CN1344358A - Improvements in or relating to tripod stands - Google Patents

Abstract

A tripod stand for supporting equipment such as a TV camera or the like comprising a mounting (10) for the equipment having a central axis and three telescopic legs (17, 18) extending from the mounting, the legs having head ends (40) pivotally attached to the mounting at locations equi-spaced around said central axis of the mounting to allow the legs to fold together in a closed position and outwardly to an erect position in which they diverge in tripod form from the mounting, and foot ends (50, 51) to engage the ground or other surface on which the stand is to be used. Each leg comprises a plurality of slidably engaged interlocking channel section members (17, 18, 19) facing outwardly of said axis to extend and retract with respect to one another. One of said members (17) is being pivotally attached to the mounting to swing between said folded and erect positions and each of the further members having menas to lock the member in any position of extension/retraction with respect to the adjacent member to later the height of the tripod stand.

Description

Tripods or improvements related thereto

The present invention relates to tripods and is especially, but not exclusively applicable to tripods for devices such as television cameras.

A tripod for a television or video camera comprising a camera mount and three telescopic support legs, each leg having a head end and a foot end, the head ends being pivotally attached to the mount at positions equally spaced about the mount, Such tripods are well known in order for the support legs to fold together in a closed position and outwardly to an erected position where they diverge from the mount in the form of a tripod with the feet engaging the ground. Our European Patent No. 0541579B discloses a tripod in which each support leg comprises an upper part consisting of two parallel tubes connected at their upper and lower ends by cross pieces, the upper cross pieces being pivotally connected on the camera mount to fold the support legs between the inward packing position and the outward erecting position. The central part of the supporting legs also comprises a pair of parallel tubes spaced so as to slide between the tubes of the upper part and still connected at their upper and lower ends by a junction. The tube of the central part slidably extends in the bore of the lower transition of the upper part, and the upper transition of the central part slidably engages the tube of the upper part. Locking means are provided on the upper transition of the central part to lock the central part in any position relative to the extension of the upper part. The bottom part of the support leg comprises a tube slidably engaged in the bore of the lower transition of the central part, a transition at its upper end slidably engaging the tube of the central part, and a support foot at its lower end. Locking means are provided on the lower transition of the central part to lock the lower part in any position extending relative to the central part. With the support leg members fully retracted, the lower junction of the center member abuts the lower junction of the upper member and the support feet of the bottom member abut the junction of the center member. It is not possible to fully retract the bottom and central part into the upper part so that the support legs cannot be made as compact as desired.

Also, the operator prefers that the locking means for each extendable leg member be located on that member rather than on a non-moving member so that the release and extension of the leg can be done with one hand rather than needing to be loosened lock on a non-moving part and then adjust the movable part in another operation.

In order to avoid this disadvantage, the present invention provides a tripod for supporting equipment such as a television camera, the tripod comprising a mounting base for the equipment with a central axis, and three telescopic brackets extending from the mounting base. Support legs having head ends and foot ends pivotally connected to the mount at positions equidistantly spaced about the central axis of the mount such that the support legs can be folded together in a closed position and outwardly to an erected position , wherein in the erected position they diverge from the mount in the form of a tripod with the feet engaging the ground or other surface on which the column is to be used, each support leg comprising a plurality of slidably engaging interlocking channel members facing the outside the axis, telescoping relative to each other, one of said parts is pivotally connected to the mount for swinging between said folded and erected positions, and each of the other parts has the function of locking the part in relative to the closest A device for extending/retracting any position of the adjacent parts of the mount, thereby changing the height of the column.

In a preferred arrangement, the cross-section of the parts from the mount end to the foot end tapers, with each successive part along the support leg from the mount end to the foot end being slidably engaged in the preceding part.

In any of the above arrangements, the locking means may comprise an elongated member on each of said other members, extending along the length of the member adjacent the inside of one of its side walls, and may be connected to another The outer side of the part that slides on, the element engages at its end about an axis extending along the length of the part, in a position where the other part is free to slide relative to the part and the locking element is between the side walls of these parts is rotatably mounted on the part between positions that form a snap-fit engagement to lock the parts together.

In the latter arrangement, the locking elements on each of said other parts are arranged to pass through the center when the proximate support leg part is in locking engagement with an adjacent part while retaining the locking element in said locking engagement therewith. outside.

