FIELD OF INVENTION

The present invention is concerned with a support system and, more particularly, with a support system including an adjustable arm.

BACKGROUND ART

It is necessary in any number of tasks to position an adjustable arm and then lock it into place to support an article. Typically, an adjustable arm consists of a plurality of arm sections disposed in end to end relation with adjacent arm sections interconnected for angular movement therebetween about at least one axis. To lock the arm sections agains angular movement conventional adjustable arms are provided with a locking mechanism at each join between adjacent arm sections. However, such an arrangement has a disadvantage in that it is necessary to operate the locking mechanisms individually to lock the arm in the desired position and to release the arm to allow for further adjustment of the arm sections. This may be a time consuming and tedious operation, especially if adjustments to the arms position are required to be carried out regularly.

United States Patent No. 3,278,207 describes an improved adjustable arm having at least three joints which can be locked and unlocked simultaneously by a single movement, the structure involving at least one split ball joint.

An adjustable arm having a knuckle joint at one end and a ball and socket joint at the other end of each section is described in United States Patent No. 4,531,855 which is

incorporated herein by reference. A push rod extends axial--Y through the section with each end of the rod bearing against one of the components of the adjacent joint. A compressive force is applied to the push rod by rotating a collar forming a part of the socket so that the ball moves further into the socket and thus the push rod moves relatively away from the socket and abuts a component of the adjacent joint.

Another improved adjustable arm is described in United States Patent No. 4,767,231 (which is incorporated herein by reference), the arm utilising a ball and socket joint with a locking member slidably mounted in a recess in the ball so that one end projects from the ball and bears against the socket. To lock the arm a compressive force is applied to the locking member by means of a compression member which is simply a thumb-screw which forces a push rod to move against a concave cup within the socket which forces the ball against the swaged edge of the socket.

DISCLOSURE OF THE INVENTION

Accordingly, in one broad aspect the invention resides in a support system comprising an adjustable arm having a plurality of sections join together by a ball and socket joint, the adjustable arm being of the type where a compressive force is applied to a ball and socket joint to lock all joints against relative movement, and a locking assembly comprising a first push rod slidably mounted in a housing, the first push rod acting to apply said compressive force, and control means including a lever that is pivotably mounted within said housing, said lever having an arcuate

camming surface so made and arranged that pivotal motion of said lever about its pivot point urges the arcuate camming surface into abutment with the first push rod thereby urging the first push rod to slide within said housing whereupon said compressive force is applied.

In a preferred embodiment of the invention each section of the adjustable arm comprises a housing, a ball retained within the housing, a concave cup slidably mounted within the housing with clearance between the cup and the ball, a locking member slidably mounted in a recess in the ball so that one end projects beyond the ball and bears against the concave face of the cup, a third push rod passing through the section so that one end bears against the cup adjacent one end of the section and the other end bears against the locking member of the joint adjacent the other end of the section, the first push rod applying a compressive force to the third push rod to simultaneously lock all joints against relative movement. Alternately, a second push rod as described below may apply the compressive force.

In a further broad aspect the invention resides in a locking arrangement comprising a locking assembly for an adjustable arm having a plurality of sections joined together by a ball and socket joint, the adjustable arm being of the type where a compressive force is applied to a ball and socket joint to lock all joints against relative movement, comprising a first push rod slidably mounted in a guide frame, the first push rod acting to apply said compressive force, and control means including a lever that is pivotably

mounted on said guide frame, said lever having an arcuate camming surface so made and arranged that pivotal motion of said lever about its pivot point urges the arcuate camming surface into abutment with the first push rod thereby causing the first push rod to slide within said guide frame whereupon said compressive force is applied.

Preferably, the arcuate camming surface includes a roller which is urged into abutment with the first push rod. The roller is provided to allow the lever to pivot readily and is recessed in the arcuate camming surface but protrudes sufficiently to abut the first push rod.

