CA1313529C - Automatically acting, lockable hoisting block - Google Patents
Automatically acting, lockable hoisting blockInfo
- Publication number
- CA1313529C CA1313529C CA000553489A CA553489A CA1313529C CA 1313529 C CA1313529 C CA 1313529C CA 000553489 A CA000553489 A CA 000553489A CA 553489 A CA553489 A CA 553489A CA 1313529 C CA1313529 C CA 1313529C
- Authority
- CA
- Canada
- Prior art keywords
- block
- plunger
- hoisting
- seat
- arms
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 230000007246 mechanism Effects 0.000 claims abstract description 16
- 230000009471 action Effects 0.000 claims abstract description 8
- 230000000295 complement effect Effects 0.000 claims description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000008901 benefit Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
Landscapes
- Load-Engaging Elements For Cranes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A hoisting block, which is lockable and automatically acting in relation to a hoisting member, is freely movable along the member, which extends from a load to be moved and to the block, such that the block can assume a desired position in relation to the load. The block includes at least one locking mechanism having comprising two arms which are pivotable in relation to the block and mutually independently, the hoisting member being arranged on the arms, a plunger actuable by a locking mechanism, and a seat disposed in the region of the plunger. A section of the hoisting member runs through a groove commonly formed by the plunger and seat and is lockable between the plunger and the seat by the action of the locking mechanism.
A hoisting block, which is lockable and automatically acting in relation to a hoisting member, is freely movable along the member, which extends from a load to be moved and to the block, such that the block can assume a desired position in relation to the load. The block includes at least one locking mechanism having comprising two arms which are pivotable in relation to the block and mutually independently, the hoisting member being arranged on the arms, a plunger actuable by a locking mechanism, and a seat disposed in the region of the plunger. A section of the hoisting member runs through a groove commonly formed by the plunger and seat and is lockable between the plunger and the seat by the action of the locking mechanism.
Description
131 ~29 The present invention relates to an automatically acting, lockable hoisting block for automatica]ly and/or manually locking a lifting member running through it, the block being intended to be disposed in any attitude in relation to the load to be lifted with the aid of the lifting member.
In hoisting blocks of the prior art having automatic locking of a rope running through the block, in which the rope is attached at both ends to a load to be lifted, locking is accomplished by a means associated with the block and turnable in relation to it, this means turning in response to tension in the rope and thus firmly clamping the rope. This type of device is described e.g.
in United States Patent No. 4,097,083. A drawback with the known device is that the block must move along the rope until both parts of the rope have been stretched, in order to achieve locking between rope and block. A
further drawback is that the locking member causes undesirable wear on the rope, with the accompanying risk of rope failure. Furthermore, the locking force ceases as soon as the load in one rope part comes against an obstruction and ceases to weigh down on this part.
Swedish Patent No. 169t695 describes another hoisting block of the self-adjusting tyæe. In this device the lifting means includes a saddle member, which has in cross-section a V-shaped groove in which the lifting rope is intended to run. The shape of the groove causes it to engage against the rope to avoid the rope slipping. This arrangement has the result that the block is very difficult to adjust in relation to the rope, and several adjustments of rope to block will be necessary before hoisting may be performed. Here as well, both rope parts must be loaded for the rope to become locked.
It is an object of the present invention to provide a hoisting block which avoids the above mentioned drawbacks and which, with an automatic and/or manual action, is lockable in an adjustable position in any attitude in relation to the load to be hoisted.
' 1~13~9 The present invention provides a hoisting block, which is lockable and automatically acting in relation to a hoisting member, the block being freely movable along the member, which extends from a load to be moved and to the block, such that the block can assume a desired position in relation to the load, wherein the block includes at least one locking mechanism, the locking mechanism comprising two arms, which are pivotable in relation to the block and mutually independently, the hoisting member being arranged on the arms, at least one plunger actuable by at least one lock mechanism, and a seat disposed in the region of the plunger, a section of the hoisting member running through a groove commonly formed by the plunger and seat, and the section of the hoisting member being lockable between the plunger and the seat by the action of said locking mechanism.