In either of the preceding arrangements, means may be provided to eliminate lateral clearance between adjacent support leg members parallel to the pivot axis.

More precisely, the means for removing the gap between adjacent supporting leg parts may comprise elongated cams mounted on said one part and subsequent parts along said supporting leg up to the penultimate part, whereby Acts on the overlap of the next part along the support leg to remove gaps between parts.

According to another characteristic of the invention, the cross-section of the part is such that the bending axis of each supporting leg is aligned with the point at the foot end of the supporting leg at which the reaction force from the ground acts on the supporting leg, so that the Side loads on the support legs do not cause twisting of the support legs about which axis they pivot relative to the mount.

In the latter case, the part at the head end of each supporting leg may have a double grooved portion forming a grooved shape facing both sides of the supporting leg, the grooved portion on one side of the supporting leg receiving a slidable engagement therein. The next channel part, and the channel part on the other side of the support leg, positions the bending axis of the support leg so as to extend through the point of application of the reaction force at the foot end of the support leg as described above.

In any of the above arrangements, the foot end of each leg may have attached thereto an angled ground-engaging foot member, the foot member being attached to the leg so that the load applied to the leg is parallel to the The direction of the pivot axis of the support leg and the mounting seat passes through the bending axis of the support leg and acts on the foot end of the support leg.

Furthermore, portions of the supporting leg members may be such that the bending axis of the supporting leg intersects the corresponding pivoting axis of the supporting leg at the mount.

According to another feature, the parts of the supporting leg part are such that the bending axis of the supporting leg intersects the corresponding pivot axis of the supporting leg at the mount.

In another configuration according to the invention, the locking means may comprise elongate gripping means protruding from one side wall of the slot to engage on the opposite side of the outer slot and provided with telescoping of the gripping means to lock and release the slot installation.

For example, the clamping means may comprise an elongated clamping member and an elongated drive member acting on the clamping member, wherein longitudinal movement in a direction causes the clamping member to extend into clamping with the side wall of the adjacent slot engage, and release the clamping action in the other direction.

More specifically, the elongated drive member may have a series of shallow serrations spaced along its length engageable with corresponding serrations on the clamping member such that movement of the drive member in one direction causes the clamping The member is spaced away from the side wall of its respective slot into clamping engagement with the side wall of an adjacent slot.

In a particular arrangement, the elongate gripping member and the elongate drive member may have other means of interengaging which enable the gripping member to move in said opposite direction from gripping engagement with the drive member. voluntarily returned.

In a preferred configuration according to the invention, said channel member on which the clamping means is mounted may have an elongated side channel extending the length of the side wall in which the clamping member and the cam member are mounted.

In the latter arrangement, guide means may be provided to guide the drive member linearly along the slot, wherein movement in one direction displaces the gripping member outside of the slot and movement in the opposite direction retracts the gripping member into the slot.

It is preferred that means are also provided for pre-adjusting the position of the clamping member relative to the drive member in order to minimize movement before the clamping member acts on the side wall of the next slot.

Preferably the drive member of each slot is displaced along its respective slot by manipulator means at one end of the slot.

More precisely the manipulating means may comprise a lever rotatably mounted at said one end about an axis extending transversely to the support leg and interconnected with the cam member so as to displace the cam member with rotation of the lever.

Below is the description of the embodiment of the invention done with reference to the accompanying drawings, wherein:

Fig. 1 is the perspective view of the tripod for TV or video camera of the present invention;

Fig. 2 is a cross-sectional view of a support leg passing through the tripod;

Figure 3 is a perspective view of another camera tripod of the present invention in a fully folded form;

Figure 4 is a perspective view of the tripod shown in Figure 3 in a fully erected form;

Figure 5 is a front view of one support leg of the tripod partially extended;

Figures 6 to 9 show in perspective the upper part of a trough section with elongate clamping means extending lengthwise along one side of the trough for clamping the respective trough sections together , the clamping device is manipulated by the bell crank lever and the associated mechanism shown in the release position of FIGS. 6 and 8 and the locked position of FIGS. 7 and 9;

Figures 10 and 11 show in side view the upper end of the channel portion of Figures 6 to 9 with the bell crank in respective locked and released positions;

Figures 12 and 13 are another perspective view of the upper end of the channel section with the bell crank lever used to operate the omitted locking mechanism;

Figure 14 is a plan view of the trough portion of Figures 12 and 13;

Figure 15 is a perspective view of the elongated clamping member and corresponding drive member shown separately for clarity;

Figure 16 is a longitudinal sectional view through the clamping and drive member, showing the clamping member in a retracted position relative to the drive member; and

Figure 17 is a similar view showing the clamping member extended by the drive member.