The pivotal motion of said lever can be controlled manually or by remote operation. In the former case, said lever protrudes from said housing and acts as a handle, the pivotal motion of said lever being induced by moving said handle. In the latter case, pivotal motion of said lever is induced by the operation of a control system that is remote from the locking arrangement and the control system is mechanically or electromechanically linked to said lever or the pivotal motion of said lever is controlled hydraulically or with compressed gas. It is preferred that the linkage is a cable system linking a foot pedal, hand grip or the like to said lever.

In a preferred embodiment of the invention, said guide frame includes a thumb-screw arrangement adapted to abut said lever to provide means for adjusting position of said lever.

In a further preferred embodiment of the invention, the first push rod applies said compressive force to an elongated

member extending through a clamp member in a plane transverse to the plane of the first push rod, thereby clamping said clamp member to said elongated member, said clamp member including a compression member co-axially aligned with the first push rod whereby said compressive force is transferred through said elongated member to the compression member. Preferably the compression member applies said compressive force to a ball and socket joint in the adjustable arm.

In a further broad aspect there is provided a clamp for securing a first elongated member in fixed relationship with a support member comprising a frame with a projection extending outwardly from one side thereof constituting a first clamping surface and a moveable member mounted on said one side constituting a second clamping surface, the distance between the first and second clamping surface being variable by moving said moveable member; locking means associated with said moveable member so that a selected distance between the first and second clamping surfaces can be maintained, the distance being selected so as to securely fix the frame to the support member and clamp means for supporting said first elongated member mounted on said frame.

Preferably, said moveable member is a rotatable member which rotates eccentrically about its axis of rotation, the distance between the first and second clamping surfaces being variable by rotating the rotatable member. Most preferably, the rotatable member has a substantially circular cross- section and its axis of rotation is located away from the centre so that it rotates eccentrically about that axis, the

rotatable member optionally including a flattened portion on its periphery to facilitate attachment of the clamp to the support member.

Advantageously, the support member is a second elongated member such as a bar which extends along the edge of a object. The object may be a table, such as an operating table, a bench, wall or the like.

In a preferred form of the invention, the clamp means comprises a spigot extending through an opening in said frame from said one side to the other side, the spigot having an opening adapted to receive the first elongated member extending transversely therethrough, the spigot further including screw means for clampingly engaging said first elongated member. The clamp means may additionally comprise a collar of circular cross-section adapted to releasably engage said frame which encircles the spigot the collar being rotatable about the spigot when released from engagement with the frame, the collar including a plurality of cut out portions in communication with the opening at the top of the collar around its circumference, the collar partially overlying the opening in the spigot so that the shape of the cut out portion lying at top and bottom of the collar at the selected degree of rotation modifies the shape of the opening in the spigot so that it fits tightly around a first elongated member of predetermined cross-section. Advantageously, the collar and said frame have complementary teeth formed thereon which are meshed together when the collar engages said frame. This provides positive angular

positioning of the collar.

In a further broad aspect of the invention there is provided a support system in which a clamp as described above is used to support an elongated member, preferably in a vertical orientation, on which is mounted an adjustable arm.

In a still further broad aspect of the invention there is provided a pivotable support for securing and positioning an implement, said support comprising a frame member so made and arranged that is partially encircles an implement- receiving member of generally spherical shape with a bore therethrough in which said implement is received, said frame member including opposed cup members rotatably secured thereto between which said implement-receiving member is mounted in a freely rotatable disposition, at least one cup member being moveable towards and away from the opposing cup member so that said implement-receiving member is removably secured therebetween, said one cup member being moveable into a position such that rotation of said implement-receiving member is prevented.

So as to reduce the complexity of the apparatus generally only one cup member is moveable towards the opposing cup member. In this case, said one cup member is adapted to receive the end of a screw the screw-threaded portion of which engages a first threaded bore through said frame member, the screw including a first spigot attached to the end of the screw-threaded portion said one cup member being freely rotatable on the spigot, whereby turning the screw causes said one cup member to move towards or away from

the opposing cup member.