With the present hoisting block, hoisting may also take place even when the load is not in a position of equilibrium, and when the different parts of the hoisting member are unequally loaded. This also means that one of the parts can be completely unloaded during hoisting with the present block.
Embodiments of the present invention will now be described with reference to the accompanying drawings, wherein:-Figure 1 is a schematic elevation of a firstembodiment of the inventive hoisting block, with a front cover removed;
Figure 2 is a cross section through the block of Figure l; and Figure 3 is a schematic elevation of a second embodiment of the hoisting block in accordance with the present invention with the front cover removed.
A first embodiment of an inventive hoisting block is illustrated in Figure 1, the block being intended for coupling to a hook (not shown) on a hoisting crane or any other hoisting means. The block 1 comprises a main block 2 with an associated cover 3, the function of which 1313~
will be explained later. The main block 2 is configurated in its cross-section as a substantially U-shaped part with horizontal legs between which there is formed a recess or opening 4 for accommodating the mechanism locking a cable, rope, band, chain or any other hoisting member. A pair of lugs 5 or the like, attached to the block 2, form fulcra for arms 6,7 which are turnable relative the block. The lugs 5 engage in recesses, not shown in more detail, in the arms 6,7. Since the arms are alike, the description of them will be confined to the right arm in Figure 1.
The arm 7 has an elongate curved configuration in a vertical plane, and is provided with bearing surface 8 in its longitudinal direction. A rope band or similar hoisting member 30 can run freely over the surface 8, which in its transverse direction is defined by projection flanges or the like forming walls on the arm. When the hoisting member is a rope, chain or the like, the bearing surface may have in cross-section a curved shape of any radius of curvature. What is essential is that the hoisting member does not slip out of the arm in case of a skew hoist. It is also conceivable within the scope of the invention to make the surface 8 entirely flat when the hoisting member has the shape of a wide, flat band or belt. The arm 7 can thus form a saddle-shaped support for the rope 30 running between the block 1 and the load.
The end 9 of the arm 7 in the vicinity of the lug 5 is in contact via a shoulder 10 with the inner side 11 of a support 13 associated with a plunger 12. The upper side of the plunger 12, which has a curved configuration, has a bearing surface 14 of approximately the same configuration as that of the bearing surface 8, and which is substantially a continuation of the bearing surface 8 of the respective arm, thus bridging between the bearing surfaces of the two arms. The lower portion of the plunger 12 is provided with downwardly tapering guide lugs 15,16 between which there are arranged conical locking members 17,18 for manually locking the hoisting member. These locking members 17,18 are displaceable to 1313~
and from each other in a horizontal plane with the aid of a bolt 19, not illustrated in more detail. There may be some play between the plunger guide lugs 15,16 and the locking members 17,18, in order to allow the plunger to pivot slightly in a plane radial to the bolt 19. The arms are thus allowed to pivot freely about their respective lugs 5 in mutual independence.
The downwardly tapering shape of the guide lugs and the conical shape of the locking members ensure that the plunger cannot bind against the locking members.
Above the plunger 12 there is a seat 20 movably disposed in the block. The seat downwardly has a concave surface, seen from below, which in its longitudinal direction is provided with an open bearing surface or a groove 21. The surface 21 of the seat 20 forms a common groove together with the plunger bearing surface 14 in which the hoisting member 30 may be locked.
In Figure 2, the groove commonly formed by the bearing surface 14 and the bearing surface 21 serves to accommodate a rope, chain or the like hoisting member. In the case where the latter is a wide band or the like it is obvious that the common groove forms a larger part of the opening or recess 4, defined by the vertical walls of the block and the respective surface on the plunger and seat.
Since the surfaces 14,21 are substantially flat, the entire surfaces of the plunger and seat engage against the band in question.