Referring first to Figure 1, there is shown a tripod for a television or video camera comprising a mount 10 adapted to receive and support the camera. The mount is generally circular and has three equidistantly spaced grooves or sockets about its periphery in which the upper ends of the extendable support legs 12 are hinged about the shaft axis, one of the pivots being designated 13, The support legs can be folded inwardly to a stowed position and outwardly to an erected position to form a tripod, so that the tripod is supported on the ground or other surface to be used.

Referring now to FIG. 2, one of the supporting legs shown in a fully retracted form comprises an upper part 17 of generally I-beam section form with channel-shaped portions 18, 19 formed on both sides thereof, and the groove 18 of the upper part may be An inner slidably engaging intermediate channel member 20 and a lower channel member 21 slidably engageable within the channel portion of the intermediate member.

The upper end of the intermediate part 20 has an abutment 22, the ends of which protrude beyond the sides of the part for purposes which will be more apparent below. The lower end of part 20 has a similar interface. The two transition pieces are shaped or cut so that the upper and lower trough members pass through when the support legs are telescopic as described above.

The trough 18 of the part 15 has converging side walls 23 between which an intermediate support leg part 20 is provided, and they are laterally constrained but longitudinally free to slide. The inner side of one wall of the channel 18 has a groove 24 , while the adjacent side wall 25 of the intermediate channel part has a corresponding groove 26 . An elongate double scroll cam element 27 extends between side wall 25 and side wall 23 which engage in grooves 24 and 26 to provide the pivot axis of middle member 18 relative to upper member 15, and Lateral adjustment of the middle part over the upper part is provided by rotationally adjusting the cam element, thereby eliminating lateral play between the two parts.

The cam elements are mounted at their upper and lower ends for rotational adjustment at the upper and lower interface ends of one side of the intermediate part 17 . On the other side of the slot, the inner surface of the side wall 23 is formed with an angled groove 30 having a rounded apex 31, and the adjacent side wall 32 of the intermediate support leg member has a similar angled recess. Groove 33 with a concave apex 34. The elongated detent element 34 of triangular cross-section has vertices 36, 37 joined between vertices 31, 34, respectively. The brake element is pivotally mounted at its upper and lower ends on the upper and lower end transitions on the other side of the middle part of the supporting leg. The lever is connected at its upper end to the detent member for turning the detent member thereby locking and releasing the upper and middle channel members together, as described below.

The detent element 35 pulls the middle channel part out of the upper channel part until one side of the triangular part rests on the outermost surface 30a of the inner angled groove of the channel side wall 21 by turning the part in a counterclockwise direction. And release. In this position, the middle part is free to slide relative to the upper part for telescoping as required. When the middle part reaches the desired position, the locking part turns clockwise, pulling the middle part into the upper channel part. Finally, the apex of the triangular part and the apex 34 of the central slot pass the dotted line 40 "over center" to a stable position just above "over centre", wherein one side of the triangular part passes through the center of the central slot. A stop (not shown) between the bottom wall of the part and the bottom wall of the upper trough part supports against further turning into the trough.

The cam element 25 has previously been adjusted so that in this position the detent element, the intermediate trough part and the rotating cam part remain compressed between the side walls of the trough, thereby locking the intermediate part against movement. A similar arrangement is provided on the bottom channel member to remove play and achieve locking engagement with the middle member.

The lower end of the bottom channel member has support feet attached thereto for engaging the ground or other surface on which the tripod is intended to be used. The upper channel member 17 is shown as having an I-shaped cross-section, and the cross-sectional depths and wall thicknesses of all channels are such that the bending axes of each channel member are coincident, ie aligned in the lengthwise direction of the support legs. Thus, the bending axis about which the support leg bends in lateral movement extends to the point where the support foot is connected to the bottom end of the support leg, and also passes through the pivot axis at the upper end of the support leg. Therefore, side loads on the supporting legs do not twist the supporting legs.

