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Patent Searching and Data


Title:
CLAMPS
Document Type and Number:
WIPO Patent Application WO/1995/010389
Kind Code:
A1
Abstract:
A top jaw (42) is able to provide course adjustment with a bottom jaw (43) enabling a firm grip on a bar (10) attached to the side of an operating table to be achieved. To effect the course adjustment, a lever (46) is pivoted to the right, when viewed in the figure, to remove a pin (47) from a cooperating socket (48). The lever (46) is then turned. A block (54) is connected to the part that turns with the lever (46) about an offset axis. Accordingly, the block (54) can slide from side to side relative to the jaw (42). However, upwards or downwards movement of the block (54) is passed onto the block (54). When the desired course adjustment has been effected, the pin (47) is returned to a different socket (48). Final adjustment is achieved by pivoting a lever (56) which is also connected about an offset axis to a block that can slide from side to side relative to the jaw (43) but is caused to move with the jaw (43) in an up and down direction. Instruments are connected to the clamp through channels in the clamp housing (now shown in the figure).

Inventors:
Moran
Peter, Pierce
Sam
Application Number:
PCT/GB1994/002175
Publication Date:
April 20, 1995
Filing Date:
October 06, 1994
Export Citation:
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Assignee:
SURGICAL INNOVATIONS LIMITED MORAN
Peter, Pierce
Sam
International Classes:
A61G13/10; B23Q1/28; (IPC1-7): B23Q1/28; A61G13/10
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Claims:
CLAIMS
1. A clamp arranged, in use, to be fixed in position relative to an operating table and to provide a support for items located above the table, the clamp comprising a pair of relatively moveable jaws moveable from a first position in which they can be brought to a location in which they can be fixed in position relative to an operating table to a second position in which they are fixed in position relative to the table.
2. A clamp as claimed in claim 1 in which the clamp is arranged to be clamped onto an operating table in the second position.
3. A clamp as claimed in claim 1 or 2 in which relative movement of the jaws is effected by causing movement of at least one control member.
4. A clamp as claimed in claim 3 in which the relative movement of the jaws in at least one direction is effected by causing movement of at least one control member in a direction transverse to the direction of relative movement of the jaws.
5. A clamp as claimed in claim 3 in which the relative movement from the first to the second position is effected by causing pivotal movement of the control member.
6. A clamp as claimed in claim 5 in which the pivotal movement of the control member is arranged to be about an axis transverse to the direction of relative movement effected between the jaws.
7. A clamp as claimed in any of claims 3 or 4 to 6 in which, in the second position, the control member is in a neutral or over centre position in which the internal forces between the clamp and a table to which the clamp is, in use, attached, do not exert a force such as to tend to move the control member to a position in which the jaws can be moved towards the first position.
8. A clamp as claimed in any of claims 3 to 7 in which a control member is arranged act on at least one of the jaws to cause relative movement of the jaws from the first to the second position and from the second to the first position.
9. A clamp as claimed in any of claims 3 to 8 in which the control member includes an intermediate member moveable relative to the operating member and a jaw and arranged to cooperate with the jaw and to slide relative to the jaw in a direction transverse to the movement of the jaw.
10. A clamp as claimed in claim 9 in which the sliding movement is in a translational direction.
11. A clamp as claimed in claim 9 or 10 in which the control member exerts a mechanical advantage whereby at least a part of the control member is arranged to travel through a greater distance than the resulting relative movement of the jaws.
12. A clamp as claimed in any of claims 3 to 11 in which the control member comprises adjustment means arranged to be able to alter the distance between the jaws whereby the jaws can be at a different relative spacing when in the second position.
13. A clamp as claimed in claim 12 in which the adjustment means comprises a jaw being releasably retained in one of a plurality of positions relative to the other jaw.
14. A clamp as claimed in claim 13 in which the releasable retention is effected by retaining an operating member in one of a plurality of positions.
15. A clamp as claimed in any preceding claim including biasing means arranged to exert a force on at least one of the jaws when in the second position to urge relative movement of the jaws to the first position.
16. A clamp as claimed in any preceding claim in which both jaws are capable of movement relative to another part of the clamp.
17. A clamp as claimed in claim 16 in which both jaws are capable of sliding movement relative to another part of the clamp.
18. A clamp as claimed in any preceding claim including a cam arranged to act on at least one of the jaws.
19. A clamp as claimed in any of claims 3 to 14 including a flexible member arranged to act between the control member and at least one of the jaws.
20. A clamp as claimed in claim 19 including means for altering the effective length of the flexible member.
21. A clamp as claimed in any preceding claim including two means for enabling support to be provided for items located above a table.
22. A clamp as claimed in any preceding claim in which the means for enabling support to be provided for items located above a table comprises a socket.
23. A method of fixing a clamp in position relative to an operating table comprising moving two jaws of a said clamp relative to each other to attach the clamp to a support whereby the clamp is fixed in position relative to the table.
24. A method as claimed in claim 23 comprising fixing the clamp to a support provided by the table.
25. A method as claimed in claim 23 or 24 comprising moving the jaws by operating a control member.
26. A method as claimed in any of claims 22 to 24 comprising first adjusting the clamp before the two jaws the clamp are moved relative to each other to attach the clamp to the support.
27. A method as claimed in claim 26 when dependent upon claim 25 comprising effecting the first adjustment in order that the control member can move to the same end position to effect the attachment with the jaws being able to be at different relative positions.
28. A method as claimed in any of claims 23 to 27 when fixing a clamp as claimed in any of claims 1 to 22.
Description:
CLAMPS

The present invention relates to a clamp and to a method of fixing a clamp. The invention is particularly, although not exclusively applicable to clamps, that are attached to the sides of operating tables and that have bars extending upwardly therefrom for the attachment of instruments such as retractors being used in endoscopic surgery.

According to a first aspect of the present invention a clamp is arranged, in use, to be fixed in position relative to an operating table and to provide a support for items located above the table, the clamp comprising a pair of relatively movable jaws movable from a first position in which they can be brought to a location in which they can be fixed in position relative to an operating table to a second position in which they are fixed in position relative to the table.

The relative movement from the first to the second position may be effected by causing movement of one or two control members. Relative movement of the jaws in at least one direction may be effected by causing movement of the or each control member in a direction transverse to the direction of relative movement of the or each jaw or, alternatively or additionally, by causing pivotal movement of the control member. The pivotal movement of the control member may be arranged to be about an axis transverse to or perpendicular to the direction of relative movement effected between the jaws.

The clamp may be arranged to be clamped onto the operating table in the second position.

In the second position the control member may be in a neutral or overcentre position in which the internal forces between the clamp and a table to which the clamp is, in use, attached do not exert a force tending to move the control member to a position in which the jaws can be moved towards the first position.

The control member may be arranged to act on at least one of the jaws to cause relative movement of the jaws from the first to the second position and from the second to the first position.

The clamp may include biasing means arranged to exert a force on at least one of the jaws when in the second position to urge relative movement of the jaws to the first position.

Both jaws may be capable of movement relative to another part of the clamp and both jaws may be capable of sliding movement relative to another part of the clamp.

The clamp may include adjustment means arranged to be able to alter the distance between the jaws whereby the jaws can be at a different relative spacing when in the second position to enable the clamp to be attached to differently configured or dimensioned supports.

The adjustment means may comprise a jaw being releasably retained in one of a plurality of positions relative to the other jaw. The releasable retention may be effected by retaining an operating member in one of a plurality of positions, for instance by locating a locking member in one of a plurality of openings.

The adjustment means may include an intermediate member movable relative to the operating member and a jaw arranged to cooperate with the jaw and to slide relative to the jaw in a direction transverse to the movement of the jaw. The sliding movement may be arranged to ' be in a translational direction.

The control member may exert a mechanical advantage whereby at least a part of the control member is arranged to travel through a greater distance than the resulting relative movement of the jaws.

The clamp may include a cam arranged to act on at least one of the jaws.

The clamp may include a link arranged to act between the control member and at least one of the jaws.

The clamp may include a flexible member arranged to act between the control member and at least one of the jaws. The clamp may include means for altering the effective length of the flexible member.

The clamp may include a pivot axis which may be offset from a pivot axis of the control member whereby relative movement of the pivot axes to each other effects the relative movement of the jaws.

The clamp may include two means for enabling support to be provided for items located above the table. One or both of those means may comprise attachment means for a bar which attachment means may comprise a socket or sockets on the clamp.

According to another aspect of the present invention a method of fixing a clamp in position relative to an operating table comprises moving two jaws of the clamp relative to each other to attach the clamp to a support whereby the clamp is fixed in position relative to the table.

The method may comprise fixing the clamp to a support provided by the table.

The method may comprise moving the jaws by operating a control member.

The method may comprise first adjusting the clamp, for instance by altering the spacing between the jaws, in order to enable the clamp to be attached to differently configured supports. The method may comprise effecting that first adjustment in order that a control member can move to the same end position to effect the attachment with the jaws being able to be at different relative positions.

The present invention includes any combination of the herein referred to features and limitations.

The invention may be carried into practice in various ways but several embodiments will now be described, by way of example and with reference to the accompanying drawings, in which:-

Figure 1 is a side view of a clamp according to a first aspect of the present invention;

Figure 2 is a front view with part of an operating handle omitted;

Figure 3 is a plan view with the operating handle omitted;

Figure 4 is a schematic perspective view from the rear of the second embodiment of a clamp;

Figure 5 is a schematic perspective view from the front of the clamp shown in Figure 4 with part of the clamp missing;

Figure 6 is a front view of the clamp with an operating handle in a closed position;

Figure 7 is a view similar to Figure 6 with the operating handle in an open position;

Figure 8 is a schematic perspective view from the front of a third embodiment of the clamp;

Figure 9 is an exploded view of the parts shown in Figure 8 ;

Figure 10 is a side sectional view of another embodiment of a clamp similar to that shown in Figures 1 to 3;

Figures 11A, 11B, 12A, 12B, 13A and 13B are rear and side views of the clamp of Figure 10 showing the jaws in the start position in Figures 11A and 11B, an intermediate position in Figures 12A and 12B and the locked position in

Figures 13A and 13B;

Figure 14 is an exploded view of the operative parts of the clamp shown in Figure 10 that effect the movement of the jaws;

Figure 15 is a side sectional view showing the operating handle that effects movement of the upper jaws; and

Figures 16, 17 and 18 are front, rear and plan views of the clamp body shown in Figure 10.

The clamps shown in the drawings are all arranged to be attached to a side bar 10 that surrounds the sides of an operating table. Such a side bar is shown in cross- section in Figure 1. Side bars are not uniform either in their height, when viewed in cross-section or in their width. Accordingly, rather than have separate sized clamps associated with each different height of side bar and with each different width of side bar it is desirable to have one clamp that will fit all heights and widths of side bar within certain limits. Furthermore, the clamps are required to be fitted over operating sheets that over¬ lie a patient for hygiene reasons. These sheets extend down over the sides of an operating table and over the side bars. There may be one, two or three or more layers of sheet overlying the side bar which will have a significant effect on the effective width and depth which the clamp has to be attached to. It is desirable to have one clamp that can have a very firm grip on the side bar whether that clamp has to grip through no layers at all, or several layers of sheet.

The clamp 11 shown in Figures 1, 2 and 3 includes a housing 12. When the clamp 11 is attached to the side bar, two upwardly extending rods may project from passages 13 at either side of the housing. The rods can be held in the passages 13 by tightening a threaded bolt extending through a threaded side wall (not shown) in the housing 12 leading to the passages 13 to bear against the rods.

Surgical instruments can then be attached to each of the rods at a region located above the table. The passages 13 are also shown in Figures 17 and 18) .

The clamp includes a top jaw 14 and a bottom jaw 15. These jaws, on their gripping surfaces, taper downwardly and inwardly and upwardly and inwardly respectively towards the side of the operating table such that when they are brought together they urge the clamp against the side of the table or against the side of the side bar 10.