The seat is upwardly provided with guide lugs 22, which are engaged with the block via compression springs 23 or the like provided recesses 24 formed in the block. The guide lugs 22 may be given any configuration, e.g. a dovetail shape, so that they engage with some play in the upper portion of the block to retain the seat in it. In its longitudinal direction the seat extends to advantage somewhat outside the plunger 12 so that its end groove is above the end grooves of the arms 6,7.
In this way the block may be equipped with plungers of varying dimensions to suit different hoisting 5 1~3~
members. The spacing between plunger and seat should have dimensions such that a heavy chain can also find room. A
cover 3, provided with a plurality of locating bosses 25 tfour in the Figure) or the like, is fitted with fastening means (not shown) securing it to the block with the aid of complementary recesses 26. The cover contributes in distributing more uniformly over the block the forces occurring during hoisting.
Each arm 6,7 may be provided at its outer free end with a stirrup 27 for a hook or the like. The main block may also be formed with a stirrup means 28 for a hoisting hook. Furthermore, each arm may be covered by a casing or the like, fastened to the block for protecting the upper side of the arm and the hoisting member as well as the plunger and seat.
The above~described automatically acting block for locking a hoisting member functions in the following way:-The hoisting member 30 is attached at one or preferably both ends to a load which is to be hoisted, andthe member is allowed to run through the block so that it rests in the channels of the arms 6,7 and the grooves of the plunger 12, at the same time running in the groove commonly formed between th plunger 12 and seat 20. When the block is raised, one or both of the arms 6,7 will pivot under the action of the hoisting member and the load about the lugs 5, the arm 6 turning in a counter-clockwise direction and arm 7 in a clockwise direction in the example illustrated in Figure 1. Whether just one or both arms actuate the plunger locking movement against the seat depends on the position of the block in relation to the hoisting member and also on whether just one or both ends of the hoisting member take up the load. When the block is close to one end of the member, i.e. near the load which is to be lifted, the member will be locked in the block between the plunger and the seat under the action of only one of the arms. In certain cases it may be advantageous to hoist the load in this way. If another 1313~29 position o~ the block in relation to the hoisting member and load is desired the block may be pushed manually along the member, for hoisting once aqain. It is thus essential to the above-described hoisting block that locking of the hoisting member takes place just as effectively with one arm activated or both arms simultaneously. In turn this means that only one of the ends of the hoisting member needs to be fastened to the load.
Via the shoulder 10 of one or both arms the plunger 12 and the section of the hoisting member on it are forced to move upwards against the spring biassed seat 20 so that the member is locked in the groove formed between the plunger and seat.
The groove may advantageously be formed so that it functions as a supplementary lock, e.g. it could be made slightly conical. The load may now be hoisted without fear of the hoisting member slipping.
As already mentioned, in some cases it may be desirable that a load has a certain inclination when it is to be hoisted. In these cases the hoisting block is allowed to run along the hoisting member up to the point where hoisting is performed most advantageously. The block is locked in this position in the same way as described above as soon as one of the hoisting member parts has been stretched. It is also possible to lock the block manually with the locking members 17,18 by moving them towards each other by turning the left- and right-hand threaded bolt 19. The locking members can also act as an extra safety lock working with the automatic lock, 30 the plunger 12 being locked by the locking members 17,18 after having been moved to the position in which it is to be locked. Compression springs 29 may be arranged between the arms 6,7 and the main block 2, whereby the sliding ability of the block along the hoisting member 30 may be regulated.
In connection with Figure 3, an alternative embodiment of the hoisting block is illustrated. This block 3 is also self-adjusting in relation to an optional type of hoisting member, inasmuch as it can be moved to a position best suited to the load hoisted. As distinct from the automatically lockable hoisting block described in connection with Figures 1 and 2 above, this embodiment 5 includes a plunger actuable by a manual locking mechanism 32. In this purely manually lockable block, both arms 34,35 are firmly fixed to the main block 36, thus forming one common unit. Similar to the arms 6,7 the arms 34,35 are provided with elongate bearing surfaces 37,38 si.milar 10 to those described in connection with Figures 1 and 2, for supporting a suitable hoisting member. Similar to the plunger 12, the plunger 33 is formed with a bearing surface 44 for the hoisti.ng member and under the action of the manual locking mechanism 32 it is movable downwards 15 towards a seat 39, this also being provided with a bearing surface 40 similar to the previously described surface 21.