It is a further preferred that said implement-receiving member is made of a resilient material and includes a mouth opening to said bore, the mouth being slightly narrower than said bore so that said implement can be pushed into said bore through the mouth and retained in said bore. This allows any implement of suitable size or having a portion thereof of suitable size of be snapped into the pivotable support.

The pivotable support may be secured to a mounting arm in which case said frame member includes a second threaded bore adapted to engage a threaded portion of the mounting arm. Preferably, said implement-receiving member has a shallow cavity in its surface that is adapted to receive a second spigot attached to a threaded portion of a mounting arm to prevent excessive rotation of said implement-receiving member. This prevents the implement-receiving member being turned so that the mouth comes around past the end of the frame member thus causing the implement-receiving member to fall out. If it is desired to remove the implement-receiving member the mounting arm need only be unscrewed a little so that the second spigot no longer engages the shallow cavity. This allows an implement-receiving member which is adapted, for example by having a bore of a different diameter or shape, to receive a different implement to be inserted.

The second spigot also serves to space the implement- receiving member from said frame-member to isolate it. In this case it is preferred that the implement-receiving member be made of a dielectric material. The pivotable support is

thus adapted to prevent the flow of electricity therethrough, which is advantageous, for example, in surgical use.

The mounting arm can be an adjustable arm thus the present invention further provides for a support system as described above including a pivotable support mounted on an adjustable arm.

In a still further broad aspect of the invention there is provided a sling for immobilizing the arm of surgical patient comprising a hollow elongated member adapted to be secured to a mounting arm, said hollow elongated member having an opening at one end and a slide member slidably mounted in its interior with a spring disposed between said slide member and said one end, said slide member having a sling member attached thereto, the sling member extending through the opening in said one end and having a loop formed therein outside said elongated member, whereby the loop is secured to the arm of a surgical patient preventing movement of the arm except when the arm goes into spasm.

The sling can be mounted on an adjustable arm as described above thus the present invention further provides a support system including a sling mounted on an adjustable arm or in a pivotable support mounted on an adjustable arm.

Various other implements can be mounted on an adjustable arm thus the present invention further provides a system for mounting any implement on adjustable arm as described above. Preferably, said implement is a pulley, clamp, gauge, mirror, camera, optical device, light bulb, surgical implement, tool, microphone or the like.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more readily understood reference will now be made to the accompanying drawings in whic :-

Fig. 1 is a perspective view of a support system in accordance with the present invention;

Figs. 2A and 2B are cross-sections through the locking assembly shown in Fig. 1;

Fig. 3 is a cross-section through the terminal ball and socket joint in the adjustable arm shown in Fig. 1;

Fig. 4 is a perspective view of a clamp in accordance with the present invention;

Fig. 5 is an exploded view of the clamp in Fig. 4; Fig. 6 is a perspective view of a pivotable support in accordance with the present invention;

Fig. 7 is an exploded view of the pivotable support shown in Fig. 6;

Fig. 8 is a perspective view of a sling in accordance with the present invention;

Fig. 9 is a cross-section through the sling shown in Fig. 8; and

Fig. 10 is a perspective view of a spacer member in accordance with the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now to Fig. 1, it may be seen that the support system includes an adjustable arm 11 and a locking assembly 12. In this case the arm 11 is mounted on an elongated member, which is in fact a post 13 secured by a

clamp, and has a pivotable support 14 holding an article 15 attached at its end.

The locking assembly 12 includes a lever 16 protruding from a guide frame, in this case housing 17, and connected to cable 18. Brace 19 acts to support the cable 18 which is a push-pull Bowden cable. The locking assembly further includes thumb-screw 20. The housing 17 is attached to clamp member 21 and to socket 22 whereby the adjustable arm 11 is secured to post 13 and is placed under the control of locking assembly 12 as will now be described with reference to Fig. 2 where Fig. 2A shows the locking assembly in the unlocked position and Fig. 2B shows it fully locked.

