the device 10 can be seen. The principal parts include the housing 12, through which the rope 24 passes from one end to the other, and which is surmounted by the handle 16 pivotable about its handle axle 18 which is mounted directiy to the housing 12, The module unit 20 is engaged with an upper part of the housing 12 below the closed handle 16, to form an extension of the sides of the housing 12. The module unit 20 is fastened to the housing 12 by the screw 22. The edges of the module unit 20 and of the housing 12 are formed in this example to have complementary shapes with a small overlap so that the two parts fit smoothly together and can easily be engaged in the correct posifions.

The cam axle 40 and the base grip axle 34 are both mounted on the module unit 20, and not on the housing. Hence, both the cam 38 and the base grip 30 are coupled to the module unit and not to the housing. Removal of the module unit 20 from the housing 12 by unfastening the screw 22 and pulling the module unit and the housing apart, after lifting of the handle 16, also removes the cam 38 and the base grip 30 from the housing.

In embodiments featuring a release mechanism such as that shown in Figures 4A-4D, it is also necessary to unhook the clip 48 from the peg 50 when removing the module unit 20 from the housing 12. However, since these two components are not tightly engaged when the handle 16 in a vertical position, this does not impede the i c_ detachment of the module una 20. Alternatively, the cUp might be unhooked from its mooring under the handle.

The module unit 20, the cam 38 and the base grip 30 can therefore be thought of as a single module, removably engagable with and fastenable to the housing 12. This is a parbcularly beneficial arrangement, because both the cam and the base grip can be removed from the housing while the housing remains fastened to the deck or other surface on which it is mounted. Cleaning, servicing, pads replacement and other maintenance can therefore be carried out with great ease. In particular, both gripping surfaces can be removed from the housing for cleaning, so that a good grip performance can be maintained. This is in contrast wth known designs having a cam and a fixed lower gripping surface. In these designs, the lower gripping surface is integral with the housing and cannot be easily accessed for cleaning, nor can it be removed from the in situ position without detaching the entire device from its mounting surface.

Figure 6 shows the module formed from the module unit 20, the base grip 30 and is the cam 38, removed from the housing 12. The handle 18 has been opened to allow the module to be lifted from the housing 12, once the screw 22 has been removed from the cooperating bores 23a, 23b in the module unit 20 and the housing 12.

The removable module feature is made possible by coupling the cam and the base grip to proximate areas of the housing. These areas, because they are proximate, can be defined to be on a separate, removable part of the housing, namely the module unit. The cam and the base grip provide the two gripping surfaces, which must necessarily be located on opposite sides of the rope. Therefore, it is necessary to link the lower gripping surface, which is underneath the rope, to the module unit at the upper part of the device where the module unit is attached. In the invention, this is achieved by the U-shaped base grip, which allows the lower gripping surface to depend from the module unit. This is in contrast to known earn-based designs where the lower gripping surface is integrally formed with or fixed to the bottom surface of the housing, under the rope.

In the examples described above, the cam and the base grip are both pivotally coupled to the module unit, by their respective axles. This is a feature of the reactive gripping or clutching. However, the modular feature, in which the cam and the base grip are both removable from the housing via the single module unit, may also be implemented without the reactive clutching. For example, the base grip can depend from the module unit by a rigid coupling, for example a nonpivoting fastening or by being integrally formed therewith. In such an arrangement, the rope is gripped by the movement of the cam alone, as in the prior art device of Figure 1. The slot in the base 1 6 grip and the pin on the cam wifi nt he needed for such an arrangement. Other configurations of the base grip may also be envisaged; any arrangement that suspends or depends the lower gripping surface from the module unt with sufficient strength to Slow the cam to grip the rope between the two gripping surfaces may be employed.

On the other hand, the reactive clutching may be implemented without the modular feature. The cam axle and the base grip axle may be mounted directly to the housing, and not on a part of the housing that is removable therefrom, such as the module unit.

Further, the rotatable mounting of the cam and the base grip may be implemented by structures other that the illustrated axles. For example, pivot pins formed on and protruding from the sides of the cam and the base grip may replace the axles. The pivots pins or the axles might be received into recesses on the inside surface of the module unit or housing, instead of extending through the walls of the module unit to the exterior as iflustrated.

In any combination of reactive clutching and modular design, the device may be configured as a multiple design for securing more than one rope. Two, three or more gripping units are arranged side-by-side to hold parallel ropes, with the housings of each unit formed together as a single multiple housing to receive multiple cam and base grip pairs, with a handle for each pair. In a modular design, each cam and base grip pair is separately removable from the housing.

Other modifications of the various components of the device that provide the same functionality and operate similarly will be apparent to the skilled person, and such modifications are intended to fall within the scope of the invention. The invention is not limited to the precise structures illustrated.