The manually operated locking mechanism comprises two locking members 42, 43, whi.ch are displaceable from and to each other i.n a horizontal plane 20 under the action of a left- and right-hand threaded bolt 41. Locking a hoisting member running freely through the block is achieved manually by the locking members being urged towards each other through the agency of the bolt 41 so that their sloping surfaces press the plunger 33 25 against the seat 39, the member between the plunger and seat thus being securely locked.
In order that the force required to move the piston towards the seat will not be too large when a very heavy load is to be hoisted, the plunger is di.sposed above 30 the seat 39 so that the force transferred from the load to the hoisting member is transferred to the seat and not to the movable plunger. The manual hoisting block otherwise conforms with the automatically acting hoisting block of Figures 1 and 2 with respect to the seat spring 35 suspension, a cover fitable to the main block and the extra stirrup fastenings.
With this block hoisting can also be carried out in any position relative the hoisting member, in turn 131~ r~
resulting in that the load on one arm may greatly differ from the load on the other. It is thus possible with the inventive block to hoist a load fastened only to one part of the hoisting member.
The parts associated with the different blocks, i.e. the plunger, seat and arms, may be manufactured as assemblable sets for different groove dimensions, thus enabling the use of hoisting members having different dimensions. Exchanging such a set merely requires removal of the cover 3 to make the parts accessible. It is also conceivable to arrange several grooves in both plunger and seat, as well as several plunger sections connected to each other in series, i.e. sections of a plunger that are arranged one after the other in the longitudinal direction of the hoisting member, where one or more of the sections may be disposed for actuating the pivotable arms and one section for the manual locking mechanism. By connection in series is also meant here plunger sections arranged one above the other, e.g. for several like or unli~e hoisting members.
It is also possible to arrange plunger sections lying parallel, i.e. arranged side by side transverse the longitudinal direction of the hoisting member. The hoisting block and arms may of course have different dimensions.
The bearing surfaces of the seat 20 and the plunger 12 for the automatically lockable hoisting block as well as the bearing surfaces for the plunger 33 and seat for the manually lockable hoisting block may advantageously be provided with an antislip material to further improve the grip of the plunger and seat on the hoisting member. It is also conceivable to provide the arms with friction-increasing material of suitably restricted areas.
In hoisting blocks of the prior art having automatic locking of a rope running through the block, in which the rope is attached at both ends to a load to be lifted, locking is accomplished by a means associated with the block and turnable in relation to it, this means turning in response to tension in the rope and thus firmly clamping the rope. This type of device is described e.g.
in United States Patent No. 4,097,083. A drawback with the known device is that the block must move along the rope until both parts of the rope have been stretched, in order to achieve locking between rope and block. A
further drawback is that the locking member causes undesirable wear on the rope, with the accompanying risk of rope failure. Furthermore, the locking force ceases as soon as the load in one rope part comes against an obstruction and ceases to weigh down on this part.
Swedish Patent No. 169t695 describes another hoisting block of the self-adjusting tyæe. In this device the lifting means includes a saddle member, which has in cross-section a V-shaped groove in which the lifting rope is intended to run. The shape of the groove causes it to engage against the rope to avoid the rope slipping. This arrangement has the result that the block is very difficult to adjust in relation to the rope, and several adjustments of rope to block will be necessary before hoisting may be performed. Here as well, both rope parts must be loaded for the rope to become locked.
It is an object of the present invention to provide a hoisting block which avoids the above mentioned drawbacks and which, with an automatic and/or manual action, is lockable in an adjustable position in any attitude in relation to the load to be hoisted.