The parts of the support legs may be made of carbon fiber reinforced plastic or may be high strength aluminum alloy extrusions. The bottom part of each support leg is shown as a channeled section to provide visual consistency with the middle and upper parts, but it should be readily understood that since the bottom part has no nesting parts it does not actually have to be slotted . Instead, it can be a closed tube or just a solid section.

Referring now to another embodiment shown in Figures 3-5, like parts to those of the first embodiment bear the same reference numerals.

As described in our prior application, each extendable support leg 12 of the tripod comprises an outwardly facing upper channel member 17 having a pivot molding 40 secured to its upper end, in which Integral molded trunnions 41 protrude from both sides of the piece to engage corresponding sockets on both sides of the groove of the mount 10 . The lower end of the part 17 has secured thereto a guide molding 42 which has a front opening 43 so that the next channel part 18 can slide in and out of the upper part 17 . Adjustment cam 27 as described in our earlier application is rotatably mounted at its upper and lower ends on moldings 40 and 42 respectively and adjacent to inner side wall 17a of upper part 17 . The cam 27 is engageable with the outside of the next channel member 18 of the support leg, where the member 18 protrudes into the upper member 17, as described in our prior application.

The channel-section part 18 is closed at its upper end by a molding 45 fastened thereto and at its lower end by a guide molding 46 similar to the molding 42 . Furthermore, the molding 46 has a front opening 47 through which the next channel-section part 19 passes.

The adjustment cam 27 as previously described is mounted at its ends in the moldings 45 and 47 of the part 18 in the vicinity of the side wall 18a of this part similar to the mounting of the cam 27 of the upper part 17 . Elongated detent member 35 extends along the length of member 18 and is rotatably mounted at its upper end in molding 45 and its lower end 46 is mounted on the outside of side wall 18b of the member to engage the side wall of the upper member Inside of 17b. The detent member is pivoted between a locked position and a released position by a molded lever 48 attached to its upper end, in which the lever 48 is flush with part 18 and the detent part is on the side walls 17b and 18b of parts 17 and 18 respectively. In the released position, the member extends outwardly of the support leg 18 and the member 18 is free to slide relative to the member 17, as described in our earlier application. Cam 27 is pre-adjusted to absorb excess slack between parts 17 and 18 and provide the proper amount of clearance between the parts for smooth sliding in the released position and proper locking between the parts in the jammed position.

In addition to replacing the lower molding 46 with the opening, the last innermost part 19 of the supporting leg is formed similarly to the middle part 18, and has a supporting foot molding 50 fixed thereon, fastened by protruding pins 51. the ground or other surface on which the tripod will be used. Part 19 has a detent member 35 pivotally mounted in the upper and lower moldings of the part near the outside of side wall 19a of the part and operated by lever 52 .

It can be seen from the arrangement of Fig. 1 that when the supporting leg parts 18 and 19 are fully retracted in the upper part 17, the brake levers of the two parts 48 and 52 are located side by side on top of the supporting legs in relation to the pivot mold. Part 40 is flush. To extend one of the supporting leg members, the corresponding lever 48 or 52 is rotated to its release position and used to slide the supporting leg member outwards to the desired position for extension. The lever then returns to its locked position. Thus, each support leg member can be extended relative to its neighbor by a manual action, rather than a trombone-like sliding action.

Referring now to an alternative arrangement shown in FIGS. 6-17 , the upper trough portion 20 of the support leg has an outwardly opening side trough 60 closed at its lower end by an end wall not shown and open at its upper end as marked 61 shown here. The side channel houses an elongated clamping member 62 and a corresponding elongated drive member 63 located behind the clamping member in the channel. The drive member 63 has a T-shaped cross-section and the rear of the side slot has a corresponding T-shaped cross-section, thereby restricting the drive member from moving up and down in the slot.

The clamping and drive components 62, 63 are better shown in Figures 15-17, to which reference will now be made. The clamping member 62 has an elongated front wall, which is provided with an elongated clamping face 64, side walls 65, and is open at the rear. Integral serrated teeth 66 are formed on the clamping member at regular intervals along the member between the side walls.

The drive member 63 has corresponding sawtooth teeth 67 spaced along its length for engagement with the teeth 66 of the clamping member between the side walls 65 of the clamping member.