The rope-gripping device may be exposed to water (fresh or salt) in use, so the various components of the device preferably should be made from materials resistant to rusting and other corrosions, such as metal alloys, stainless steel and moulded plastics.

The device has been described in the context of holding or gripping ropes, but it may also be used for holding other similar items, such as braids, webbing, tape, lines and other flexible elongate items or materials. Hence, the invention is not limited to the gripping of ropes, and the appended claims are intended to cover the gripping of any similar item. Hence, the term "rope" in the description and the claims is to be understood as including all flexible elongate items and materials employed in circumstances where a gripping, holding or securing function is required. -i7

The descripUon has discussed the device in the context of sailing, but the invention a not so limited. The device may be employed for rope gripping appcations in nonmanine industhes, occupations and pastimes.

While the various embodiments of the device have been described as 1 fastened through the base to a horizontal surface such as a deck, using terms relative to this orientation such as upper, lower, top, bottom, horizontai and vertical, the device may of course by fastened to a vertica surface or other non-horizontal surface. Also, the device may be configured to be mounted on its side rather than on its base. Relative directional terms should therefore be interpreted accordingly, appropriate to the orientation of the iO device in use.

Addifionaily, attachment of the device to a surface is not limited to a mounting by which bolts or screws are passed through apertures in the housing. Alternative attachment arrangements are also envisaged, such as adhesive bonding, or a sliding or push mount whereby the device is engaged into slots, grooves or the like on a separately mounted base receptacle. Any mounting arrangement may he either via the base or a side of the device.

Claims (13)

1. CLAIMS1. A rope-gripping device comprising: a housing configured to receive a rope extending therethrough; a module unit removably engagable with the housing; an eccentric cam having a first gripping surface defined on its perimeter, and rotatably mounted on the module unit for rotation about an axis perpendicular to the extent of a received rope; a base grip depending from the module unit and supporting a second gripping surface in an opposed configuration to the first gripping surface such that the first and second gripping surfaces define a space therebetween for receiving the rope for gripping; and a spring acting on the cam to bias rotation of the cam in a direction that brings the first gripping surface closer to the second gripping surface to decrease the space Is therebetween and grip the received rope; wherein the earn and the base grip are received within the housing when the module unit is engaged with the housing, and removed from the housing when the module unit is disengaged from the housing.
2. 2. A rope-gripping device according to claim 1, in which the module unit has side walls that align with and extend side walls of the housing when the module unit is engaged with the housing.
3. 3. A rope-gripping device according to claim 1 or claim 2, further comprising a fastener to fasten the module unit to the housing when the module unit is engaged with the housing.
4. 4. A rope-gripping device according to claim 3, in which the housing and the module unit have cooperating bores that are aligned when the module unit is engaged with the housing, and the fastener comprises a screw engagabie in the bores.
5. 5. A rope-gripping device according to any preceding claim, and further comprising a handle pivotably mounted at one end to the housing and coupled to one or both of the cam and the base grip such that turning of the handle acts to move one or both of the cam and the base grip to increase the spacing between the first gripping surface and the second gripping surface and release a gripped rope.-19***
6. 6. A rope-gripping device according to daim 5, in which the handle is pivotably mounted on the housing for turning about an axis paraDeD to the axis of rotation of the cam.

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7. 7. A rope-gripping device according to claim 5 or claim 6, in which the handle is turnable between a closed position folded against the housing and a release position in which the spacing between the first gripping surface and the second gripping surface is increased, and in which the module unit when engaged with the housing Dies between the housing and the handle in its closed position.
8. 8. A rope-gripping device according to any preceding claim, in which the base grip depends from the module unit by a mounting that allows rotation of the base grip relative to the module unit about an axis parallel to the axis of rotation of the cam, rotation of the base grip causing movement o the second gripping surface towards and away from the first gripping surface.
9. 9. A rope-gripping device according to claim 8, in which the first gripping surface and the second gripping surface are moved towards each other and away from each other to decrease and increase the spacing therebetween by rotation of the cam and rotation of the base grip ri the same direction.
10. 10. A rope-gripping device according to claim 8 or claim 9, in which the mounting of the base grip comprises a base grip axle on which the base grip is mounted, the axle supported cn the module unit.
11. 11. A rope-gripping device according to any preceding claim, in which the cam is mounted on the module unit by a cam axle on which the cam is mounted, the cam axle supported on the module unit.
12. 12. A rope-gripping device according to any of claims ito 7, in which the base grip depends rigidly from the module unit.
13. 13. A rope-gripping device substantiaDy as described herein with reference to Figures 2 to 6 of the accompanying drawings.