' 1~13~9 The present invention provides a hoisting block, which is lockable and automatically acting in relation to a hoisting member, the block being freely movable along the member, which extends from a load to be moved and to the block, such that the block can assume a desired position in relation to the load, wherein the block includes at least one locking mechanism, the locking mechanism comprising two arms, which are pivotable in relation to the block and mutually independently, the hoisting member being arranged on the arms, at least one plunger actuable by at least one lock mechanism, and a seat disposed in the region of the plunger, a section of the hoisting member running through a groove commonly formed by the plunger and seat, and the section of the hoisting member being lockable between the plunger and the seat by the action of said locking mechanism.
With the present hoisting block, hoisting may also take place even when the load is not in a position of equilibrium, and when the different parts of the hoisting member are unequally loaded. This also means that one of the parts can be completely unloaded during hoisting with the present block.
Embodiments of the present invention will now be described with reference to the accompanying drawings, wherein:-Figure 1 is a schematic elevation of a firstembodiment of the inventive hoisting block, with a front cover removed;
Figure 2 is a cross section through the block of Figure l; and Figure 3 is a schematic elevation of a second embodiment of the hoisting block in accordance with the present invention with the front cover removed.
A first embodiment of an inventive hoisting block is illustrated in Figure 1, the block being intended for coupling to a hook (not shown) on a hoisting crane or any other hoisting means. The block 1 comprises a main block 2 with an associated cover 3, the function of which 1313~
will be explained later. The main block 2 is configurated in its cross-section as a substantially U-shaped part with horizontal legs between which there is formed a recess or opening 4 for accommodating the mechanism locking a cable, rope, band, chain or any other hoisting member. A pair of lugs 5 or the like, attached to the block 2, form fulcra for arms 6,7 which are turnable relative the block. The lugs 5 engage in recesses, not shown in more detail, in the arms 6,7. Since the arms are alike, the description of them will be confined to the right arm in Figure 1.
The arm 7 has an elongate curved configuration in a vertical plane, and is provided with bearing surface 8 in its longitudinal direction. A rope band or similar hoisting member 30 can run freely over the surface 8, which in its transverse direction is defined by projection flanges or the like forming walls on the arm. When the hoisting member is a rope, chain or the like, the bearing surface may have in cross-section a curved shape of any radius of curvature. What is essential is that the hoisting member does not slip out of the arm in case of a skew hoist. It is also conceivable within the scope of the invention to make the surface 8 entirely flat when the hoisting member has the shape of a wide, flat band or belt. The arm 7 can thus form a saddle-shaped support for the rope 30 running between the block 1 and the load.
The end 9 of the arm 7 in the vicinity of the lug 5 is in contact via a shoulder 10 with the inner side 11 of a support 13 associated with a plunger 12. The upper side of the plunger 12, which has a curved configuration, has a bearing surface 14 of approximately the same configuration as that of the bearing surface 8, and which is substantially a continuation of the bearing surface 8 of the respective arm, thus bridging between the bearing surfaces of the two arms. The lower portion of the plunger 12 is provided with downwardly tapering guide lugs 15,16 between which there are arranged conical locking members 17,18 for manually locking the hoisting member. These locking members 17,18 are displaceable to 1313~
and from each other in a horizontal plane with the aid of a bolt 19, not illustrated in more detail. There may be some play between the plunger guide lugs 15,16 and the locking members 17,18, in order to allow the plunger to pivot slightly in a plane radial to the bolt 19. The arms are thus allowed to pivot freely about their respective lugs 5 in mutual independence.
The downwardly tapering shape of the guide lugs and the conical shape of the locking members ensure that the plunger cannot bind against the locking members.
Above the plunger 12 there is a seat 20 movably disposed in the block. The seat downwardly has a concave surface, seen from below, which in its longitudinal direction is provided with an open bearing surface or a groove 21. The surface 21 of the seat 20 forms a common groove together with the plunger bearing surface 14 in which the hoisting member 30 may be locked.
