referring to fig1 the disclosed embodiment of the universal scissors joint apparatus includes a first clamping member referred to as a scissors clamp 10 , a second clamping member referred to as a circle clamp 20 , a cam locking mechanism 30 , and a rod 40 . the rod 40 associates the cam locking mechanism 30 , the circle clamp 20 , and the scissors clamp 10 . referring to fig1 , and 3 , the scissors clamp 10 includes two segments connected at a pivot 16 , similar to a scissors , so that the two segments cross each other at the pivot 16 . the first segment 12 includes an upper portion , referred to as an upper handle 12 a , of the scissors clamp 10 proximal of the pivot 16 and engaging the rod 40 ; the first segment 12 further includes two lower portions , referred to as lower grippers 12 b , of the scissors clamp 10 distal of the pivot 16 . the second segment 14 includes a lower portion , referred to as a lower handle 14 a , of the scissors clamp 10 proximal of the pivot 16 ; the second segment 14 further includes an upper portion , referred to as an upper gripper 14 b , of the scissors clamp 10 distal of the pivot 16 . the grippers 12 b , 14 b of the scissors clamp 10 are shaped so as to contour the surface of the object ( not shown ) to which the clamp is being attached . the inner surface of the upper gripper 14 b of the scissors clamp 10 may include indentations 14 c . these indentations 14 c may be located opposite the lower grippers 12 b . the handles 12 a , 14 a of the scissors clamp 10 are separated by a gap that allows the scissors clamp 10 to be squeezed , creating a tighter grip on the instrument being held by the grippers 12 b , 14 b of the clamp . the handles 12 a , 14 a of the scissors clamp 10 each have an opening that allows the rod 40 to pass through . a bushing 50 may be used . the bushing 50 may surround the rod 40 and fit into the opening in the upper handle 12 a . the circle clamp 20 includes an upper portion 22 and a lower portion 24 connected to form a single piece . the upper portion 22 and lower portion 24 are connected at a circular shaped fulcrum 26 . the fulcrum 26 has a circular hole 28 in it . the hole 28 allows for the insertion of a retractor , rail , or other object ( not shown ). except for the connection at the fulcrum 26 , a gap exists between the upper portion 22 and lower portion 24 of the circle clamp 20 . the gap allows the circle clamp 20 to be squeezed , tightening the grip on the object being held in the circle clamp 20 . a spacer 60 may lie within this gap . both the upper portion 22 and lower portion 24 of the circle clamp 20 have an opening through which the rod 40 may pass . the opening in the lower portion 24 may fit the same bushing 50 that engages the scissors clamp 10 . referring to fig1 , and 5 , the locking mechanism 30 includes a handle 32 connected to a cam 34 . the handle 32 consists of a first straight portion 32 a , an elbow 32 b , and a second straight portion 32 c . the first straight portion 32 a projects straight out from the cam 34 , then the elbow 32 b curves at an angle before the second straight portion 32 c projects straight out from the elbow 32 b . the second straight portion 32 c of the handle 32 includes a recessed area 36 . the cam 34 may be shaped asymmetrically with respect to the center axis 33 of the handle , so that the cam &# 39 ; s center axis 35 is not aligned with the handle &# 39 ; s center axis 33 . the cam 34 is positioned through an eyehole 42 in the rod 40 . alternatively , the cam &# 39 ; s center axis 35 may be aligned with the handle &# 39 ; s center axis 33 where the cam 34 is not circular but instead has different radial lengths along different points of its perimeter , as will be appreciated by those skilled in the art . referring to fig3 and 5 , the rod 40 associates the scissors clamp 10 , circle clamp 20 and the cam locking mechanism 30 . the rod 40 has an eyehole 42 at one end through which the cam 34 may be inserted . at the opposite end , the rod 40 may be connected to a nut 70 . a spring 80 surrounds the rod 40 between the nut 70 and the lower handle 14 a of the scissors clamp 10 . alternatively , the rod 40 may be directly attached to the lower handle 14 a of the scissors clamp 10 . referring to fig3 , and 6 , the universal scissors joint is engaged by rotating the cam handle 32 from an open position 38 to a locked position 39 . rotating the cam handle 32 rotates the cam 34 within the eyehole 42 . this pushes the rod 40 upward , which causes the nut 70 and spring 80 to press upward on the lower handle 14 a of the scissors clamp 10 . because the upper handle 12 a of the scissors clamp 10 is connected by the bushing 50 to the lower portion 24 of the circle clamp 20 , and the circle clamp 20 is a single piece , as the nut 70 and spring 80 move upward , both the scissors clamp 10 and the circle clamp 20 are squeezed , creating a tighter grip on the objects being held within the clamps . referring to fig1 , 5 , and 6 the scissors clamp 10 and the circle clamp 20 are able to rotate with respect to each other . this allows any attached rods or surgical devices to be positioned in any manner desired for surgery . the ability to rotate may be locked or unlocked by the locking mechanism 30 . when the cam handle 32 is in the open position 38 , the scissors clamp 10 and the circle clamp 20 are able to freely rotate with respect to each other . when the cam handle 32 is in the locked position 39 , the ability of the two clamps to rotate with respect to each other is made extremely difficult , with the result establishing a fixed position for the clamps with respect to each other so long as the cam handle 32 is in the locked position 39 . as the cam handle 32 is rotated into the locked position 39 , the upper handle 12 a of the scissors clamp 10 is pressed against the bushing 50 with greater force , and the lower portion 24 of the circle clamp 20 is also pressed against the bushing 50 with greater force . this greater force creates greater friction between the scissors clamp 10 and the bushing 50 and between the circle clamp 20 and the bushing 50 , greatly restricting the ability of the scissors clamp 10 and the circle clamp 20 to rotate with respect to each other . although the present invention has been described in considerable detail with reference to certain preferred versions thereof , other versions are possible . for example , types of clamps other than the circle clamp 20 may be used in conjunction with the scissors clamp 10 , and more than two clamps may be used in one device . it will be appreciated that different sizes and shapes of the clamps may be used without departing from the scope of the present invention . different types of cam locking mechanisms may be used , such as that revealed in u . s . pat . no . 5 , 888 , 197 . still other types of locking mechanisms may be employed , such as a threaded locking mechanism . it will be appreciated that the handle and the cam may assume different shapes without departing from the scope of the present invention . it will be appreciated that the positions that constitute the locked and unlocked position may be changed without departing from the scope of the present invention . the revealed embodiment is not able to be completely disassembled , so as to allow sterilization without disassembly , but other embodiments may be completely disassembled . therefore , the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein .
a universal joint apparatus comprises clamps , a locking mechanism , and a rod connecting the clamps and the locking mechanism . at least one clamp is a scissors clamp , i . e . a clamp comprising two segments fastened by a pivot . the scissors clamp generates extra compressive force on the object being held , providing a stable and rigid universal joint . clamps are able to rotate with respect to each other , allowing for greater flexibility in usage . the universal joint apparatus is capable of being added to a support frame between other components