In operation, lever 16 is pivotable under the remote control of a foot pedal, hand grip or similar device or by using it as a handle and squeezing lever 16 and brace 19, thus causing lever 16 to pivot about pivot 23. It is a feature of the lever 16 that it has a flattened portion 24 in the vicinity of pivot 23 and this flattened portion has arcuate camming surfaces 25 which abut push rod 26 and thumbscrew 20 when the lever 16 is pivoted into the locking position (as shown in Fig. 2B) . The camming surfaces 25 includes rollers 27 which bear on the abutting surface of push rod 26 and thumbscrew 20 respectively and facilitate pivotal movement of the lever 16. When the camming surface 25 adjacent push rod 26 is in abutment therewith, the push rod is urged to slide in the direction of arrow A. When the lever 16 is allowed to pivot in the reverse direction to its original position the camming surface 25 no longer abuts the

push rod 26 and the compressive force on said push rod is removed. It may be noted with reference to Fig. 2B that when the rollers 27 rotate past the pivot 23 that the bottom of the flattened portion 24 abuts the housing 17. This prevents further rotation which would otherwise bring the arcuate camming surface 25 out of abutment with push rod 26 and release the compressive force.

The purpose of thumb-screw 20 is to adjust the position of lever 16 so that pivotal motion of said lever causes it to abut the push rod 26 with sufficient force to cause it to slide.

Push rod 26 transmits the compressive force directly to an adjustable arm or, as in this case, indirectly to the arm via clamp member 21. Here the post 13 is held between push rod 26 and compression member 28, and movement of push rod 26 in the direction of arrow A causes the post 13 and compression member 28 also to move in this direction (as post 13 is fixed clamp member 21 actually moves in the opposite direction but there is relative movement of the post in the direction of arrow A) . Since the post 13 is sandwiched between push rod 26 and compression member 28 it is firmly held when compression is applied, thus the application of a compressive force clamps the adjustable arm 11 to post 13.

Referring to Fig. 3, compression member 28 is slidably mounted in housing 22 and includes an elongate portion and a concave cup. Sliding movement of the compression member 28 causes locking member 30 to move against ball 33, closing the gap 31, and jamming the ball against the edge 32 of the

socket thereby locking the joint. A compression rod 34 is slidably mounted in the next section of the arm with one end bearing against the inner end of the locking member 30 in the joint and the other end bearing against a concave cup in the next joint. Thus, a compressive force applied by compression member 28 is in turn transferred to locking member 30 and then to the compression rod 34 whereupon the force is transferred to the next ball joint, thus locking all the ball joints against relative movement with controllable friction between the ball and the socket in each joint. Preferably, the ends 32 of the socket are turned inwardly and the ball 33 is not entirely spherical so that the ball is retained in the housing 22. The adjustable arm can also be of the type including elbow joints. Electrical leads and the like may pass down the centre of the compression rods so that, for example, an electric bulb may be mounted on the adjustable arm.

Referring now to Fig. 4, a clamp 40 in accordance with the present invention attached to a bar 43 is illustrated securing thereto an elongated member, in this case a post 13, to which is attached another elongated member 41 by a conventional screw-type clamp 42. Nonetheless, an adjustable arm could be attached to the post 13 as shown in Fig. 1 or indeed any other suitable attachment could be connected thereto.

As best seen in Fig. 5, the clamp 40 has a projection 44 on the surface of frame 46 adjacent bar 43, the projection 44 resting on the top of the bar, and a rotatable member or

cam 45 which abuts the bottom of the bar which together hold the frame on the bar. The cam 45 is secured in either of holes 48 and 49 (depending on the spacing required between projection 44 and the cam which is of course dependent on the width of the bar) by screwing cam bolt 50 into the threaded bore 47 on the cam. A cam handle 52 and cam lock bolt spacer 51 are also provided. As the threaded bore 47 is not central, rotation of the cam 45 is eccentric and thus the distance between cam 45 and projection 44 varies depending on the degree of rotation on the cam. Bars of varying width may therefore be gripped by rotating cam 45 so that the appropriate gap is provided.

Typically, any bar from 25 mm x 5 mm to 50 mm x 12 mm may be fitted. Furthermore, this type of clamp may be fitted directly to a bar at the place desired whereas the prior art clamps have flanges which encircle the bar and are tightened with a screw clamp and thus must be slid along the bar to the appropriate position. This creates significant difficulty if a third clamp need by positioned between two clamps already in use since one of the two had to be temporarily removed.

The clamp 40 further comprises a spigot 53 extending through an opening 58 in the frame 46. The spigot 53 has a flange 57 that prevents it passing right through opening 58, and also has an opening 56 therein which accommodates post 13 and a threaded bore 59 which receives clamp 55. A collar 54 encircles spigot 53 and has a plurality of teeth which engage complementary teeth on frame 46 on one side and on the other side has a plurality of cut-out portions which lie over

opening 56 in the spigot. When collar 54 is slid along the spigot 53 away from the frame 46 it is released from engagement therewith and may rotate about the spigot. As the cut out portions, are of different shapes when a particular shape at top bottom is selected, a post of complementary configuration may be gripped with a better fit.

Figs. 6 and 7 illustrate a pivotable support 14 in accordance with the present invention. The support 14 includes a frame member 60 which partly encircles a ball 61 made of a resilient dielectric material such as plastic which is adapted to receive the implement to be supported. The ball 61 is pivotally supported in the frame 60 by cup member 62 which is simply held in bore 64 by virtue of a forced fit. Cup member 63 is secured to frame 60 by screw 65 which has a threaded portion engages the threaded bore 66 in the frame and an unthreaded portion or spigot which passes through the cup member and is swaged over the edge of the bore through the cup member which to hold it in place. Thus, turning screw 65 adjusts the position of the cup member 63 with respect to the frame and the other cup member 62 but cup member 63 is still freely rotatable on the screw 65. The ball 61 is thus firmly held between the two cup members but is nonetheless freely rotatable until screw 65 is turned further whereupon enough pressure is applied to clamp the ball 61 between the cup members and prevent it moving.

The ball 61 includes a bore 68 therethrough for receiving an implement. The bore 68 is in connection with a mouth 69 that is slightly narrower than the bore so that the

implement (or an appropriate shaped portion thereof) may be snapped in and out.

The frame 60 also includes a threaded bore 70 which engages the threaded portion 71 of a mounting arm, which may be an adjustable arm 11 as shown in Fig. 1, or a mounting member held in the arm. An unthreaded portion or spigot 72 engages a shallow depression 67 on the ball 61. This prevents excessive rotation of the ball 61 which may result in it falling out of frame 60 and also prevents the implement being held from touching the conductive frame.

Figs. 8 and 9 illustrate a sling 80 which is mounted on an adjustable arm 11. The sling 80 consists of a hollow tube

81 capped at the top 83 which has a loop 82 to which a surgical patient's arm is attached protruding from the bottom. A slide member 84 located in the tube 81 has a spring 85 disposed between it and the bottom flange 80 of the tube. When a patient's arm is attached to the loop 82, its weight tensions the cord 86 thereby compressing the spring

85. Since the arm is a deadweight, slight movements of the arm are resisted either by the spring or the weight of the arm. Nonetheless, if the patient goes into spasm the spring will compress further and can expand so that the patient's arm can move. This is important since a conventional fixed clamp does not allow any movement so the patient may be injured if the arm goes into spasm.

Fig. 10 shows a spacer member supporting an adjustable arm 11 on a pole 13. The purpose of the spacer member is to give a greater mobility to the arm 11 about a plane centred

on the post 13. A pair of parallel struts 91, 92 are fixed to the pole 13 by screw clamp 88 which is able to pivot in a plane around post 13 as it is located on a rotatable collar 87. Attachment member 90 is pivotally secured between struts 91, 92 by screw clamp 89. The adjustable arm 11 is secured to attachment member 90 by screw clamp 93.

Variations and modifications apparent to those skilled in the art may be made without departing from the broad scope an ambit of the invention as described above.