In Figure 2, the groove commonly formed by the bearing surface 14 and the bearing surface 21 serves to accommodate a rope, chain or the like hoisting member. In the case where the latter is a wide band or the like it is obvious that the common groove forms a larger part of the opening or recess 4, defined by the vertical walls of the block and the respective surface on the plunger and seat.
Since the surfaces 14,21 are substantially flat, the entire surfaces of the plunger and seat engage against the band in question.
The seat is upwardly provided with guide lugs 22, which are engaged with the block via compression springs 23 or the like provided recesses 24 formed in the block. The guide lugs 22 may be given any configuration, e.g. a dovetail shape, so that they engage with some play in the upper portion of the block to retain the seat in it. In its longitudinal direction the seat extends to advantage somewhat outside the plunger 12 so that its end groove is above the end grooves of the arms 6,7.
In this way the block may be equipped with plungers of varying dimensions to suit different hoisting 5 1~3~
members. The spacing between plunger and seat should have dimensions such that a heavy chain can also find room. A
cover 3, provided with a plurality of locating bosses 25 tfour in the Figure) or the like, is fitted with fastening means (not shown) securing it to the block with the aid of complementary recesses 26. The cover contributes in distributing more uniformly over the block the forces occurring during hoisting.
Each arm 6,7 may be provided at its outer free end with a stirrup 27 for a hook or the like. The main block may also be formed with a stirrup means 28 for a hoisting hook. Furthermore, each arm may be covered by a casing or the like, fastened to the block for protecting the upper side of the arm and the hoisting member as well as the plunger and seat.
The above~described automatically acting block for locking a hoisting member functions in the following way:-The hoisting member 30 is attached at one or preferably both ends to a load which is to be hoisted, andthe member is allowed to run through the block so that it rests in the channels of the arms 6,7 and the grooves of the plunger 12, at the same time running in the groove commonly formed between th plunger 12 and seat 20. When the block is raised, one or both of the arms 6,7 will pivot under the action of the hoisting member and the load about the lugs 5, the arm 6 turning in a counter-clockwise direction and arm 7 in a clockwise direction in the example illustrated in Figure 1. Whether just one or both arms actuate the plunger locking movement against the seat depends on the position of the block in relation to the hoisting member and also on whether just one or both ends of the hoisting member take up the load. When the block is close to one end of the member, i.e. near the load which is to be lifted, the member will be locked in the block between the plunger and the seat under the action of only one of the arms. In certain cases it may be advantageous to hoist the load in this way. If another 1313~29 position o~ the block in relation to the hoisting member and load is desired the block may be pushed manually along the member, for hoisting once aqain. It is thus essential to the above-described hoisting block that locking of the hoisting member takes place just as effectively with one arm activated or both arms simultaneously. In turn this means that only one of the ends of the hoisting member needs to be fastened to the load.
Via the shoulder 10 of one or both arms the plunger 12 and the section of the hoisting member on it are forced to move upwards against the spring biassed seat 20 so that the member is locked in the groove formed between the plunger and seat.
The groove may advantageously be formed so that it functions as a supplementary lock, e.g. it could be made slightly conical. The load may now be hoisted without fear of the hoisting member slipping.
As already mentioned, in some cases it may be desirable that a load has a certain inclination when it is to be hoisted. In these cases the hoisting block is allowed to run along the hoisting member up to the point where hoisting is performed most advantageously. The block is locked in this position in the same way as described above as soon as one of the hoisting member parts has been stretched. It is also possible to lock the block manually with the locking members 17,18 by moving them towards each other by turning the left- and right-hand threaded bolt 19. The locking members can also act as an extra safety lock working with the automatic lock, 30 the plunger 12 being locked by the locking members 17,18 after having been moved to the position in which it is to be locked. Compression springs 29 may be arranged between the arms 6,7 and the main block 2, whereby the sliding ability of the block along the hoisting member 30 may be regulated.