The jaw 14 is mounted on the housing 12 such that it can move towards or away from the lower jaw 15 upon operation of a threaded nut 16. The nut 16 extends down through a threaded recess provided in an overhanging flange 17 that is secured to the top of the housing 12. As the nut 16 is tightened downwardly it bears against an upwardly facing surface of the top jaw 14 to push it down. The top jaw 14 is constrained to slide within the housing by the cooperating slide surfaces 18 and 19 of the jaw and housing respectively. The lower jaw 15 is also guided by cooperating guide surfaces aligned with those of the top jaw and housing.

Movement of the lower jaw along its guide surfaces is controlled by an operating handle 20. A shaft 21 of the operating handle 20 is rotatably mounted on the housing and a cam 22 is constrained to rotate with the shaft 21 by a key 23 (shown in Figure 2) . The cam 22 cooperates with the downwardly facing surface of the jaw immediately adjacent to its gripping surface and also with an upwardly facing surface 24 integral or fast with the jaw 15 but located beneath the shaft 21. Movement of the operating handle in one direction causes the lower part of the cam to bear against the surface 24 to move the jaw downwardly

and movement in the opposed direction causes the cam to bear against the jaw 15 just beneath its gripping surface to move the jaw upwardly into engagement with the side bar 10.

The significant mechanical advantage afforded by the cam allows a very large force to be applied to the jaw 15 to bias it towards the jaw 14 and provides a very secure clamp on the side bar 10. If desired, the cam 22 can have a locking position, as shown in Figure 2, where the angle is rotated such that the jaw 15 is at the uppermost possible limit of its travel.

The jaws 14 and 15 are biased away from each other by springs 25 to bias the jaw 14 upwardly such that, when the nut 16 is adjusted to move it upwardly through the overhanging flange 17 the jaw 14 is able to move upwardly, away from the jaw 15.

In Figures 4 to 7 like parts to those shown in Figures 1 to 3 have been given the same reference numeral. The housing 12 again incorporates two passages 13 for rods to project upwardly above the table and to have instruments secured thereto. A threaded locking bolt 26 to secure rods within the passages 13 is shown.

In the embodiment shown in Figures 4 to 7 the top jaw 14 is integral with the housing 12. The bottom jaw 15 is guided for a sliding movement up and down within the housing 12 by cooperating slide surfaces (not shown) . The lower jaw 15 is biased away from the upper jaw 14 by springs 25 and the lower jaw 15 is able to be pulled upwardly towards the jaw 14 by a cable 27. That cable extends upwardly past the jaw 14 and over a fixed arcuate surface 28 just beyond which it is connected to a threaded

shaft 29. The shaft 29 is connected to an axially fixed rotatable threaded knob 30 which is mounted in a handle 31. The handle 31 is pivotally mounted on the housing 12 about an axis 32.

As the axis 32 is located at a higher elevation than the arcuate surface 28 and is displaced in the vertical direction, when the handle is brought from the position shown in Figure 4 where it extends upwardly and away from the table towards the position shown in Figure 6 where it extends downwardly and substantially in line with the side of the table the shaft 29 is caused to pull the cable 27 over the arcuate surface 28 thereby pulling the jaw 15 upwardly with a considerable mechanical advantage to firmly clamp the side bar of a table between the jaws.

In the position shown in Figure 6, the reactive downwards force that the lower jaw imparts upon the cable 27 acts to exert a clockwise force about the axis 32 as does the force between the handle 31 and the region where the force is transmitted to that handle from the cable as the handle passes through an "overcentre" position about the surface 28 to ensure that the handle 31 is held in position.

Adjustment of the clamp to enable the clamp to be attached to different width and depths of side bar and to cope with differing layers of sheets between the jaws and the side bar is enabled by rotating the knob 30 to alter the effective length of the cable between the handle and the lower jaw.

In the embodiment, shown in Figures 9 and 10 like parts with those in the other figures have been given the same reference numeral. The housing 12 includes two

upwardly extending passages 13 at either side for rods, as described above. Locking bolts 26 can extend through threaded openings in the side walls leading to the passages 13 to hold the rods in place.

The top jaw 14 is integral with the housing 12 and the bottom jaw 9 is arranged to slide in an up and down direction through parallel slots 33 formed in the housing. The bottom jaw 15 also includes a guide surface 19 to cooperate with a corresponding surface of the housing to guide the up and down movement. Similar adjustment means to that provided by the overhanging flange 17 and the nut 16 shown in Figures 1 to 3 are provided but are not shown.

A shaft 34 is pivotally connected to the housing about an axis 35 via the openings 40 in the housing. Stub shafts 36, which are offset from the axis 35, are each pivotally connected to a different operating lever 37. The lower end of each of these operating levers 37 is pivotally connected to the lower jaw 15 by stub axles 38.

The operating handle 31 is fixed to the shaft 34 by a threaded bolt 39.

The handle 31 is shown, in Figure 8, in the locked position. Movement of the handle in an outwards and upwards direction from that shown in Figure 8 causes the shaft 34 to rotate about the axis 35. As rotation occurs about the axis 35 the stub shafts 36 are caused to move about the axis 35 in a downwards direction, and also inwardly towards the housing. As the stub shafts 36 move downwardly they force the operating levers 37 to move downwardly which in turn force the lower jaw 15 to slide downwardly to open the space between the jaws and allow

- li ¬ the clamps to be removed from the side bar. Attachment of the clamp is a reversal of that process.

It can be seen from the drawings that the line viewed from the side of the clamp between the stub shafts 36, the axis 35 and the stub axles 38 goes through an overcentre position or into a neutral position when the handle 31 is in the locked position shown in Figure 8 thereby preventing internal forces of the clamp being able to effect any loss of grip of the clamp on the bar.

The clamp 41 shown in Figures 10 to 18 is similar to the clamp shown in Figures 1 to 3 in that a movable top jaw 42 and bottom jaw 43 taper downwardly and inwardly and upwardly and inwardly respectively towards the side of the operating table such that when they are brought together they urge the clamp against the side of the table or against the side of the bar 10.

Both of the jaws 42 and 43 are guided on the clamp housing 44 by correspondingly tapered surfaces sliding along the rear of the clamp and within the tapered surfaces 45 shown in Figure 18.

In use, the top jaw 42 is moved first to effect the coarse adjustment so suit the size of the bar 10 and the thickness of the operating sheets. Movement of the jaw is effected by rotational movement of the lever 46 and that movement causes the jaw 42 to move from the position shown in Figures 11A and 11B to the position shown in Figures 13A and 13B via the position shown in Figures 12A and 12B.

The lever 46 is normally rotationally fixed by a pin

47 on the lever being located in one of seven holes 48 on the front of the housing as shown in Figure 16. The pin

46 can be moved out of the hole 48 by pivoting the lever about a shaft 49 against the action of a spring 50, as shown in Figure 15. The lever can then be rotated with the cylindrical surface 51 of the lever rotating in a correspondingly shaped bearing surface 52 in the housing, as shown in Figure 16. As the lever rotates about the axis that is fixed relative to the housing a projecting cylindrical bush 53 connected eccentrically relatively to that axis is caused to move through an arc. The bush 53 extends through an opening in a rectangular drive block 54 and that block is located in an opening 55 in the top jaw that permits lateral movement of the block relative to the top jaw but prevents relative up or down movement. Accordingly as the lever rotates and the bush 53 moves through an arc the block slides towards one side of the opening in the jaw and moves the top jaw downwardly.

When the desired coarse adjustment of the top jaw has been effected the lever is released such that the spring urges the pin 47 back into a different locking hole 48 in the housing.

The clamp is then brought against the side of the table or against the side of the bar 10 (if it is not already there) and the lower jaw 43 is moved upwardly to attach the clamp. The lower jaw 43 is moved upwardly by turning the operating handle 56 as described above in relation to the handle 46 and the jaw 42 with the exception that when the jaw is clamped it is retained in a particular position by virtue of the friction in the parts connecting the handle and the jaw.