As previously shown, the lower end of the side slot 60 is closed by the end wall, and a headless screw is installed in the wall to adjust the vertical position of the clamping part 62 relative to the driving part 63, so that the clamping part can be preset close to the outer slot On the closed side of the part, the inner groove 20 in the outer groove part engages to be clamped and released to the outer groove, as described below.

The drive member 63 has a slot 68 on its rear side adjacent the top of the drive member to be engaged by a mechanism for raising and lowering the drive member, as will be described later.

Referring to Figures 16 and 17, a number of teeth 67 on the clamping member are replaced by angular ribs 69 on one side 65 of the member. These angular ribs engage in angular grooves 70 on the sides of the corresponding teeth on the drive part 63 . As the drive member 63 is pushed downwards, the interaction of the ratchet teeth pushes the clamping member 62 laterally, as shown in Figure 17, to clamp with the adjacent side channel of the next channel section member. As the clamping member is lifted, the interaction of the ribs 69 in the groove 70 retracts the clamping member 62 as shown in FIG. 16 .

A manipulation mechanism for lifting and lowering the driving member 63 relative to the side groove 60 to release and clamp the clamping member 62 will now be described.

A housing for enclosing the operating mechanism (omitted for clarity) is integrally formed with the top end of the channel portion 20 . The housing supports a laterally extending shaft 71 for rotation about a laterally extending horizontal axis of the trough portion. A block or prism 72 of triangular cross-section is molded on shaft 71 so as to rotate with side channel 60 at an apex of the prism near its upper open end. A crank pin mounted on the second apex of the prism 73 is slidably received in the slot 68 at the upper end of the drive member 63 . When the block rotates with the shaft 71, the drive member 63 is raised and lowered in the side slot. Shaft 71 also has an integrally formed crank arm 74 spaced from one side of prism 72 .

The housing also supports a bell crank lever 75 on a pivot 76 . A portion of the lever 77 protrudes from the housing for raising and lowering the lever about the pivot 76 as shown in FIGS. 10 and 11 . The other part of the lever comprises spaced apart cheeks 78 between which a roller 79 is rotatably supported. When the lever pivoted between its stowed position shown in FIG. 10 and its released position shown in FIG. position and its release position shown in Figure 11, in the upright position the drive member 63 is in its lower position and the clamping member 62 is extended into engagement as previously described, in the release position shown in Figure 11 the prism The body rotates with the shaft 71 to lift the side member 63, thereby releasing the clamping action of the clamping member 62.

Lifting the drive part 63 to ensure that the prism turns, the shaft with the roller 79 on the bell crank lever protrudes on the inside of the slot 17 to engage on the crank arm 74 and drives down when the bell crank lever 77 lifts The arm, which is better shown in FIGS. 6 and 11 .

A similar mechanism is provided at the other end of the next trough section 21 down the support leg, with the steering mechanisms positioned sideways so that when the trough section is fully retracted, the actuating mechanisms approach each other.

The supporting legs of the tripod are telescopic in the above-mentioned manner, so that the tripod can be erected, adjusted or folded as required.

Claims (19)

1. A tripod for supporting equipment such as a television camera, the tripod comprising a mounting base for the equipment having a central axis and three telescopic support legs extending from the mounting base, the supporting legs having Erection means pivotally connected to the mount at positions equidistantly spaced around said central axis of the mount such that the support legs fold together in the closed position and outwardly so that they diverge from the mount in the form of a tripod The head end of the tripod, and the foot end of the ground or other surface to be used to engage the tripod, each support leg comprises a plurality of slidably engaging interlocking channel members facing outwardly of the axis so as to be mutually Relatively telescoping, one of the members is pivotally connected to the mount for swinging between the folded and erected positions, and each of the other members has the ability to lock the member in relation to the adjacent adjacent member closest to the mount. A device at any point where the part extends/retracts in order to change the height of the tripod. 2. A tripod as claimed in claim 1, characterized in that the members successively decrease in cross section from the mount end to the foot end, each successive member along the support leg from the mount end to the foot end slidably engages in the previous part. 3. A tripod as claimed in claim 1 or 2, characterized in that the locking means are included on each of the other parts extending along the length of the part near the inside of one side wall thereof and on which an elongate element engageable with the outside of a next part, at its ends about an axis extending along the length of the part, in a position where said next part is free to slide relative to that part and locked The element is rotatably mounted on the part between positions of snap engagement between the side walls of the parts, thereby locking the parts together. 4. A tripod as claimed in claim 3, characterized in that as it approaches the locking engagement of a supporting leg member and an adjacent member, holding the locking member in said locking engagement therewith, in each of said other members The locking elements on are arranged past the center position. 5. A tripod as claimed in any one of the preceding claims, characterized in that means are provided for eliminating lateral play parallel to the pivot axis between adjacent support leg members. 6. A tripod as claimed in claim 5, characterized in that the means for eliminating gaps between adjacent supporting leg parts comprises subsequent parts mounted on said one part and along the supporting leg up to the penultimate part The elongated cam on the support leg acts on the overlapping part of the next part along the support leg to eliminate the gap between the parts. 7. A tripod as claimed in any one of the preceding claims, characterized in that the cross-sections of these parts are such that the bending axis of each supporting leg and the reaction force of the ground at the foot end of the supporting leg act on the supporting leg The points are aligned such that a side load acting on the support leg generally parallel to the axis of pivoting of the support leg relative to the mount does not cause the support leg to twist. 8. The tripod as claimed in claim 7, wherein the part at the head end of each supporting leg has a double groove portion, forming a groove shape facing both sides of the supporting leg, and the grooved portion on one side of the supporting leg The next channel member slidably engaged is accommodated therein, and the channel portion on the other side of the support leg forms a bending axis for positioning the support leg, extending through the foot end of the support leg as previously described The point where the reaction force acts. 9. A tripod as claimed in claim 7 or 8, wherein the foot end of each support leg has a ground engaging support foot member attached thereto at an angle, the support foot member being attached to the support leg, A load applied to the support foot is caused to act on the foot end of the support leg through the bending axis of the support leg in a direction parallel to the pivot axis of the support leg and the mount. 10. A tripod as claimed in any one of claims 7 to 9, wherein said portions of the supporting leg members are such that the bending axes of the supporting legs are aligned with the corresponding pivot axes of the supporting legs Intersect on the mount. 11. The tripod of claim 1, wherein the locking means comprises elongated clamping means protruding from one side wall of the slot to engage an adjacent side wall of an external slot, and is provided so that the clip A device that extends and retracts the holding device to lock and release the slots. 12. The tripod of claim 11, wherein the clamping device comprises an elongated clamping member and an elongated drive member acting on the clamping member, wherein longitudinal movement in one direction causes the clamping The gripping member extends into gripping engagement with the sidewall of the adjacent slot, and longitudinal movement in the opposite direction releases the gripping action. 13. The tripod of claim 12, wherein the elongated drive member has a series of shallow serrations spaced along its length for engaging corresponding serrations on the clamping member, Movement of the drive member in one direction thereby moves the clamping member away from the side wall of its respective slot into clamping engagement with the side wall of the adjacent slot. 14. A tripod as claimed in claim 12 or 13, wherein the elongated holding member and the elongated driving member have other interengaging means which cause the holding member to follow the driving member along the movement in the opposite direction described above without positive retraction from the clamping engagement. 15. A tripod as claimed in any one of claims 11 to 14, wherein the channel member on which the clamping device is mounted has a length along the side wall on which the clamping member and the cam member are mounted. Extended slim side slots. 16. A tripod as claimed in claim 15, characterized in that guide means are provided for guiding the drive member linearly along said slot so that movement in one direction brings the clamping member outwardly of said slot Displacement, with movement in the opposite direction retracts the clamping member into the slot. 17. A tripod as claimed in any one of claims 12 to 16, characterized in that means are provided for pre-adjusting the position of the clamping part relative to the drive part so that on the side where the clamping part acts on the next slot Minimize movement before hitting the wall. 18. A tripod as claimed in any one of claims 11 to 17, wherein the drive member of each slot is displaced along its respective slot by an actuating means at one end of the slot. 19. A tripod as claimed in claim 18, wherein the manipulating means comprises a lever at said one end which is rotatably mounted about an axis extending transversely to said support leg, and which is interconnected with a cam member, The cam member is thereby displaced as the lever is rotated.

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