In connection with Figure 3, an alternative embodiment of the hoisting block is illustrated. This block 3 is also self-adjusting in relation to an optional type of hoisting member, inasmuch as it can be moved to a position best suited to the load hoisted. As distinct from the automatically lockable hoisting block described in connection with Figures 1 and 2 above, this embodiment 5 includes a plunger actuable by a manual locking mechanism 32. In this purely manually lockable block, both arms 34,35 are firmly fixed to the main block 36, thus forming one common unit. Similar to the arms 6,7 the arms 34,35 are provided with elongate bearing surfaces 37,38 si.milar 10 to those described in connection with Figures 1 and 2, for supporting a suitable hoisting member. Similar to the plunger 12, the plunger 33 is formed with a bearing surface 44 for the hoisti.ng member and under the action of the manual locking mechanism 32 it is movable downwards 15 towards a seat 39, this also being provided with a bearing surface 40 similar to the previously described surface 21.
The manually operated locking mechanism comprises two locking members 42, 43, whi.ch are displaceable from and to each other i.n a horizontal plane 20 under the action of a left- and right-hand threaded bolt 41. Locking a hoisting member running freely through the block is achieved manually by the locking members being urged towards each other through the agency of the bolt 41 so that their sloping surfaces press the plunger 33 25 against the seat 39, the member between the plunger and seat thus being securely locked.
In order that the force required to move the piston towards the seat will not be too large when a very heavy load is to be hoisted, the plunger is di.sposed above 30 the seat 39 so that the force transferred from the load to the hoisting member is transferred to the seat and not to the movable plunger. The manual hoisting block otherwise conforms with the automatically acting hoisting block of Figures 1 and 2 with respect to the seat spring 35 suspension, a cover fitable to the main block and the extra stirrup fastenings.
With this block hoisting can also be carried out in any position relative the hoisting member, in turn 131~ r~
resulting in that the load on one arm may greatly differ from the load on the other. It is thus possible with the inventive block to hoist a load fastened only to one part of the hoisting member.
The parts associated with the different blocks, i.e. the plunger, seat and arms, may be manufactured as assemblable sets for different groove dimensions, thus enabling the use of hoisting members having different dimensions. Exchanging such a set merely requires removal of the cover 3 to make the parts accessible. It is also conceivable to arrange several grooves in both plunger and seat, as well as several plunger sections connected to each other in series, i.e. sections of a plunger that are arranged one after the other in the longitudinal direction of the hoisting member, where one or more of the sections may be disposed for actuating the pivotable arms and one section for the manual locking mechanism. By connection in series is also meant here plunger sections arranged one above the other, e.g. for several like or unli~e hoisting members.
It is also possible to arrange plunger sections lying parallel, i.e. arranged side by side transverse the longitudinal direction of the hoisting member. The hoisting block and arms may of course have different dimensions.
The bearing surfaces of the seat 20 and the plunger 12 for the automatically lockable hoisting block as well as the bearing surfaces for the plunger 33 and seat for the manually lockable hoisting block may advantageously be provided with an antislip material to further improve the grip of the plunger and seat on the hoisting member. It is also conceivable to provide the arms with friction-increasing material of suitably restricted areas.
Claims (12)
1. A hoisting block, which is lockable and automatically acting in relation to a hoisting member, said block being freely movable along the member, which extends from a load to be moved and to the block, such that the bock can assume a desired position in relation to the load, wherein the block includes at least one locking mechanism, said locking mechanism comprising two arms, which are pivotable in relation to the block and mutually independently, said hoisting member being arranged on said arms, at least one plunger actuable by at least one lock mechanism, and a seat disposed in the region of the plunger, a section of said hoisting member running through a groove commonly formed by the plunger and seat, and said section of the hoisting member being lockable between said plunger and said seat by the action of said locking mechanism.
2. A block as claimed in claim 1, wherein each arm is elongate and curved and has a convex upper side on which is formed a bearing surface for the hoisting member, the arm having its free end outside the block, and its other end being formed with a recess for pivoting on a lug disposed on the block.
3. A block as claimed in claim 2, wherein said other end of the arm has an abutment with an upper surface suitably formed for the purpose which is in contact with the underside of an extended portion of the plunger.
4. A block as claimed in claim 3, wherein the plunger is disposed in a region between said other ends of the arms, in that the plunger has an upper curved surface with is convex as seen from above, in which there is provided a groove adapted to the hoisting member and oriented such that it constitutes a communicating groove between the bearing surfaces of both arms.
5. A block as claimed in claim 4, wherein the seat has a concave lower surface complementary to the convex surface of the plunger, the former surface being provided with a groove adapted to the hoisting member.
6. A block as claimed in claim 4, wherein on its side facing away from the grooved side the plunger has guide members, between which there is a plunger guide means.
7. A block as claimed in claim 6, wherein the plunger guide means comprises two slopingly cut locking members which are shiftable to and from each other for manual locking of the hoisting member between plunger and seat.
8. A block as claimed in claim 7, wherein each arm is provided with a stirrup means at its free end.
9. A block as claimed in claim 8, comprising a substantially U-shaped part in its transverse direction, this part having horizontal legs, the plunger, seat and/or arms being exchangeably mounted in the region between the legs, which are in mutual force-transferring communication via a cover.
10. A block as claimed in claim 9, provided in its lower horizontal leg with a further stirrup.
11. A block as claimed in claim 1, wherein the plunger comprises plunger sections arranged in series in either the vertical or horizontal direction of the block.
12. A block as claimed in claim 1, 2 or 3, wherein the plunger comprises plunger sections arranged in parallel in the transverse direction of the block.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000553489A CA1313529C (en) | 1987-12-03 | 1987-12-03 | Automatically acting, lockable hoisting block |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000553489A CA1313529C (en) | 1987-12-03 | 1987-12-03 | Automatically acting, lockable hoisting block |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1313529C true CA1313529C (en) | 1993-02-09 |
Family
ID=4136997
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000553489A Expired - Fee Related CA1313529C (en) | 1987-12-03 | 1987-12-03 | Automatically acting, lockable hoisting block |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1313529C (en) |
-
1987
- 1987-12-03 CA CA000553489A patent/CA1313529C/en not_active Expired - Fee Related
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4128267A (en) | Lifting beam | |
| US5035336A (en) | Compact collapsible manhole cover lifter | |
| US4605189A (en) | Anti-fail device for locking a drawing-board pillar against motion | |
| US4118010A (en) | Multi-purpose lifting and mounting assembly | |
| US4728138A (en) | Automatically acting, lockable hoisting block | |
| US2356147A (en) | Self-equalizing sling | |
| CA1060503A (en) | Engine lift tool | |
| US5971363A (en) | Tree winch mounting system | |
| US3033605A (en) | Expansion-type grapple for lifting and carrying loads | |
| US4225012A (en) | Safety clamp device and apparatus utilizing same | |
| US4422556A (en) | Receptacles for overhead storage systems | |
| CA1313529C (en) | Automatically acting, lockable hoisting block | |
| US4181194A (en) | Safety clamp device and apparatus utilizing same | |
| US4251099A (en) | Automatic release device for lifting slings | |
| EP0160021B1 (en) | A device for lifting and handling objects | |
| US4579235A (en) | Crane boom stowing apparatus | |
| US4790049A (en) | Rope locking device | |
| US4097083A (en) | Adjustable lifting thimble | |
| EP0615021A1 (en) | Lifting device | |
| JP3184665B2 (en) | Concrete product lifting equipment | |
| CA2193580A1 (en) | Hanger for lift truck fork | |
| US3186752A (en) | Lifter with substantially constant inward jaw pressure | |
| US3879078A (en) | Self-locking lifting mechanism | |
| GB2030253A (en) | Submarine pipe line alignment rig | |
| US3120898A (en) | Device for handling logs and the like |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |