U.S. patent application number 11/413607 was filed with the patent office on 2006-11-23 for surgical clamp.
This patent application is currently assigned to Minnesota Scientific, Inc.. Invention is credited to Christopher Lee Berg, Todd M. Bjork, Todd William Sharratt.
Application Number | 20060264711 11/413607 |
Document ID | / |
Family ID | 34422289 |
Filed Date | 2006-11-23 |
United States Patent
Application |
20060264711 |
Kind Code |
A1 |
Bjork; Todd M. ; et
al. |
November 23, 2006 |
Surgical clamp
Abstract
A surgical joint includes a first clamping member for engaging a
first support member and a second clamping member for engaging a
second support member. The first clamping member includes a
clamping bore wherein the first support member is positionable
within the clamping bore. The second clamping member includes a
socket wherein the second support member is positionable within the
socket. A shaft is disposed through the first clamping member and
is in communication with the second clamping member. An actuating
mechanism is coupled to the shaft wherein the actuating mechanism
is positionable to force the first clamping member frictionally
engages the first support member and the second clamping member
frictionally engages the second support member.
Inventors: |
Bjork; Todd M.; (River
Falls, WI) ; Sharratt; Todd William; (Birchwood,
MN) ; Berg; Christopher Lee; (Crystal, MN) |
Correspondence
Address: |
WESTMAN CHAMPLIN & KELLY, P.A.
SUITE 1400
900 SECOND AVENUE SOUTH
MINNEAPOLIS
MN
55402-3319
US
|
Assignee: |
Minnesota Scientific, Inc.
St. Paul
MN
55110
|
Family ID: |
34422289 |
Appl. No.: |
11/413607 |
Filed: |
April 28, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10681480 |
Oct 8, 2003 |
7097616 |
|
|
11413607 |
Apr 28, 2006 |
|
|
|
Current U.S.
Class: |
600/230 |
Current CPC
Class: |
A61B 90/57 20160201;
A61B 90/50 20160201; A61B 2090/571 20160201; A61B 17/02 20130101;
A61B 1/32 20130101 |
Class at
Publication: |
600/230 |
International
Class: |
A61B 1/32 20060101
A61B001/32 |
Claims
1-15. (canceled)
16. A clamp for accepting a substantially circular cross-sectional
rod comprising: a first clamping member comprising first and second
legs defining a clamping bore; and a plurality of raised portions
attached to the first clamping member and each of the raised
portions having arcuate surfaces extending into the clamping bore
wherein the arcuate surfaces engage are for engaging the
substantially circular cross-sectional rod.
17. The clamp of claim 16 and further comprising: a shaft
supporting the first and second legs; and an actuating mechanism
coupled to the shaft wherein the actuating mechanism is
positionable to force the first and second legs together thereby
creating a frictional engagement between the substantially circular
cross-sectional rod and the arcuate surfaces of the plurality of
raised portions.
18. The clamp of claim 17 wherein the actuating mechanism comprises
a camming member.
19. The clamp of claim 17 and further comprising a second clamping
member rotatably supported about the shaft and wherein the second
clamping member includes a socket for accepting a second support
member.
20. The clamp of claim 19 wherein the second clamping member
further comprises: a main body comprising the socket and a through
bore for receiving the shaft; and a clamping arm pivotally attached
to the main body wherein the clamping arm comprises a clamping
surface wherein the clamping arm is in communication with the shaft
such that when the actuating mechanism is positioned to
frictionally engage the first support member, the clamping arm
pivots such that second support member is frictionally engaged
between the clamping surface of the clamping arm and the surface
defining the clamping slot.
21. (canceled)
22. The clamp of claim 16 wherein the first clamping member further
comprises a pawl pivotally connected to the first clamping member
wherein an end of the pawl engages the first support member to
retain the first clamping member in a selected position on the
first support member when the first clamping member is not
frictionally engaging the first support member.
23. A clamp for accepting a substantially circular cross-sectional
rod comprising: a first clamping member comprising first and second
legs defining a clamping bore; and a plurality of raised portions
attached to the first clamping member and each of the rasied
portions having arcuate surfaces having radii that are less than
the radii of the clamping bore.
24. The clamp of claim 23 and further comprising: a shaft
supporting the first and second legs; and an actuating mechanism
coupled to the shaft wherein the actuating mechanism is
positionable to force the first and second legs together thereby
creating a frictional engagement between the substantially circular
cross-sectional rod and the arcuate surfaces of the plurality of
raised portions.
25. The clamp of claim 24 wherein the actuating mechanism comprises
a camming member.
26. The clamp of claim 24 and further comprising a second clamping
member rotatably supported about the shaft and wherein the second
clamping member includes a socket for accepting a second support
member.
27. A clamp for mounting on a support member comprising: a first
clamping member comprising first and second legs defining a
clamping bore; and a stop extending between the first and second
legs wherein the stop limits movement of the first and second legs
towards each other to prevent excessive clamping force from being
applied to the support member.
28. The clamp of claim 27 and further comprising a plurality of
raised portions attached to the first clamping member and having
arcuate surfaces having radii that are less than the radii of the
clamping bore.
29. The clamp of claim 27 and further comprising: a shaft
supporting the first and second legs; and an actuating mechanism
coupled to the shaft wherein the actuating mechanism is
positionable to force the first and second legs together wherein
the stop prevents further movement of the first and second legs
toward each other and wherein a surface defining the clamping bore
frictionally engages the support member.
30. The clamp of claim 29 wherein the actuating mechanism comprises
a camming member.
31. The clamp of claim 29 and further comprising a second clamping
member rotatably supported about the shaft and wherein the second
clamping member includes a socket for accepting a second support
member.
32. The clamp of claim 19 wherein the second clamping member
further comprises a flexible clamping member having wing portions
with clamping surfaces that define the socket and wherein as the
actuating mechanism forces the second clamping member to
frictionally engage the second support member, the wing portions
flex such that the clamping surface engage the second support
member.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to a surgical clamp
for use in mounting a retractor support apparatus with respect to
an operating table. More particularly, the present invention
relates to a clamp that can be positioned about the retractor
support apparatus in a selected position.
[0003] Prior to performing a surgical procedure requiring
retraction, a retractor support apparatus is typically constructed
about a surgical site. The retractor support apparatus is attached
to a field post that is attached to a surgical table with the field
post extending upwardly from the surgical table.
[0004] The retractor support apparatus extends over the surgical
table and can include as little as one support member or numerous
support members. Retractors and other surgical equipment are
positioned about the surgical site by being secured with a clamp
attached to the retractor support apparatus.
[0005] However, the retractor support apparatus can be burdensome
and difficult to position. Additionally, the clamp is typically
free to move along the length of the field post which creates
additional difficulty in securing the retractor support apparatus
with the clamp. Therefore, securing the retractor support apparatus
with a clamp and positioning the clamp in a selected position on
the field post can pose difficulties.
[0006] The design of the clamp can also add to the difficulty in
mounting the retractor support apparatus to the field post. The
retractor clamp typically includes first and second clamping
members that are generally in the shape of the letter "U". Clamping
members having U-shaped structures are disclosed in U.S. Pat. Nos.
4,718,151, 5,020,195, 5,242,240 and 5,7921,046, all of which are
assigned to the same assignee as the assignee of the present
application. The object to be clamped is placed in a clamping bore
defined by the legs of the U-shaped structure where movement of the
legs towards each other causes the object to be clamped within the
clamping bore.
[0007] However, the weight and configuration of the retractor
support apparatus may create potential difficulties in positioning
the end of the retractor support apparatus within the clamping
bore. Additionally, once the end of the retractor support apparatus
is positioned within the U-shaped structure, the retractor support
apparatus must be slid into a selected position prior to clamping
the retractor support apparatus in the selected position.
SUMMARY OF THE INVENTION
[0008] The present invention includes a surgical joint having a
first clamping member for engaging a first support member and a
second clamping member for engaging a second support member. The
first clamping member includes a clamping bore wherein the first
support member is positionable within the clamping bore. The second
clamping member includes a socket wherein the second support member
is positionable within the socket. A shaft is disposed through the
first clamping member and is in communication with the second
clamping member. An actuating mechanism is coupled to the shaft
such that the actuating mechanism is positionable to force the
first clamping member to frictionally engage the first support
member and the second clamping member to frictionally engage the
second support member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side view of the surgical clamp of the present
invention clamping a retractor support apparatus to a field post
clamped to a surgical table.
[0010] FIG. 2 is a perspective view of the surgical clamp of the
present invention.
[0011] FIG. 3 is an exploded view of the surgical clamp of the
present invention.
[0012] FIG. 4 is a sectional view of the surgical clamp of the
present invention in a clamping position along section line 4-4 in
FIG. 2.
[0013] FIG. 5 is a perspective view of an alternative embodiment of
the surgical clamp of the present invention.
[0014] FIG. 6 is an exploded view of the alternative embodiment of
the surgical clamp of the present invention.
[0015] FIG. 7 is a sectional view of the alternative embodiment of
the surgical clamp of the present invention in a clamping position
along section line 7-7 in FIG. 5.
[0016] FIG. 8 is a perspective view of another alternative
embodiment of the surgical clamp of the present invention.
[0017] FIG. 9 is an exploded view of the alternative embodiment of
the surgical clamp of the present invention.
[0018] FIG. 10 is a side view of the clamping bore of the first
clamping member of the present invention.
[0019] FIG. 11 is a side view of the pawl attached to the first
clamping member of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The present invention includes a surgical clamp illustrated
in FIG. 1 at 10. The surgical clamp 10 secures a retractor support
apparatus 18 to a field post 16 where the field post 16 is mounted
to a rail 14 of a surgical table 12.
[0021] Referring to FIG. 2, the surgical clamp 10 includes a first
clamping member 20 that engages the field post 16 and a second
clamping member 70 that engages the retractor support apparatus 18.
A shaft 90 is positioned through the first clamping member 20 and
engages the second clamping member 70. An actuating mechanism 100
is coupled to the shaft 90 where the actuating mechanism 100 is
positionable between a first position and a second position.
[0022] In the first position, the first and second clamping members
20, 70, respectively, are in a nonclamping position where the first
clamping member 20 is positionable on the field post 16. The
retractor support apparatus 18 is positionable within the second
clamping member 70 and the second clamping member 70 is rotatable
with respect to the first clamping member 20.
[0023] In the second position, the first and second clamping
members 20, 70, respectively, are positioned into clamping
positions. In the clamping position, the first clamping member 20
frictionally engages the field post 16, the second clamping member
70 frictionally engages the retractor support apparatus 18 and the
second clamping member 70 is rotatably fixed with respect to the
first clamping member 20.
[0024] The first clamping member 20 is of a unitary construction
having a first resilient leg 22 and a second resilient leg 24
defining a clamping bore 26. A clamping slot 28 separates the first
and second resilient legs 22, 24, respectively. The field post 16
is positioned within the clamping bore 26 where the first clamping
member 20 is positionable along a length of the field post 16.
Although the first clamping member 20 is described as having a
unitary construction, a non-unitary construction of the first
clamping member 20 is within the scope of the present
invention.
[0025] A pawl 32 is pivotally attached to a frame 30 extending from
the first clamping member 20. A gripping end 34 of the pawl 32
extends into the clamping bore 26 through a pawl passing slot 35
that intersects the clamping bore 26. The gripping end 34 engages
one of a plurality of annular grooves 15, preferably uniformly
spaced, along a length of the field post 16 to retain the first
clamping member 20 on the field post 16 when the clamp 10 is in the
non-clamping position. With the gripping end 34 positioned within
one of annular grooves 15, the first clamping member 20 is
rotatable about the field post 16.
[0026] A pivot pin 40 is positioned through through holes (33, not
shown) in sides of the pawl 32 and through holes (not shown) in
sidewalls of the frame 30 to pivotally attach the pawl 32 to the
first clamping member 20, as best illustrated in FIGS. 2, 3, and
11. Referring to FIG. 3, a compression spring 42 biases the
gripping end 34 of the pawl 32 within the clamping bore 26 and into
engagement with the plurality of annular grooves 15.
[0027] Referring to FIG. 11, the gripping end 34 of the pawl 32
includes a slanted surface 36 and a substantially right angled
surface 38. The slanted surface 36 slides over and does not engage
the plurality of annular grooves 15. The right angled surface 36
engages one of the plurality of the annular grooves 15 and retains
the first clamping member 20 on the field post 16 while the first
clamping member 20 is rotatable about the field post 16.
[0028] The design of the pawl 32 allows the first clamping member
20 to freely travel in the direction where the slanted surface
engages 36 the plurality of annular grooves 15 and prevents travel
in the opposite direction where the substantially right angled
surface 38 engages one of the plurality of the annular grooves 15.
To move the first clamping member 20 in the opposite direction of
the free travel, manual force is applied to the pawl 32 to overcome
the bias of the compression spring 42 which removes the gripping
end 34 from the clamping bore 26. With the gripping end 34 removed
from the clamping bore 26, the first clamping member 20 freely
travels along the field post 16 in either direction.
[0029] Referring to FIGS. 2, 3 and 10, the first clamping member 20
is secured onto the field post 16 by constricting the clamping bore
26 about the field post 16 by forcing the first and second
resilient legs 22, 24, respectively, together by positioning the
actuating mechanism 100 into the second clamping position.
Referring to FIG. 10, the clamping bore 26 is defined by raised
arcuate clamping surfaces 50, 52 and 54 which are separated by
recessed arcuate surfaces 44, 46 and 48. The recessed arcuate
surfaces 44, 46 and 48 are grooves within the clamping bore 26
which make the clamping surfaces 50, 52 and 54, the surfaces that
engage the field post 16.
[0030] In an exemplary configuration, the raised surface 50 is
located opposite the clamping slot 28 and the raised surfaces 52,
54 are located proximate to and separated by the clamping slot 28.
A clamping bore having two or more raised surfaces is within the
scope of the invention.
[0031] As the clamping bore 26 is constricted by a force applied to
the shaft 90 by the actuating mechanism 100, the raised surfaces
52, 54, respectively, contact the field post 16 and urge the field
post 16 into the raised surface 50. When the first clamping member
20 is in the clamping position, the field post 16 is frictionally
engaged along lengths of the raised surfaces 50, 52 and 54.
[0032] The clamping strength of the first clamping member 20 having
a grooved clamping bore 26 with the raised surfaces 50, 52 and 54
separated by the recessed surfaces or grooves 44, 46 and 48 is
significantly greater than that of a smooth surfaced clamping bore.
A significant amount of the clamping strength of a smooth bore
occurs at two points on a plane having a substantially orthogonal
relationship to the clamping slot 28 separating the first and
second resilient legs 22, 24, respectively. In comparision to
clamping substantially at two points, the first clamping member 20,
having the grooved clamping bore 26, engages the field post 16
along the lengths of the raised arcuate surfaces 50, 52, 54 which
significantly increases the clamping surface that frictionally
engages the field post 16 and thereby increases the clamping
strength of the first clamping member 20.
[0033] Referring to FIG. 3, a stop 56 is positioned into the
clamping slot 28 to prevent an excessive clamping force from being
applied to the field post 16 by the first clamping member 20.
Excessive clamping force can cause the metal from the field post 16
and/or the first clamping member 20 to wear. The stop 56 is
preferably a threaded bolt 58 that threadably engages a threaded
bore 60 in the first resilient leg 22 where an end 57 of the bolt
58 is positioned within the clamping slot 28. The bolt 58 is
secured into the selected position by deforming the threads through
a bore 59 intersecting the threaded bore 60.
[0034] Referring to FIG. 3 and 4, the actuating mechanism 100 is
preferably a camming pin 102 that is positioned within through
bores 64, 66 of a collar 62 such that a camming surface 110 is
positioned within a through bore 94 of a head 92 of the shaft 90.
The collar 62 is preferably an integral portion of the first
resilient leg 22 and includes a shaft head accepting bore 68 that
intersects the through bores 64, 66. However, the collar 62 may be
a separate component from the first clamping member 20 while being
within the scope of the present invention.
[0035] The camming pin 102 includes end portions 104, 106 and an
intermediate portion 108 having the camming surface 110. The end
portions 104, 106 and the intermediate portion 108 are generally
cylindrical in shape and are located adjacent one to another. The
end portions 104, 106 are centered about a rotational axis 112 and
are captivated within the through bores 64, 66, respectively. The
captivated end portions 104, 106 rotatably support the intermediate
portion 108 within the through bore 94 in the head 92 of the shaft
90.
[0036] The shaft 90 is positioned through the shaft head accepting
bore 68 which is aligned with first and second shaft passing bores
23, 25 within the first and second resilient legs 22, 24,
respectively, until the head 92 is positioned within the shaft head
accepting bore 68. The shaft head accepting bore 68 is elongated to
allow the required movement of a head 92 of the shaft 90 when the
clamp 10 is positioned from the first nonclamping position to the
second clamping position and also in the reverse direction as best
illustrated in FIG. 2.
[0037] Referring to FIGS. 3, and 4, the intermediate portion 108 is
eccentrically coupled between the end portions 104, 106. The
intermediate portion 108 has an axis 114 that is spaced from the
rotational axis 112 of the camming pin 102 by a selected distance.
The distance separating the axis 112 of the camming pin 102 and the
axis 114 of the intermediate portion 108 generally determines the
maximum distance that the camming pin 102 moves the shaft 90
relative to the first and second clamping members 20, 70,
respectively. Preferably, the distance separating the axis 112 of
the camming pin 102 and the axis 114 of the intermediate portion
108 is sufficient to frictionally secure the field post 16 and the
retractor support apparatus 18 within the first and second clamping
members 20, 70, respectively.
[0038] Other camming mechanisms besides the camming pin 102
described are within the scope of the invention, including, but not
limited to, an irregular shaped lobe, a head having increasing
radii to an external surface from a pivot point and an eccentric.
Other actuating mechanisms 100 besides a camming mechanism are also
within the scope of the invention including but not limited to a
moving wedge or a threaded rod as described in U.S. Pat. Nos.
4,718,151, 5,020,195 or 5,242,240 herein incorporated by
reference.
[0039] Referring to FIGS. 2-4, the second clamping member 70 is
positioned proximate the second resilient leg 24. The second
clamping member 72 includes a main body 72 having a socket 74 that
accepts the retractor support apparatus 18. A clamping lever 80
pivotally attached to the main body 72 by a pivot pin 81 includes
an arcuate surface 82 on a first leg 84 that constricts an entrance
73 to the socket 74. By socket is meant an opening or a cavity into
which an inserted part, such as a retractor support apparatus, is
designed to fit and wherein the retractor support apparatus can be
inserted into the socket from an infinite number of directions in a
180.degree. range starting from a substantially parallel position
to a back surface of the socket to a position substantially
perpendicular to the back surface and continuing to position again
substantially parallel to the back surface of the socket.
[0040] To position the retractor support apparatus 18 within the
socket 74, the retractor support apparatus 18 is positioned
proximate the entrance 73 to the socket 74 defined by surfaces 75
of first and second walls 76, 78 separated by a back surface 77.
Manual force is applied to the retractor support apparatus 18
substantially perpendicularly to an axis 17 to position the
retractor support apparatus 18 within the socket 74. However, the
retractor support apparatus 18 can be inserted from any position
within a substantially 180.degree. range as discussed
previously.
[0041] The retractor support apparatus 18 is retained within the
second clamping member 70 by the arcuate surface 82 of the clamping
lever 80 and the surfaces 75 of the first and second walls 76, 78.
A compression spring 93 is positioned about the shaft 90 and biases
the clamping lever 80 toward a clamping position which retains the
retractor support apparatus 18 within the socket 74 as best
illustrated in FIGS. 3 and 4. With the retractor support apparatus
18 retained within the socket 74, the retractor apparatus 18 is
slidably positionable parallel to the axis 17 within the second
clamping member 70.
[0042] The clamping lever 80 is positioned within a channel 79 in
the first wall 76 and is pivotally attached to the first wall 76 by
the pivot pin 81. The pivot pin 81 is positioned through aligned
bores 120, 122 intersecting the channel 79 and through bore 83 in
the clamping lever 80.
[0043] The retractor support apparatus 18 is fixedly retained in a
select position by positioning the actuating mechanism 100 into the
second clamping position by applying a force to the clamping lever
with a bolt 130 disposed through an elongated through bore 85
within a second leg 86 of the clamping lever 80. The bolt 130
includes a threaded end portion 132 that threadably engages an
internal threaded bore 96 within the shaft 90.
[0044] A head 134 of the bolt 130 is positioned within a
counter-sunk recess 87 about the through bore 85 such that the head
134 of the bolt 130 does not extend into the socket 74. The first
and second legs 84, 86 respectively of the clamping lever 80 are
generally configured in the shape of the letter "L". When the force
is applied to the second leg 96 by the bolt 130, the clamping lever
80 pivots about the pivot pin 81 such that the arcuate surface 82
of the first leg 84 engages the retractor support apparatus 18 as
illustrated with dotted lines in FIG. 2.
[0045] With the head 134 of the bolt 130 a selected distance from
the head 92 of the shaft 90, the first and second clamping members
20, 70, respectively, are positionable between the clamping and
non-clamping positions when the actuating mechanism 100 is in the
first non-clamping and second clamping positions, respectively. The
selected distance between the head 92 of the shaft 90 and the head
134 of the bolt 130 is fixed by inserting a punch into an opening
98 in the shaft 90 and deforming the threads to prevent the bolt
130 from threadably moving out of the threaded bore 96.
[0046] The second clamping member 70 is rotatably captivated with
respect to the first clamping member 20 by positioning a generally
cylindrical end portion 124 within the second shaft passing bore 25
of the second resilient leg 24. An annular groove 126 on the
generally cylindrical end portion 134 is positioned within the
clamping slot 28 and a snap ring 128 is positioned within the
annular groove 126 to captivate the second clamping member 70 with
respect to the first clamping member 20.
[0047] The second clamping member 70 is rotatably fixed with
respect to the first clamping member 20 when the camming pin 102 is
positioned into the second clamping position. The head 134 of the
bolt 130 forces the second clamping member 70 towards the first
clamping member 20 wherein a first frusto-conical surface 131 of
the second clamping member 70 frictionally engages a second
frusto-conical surface 31 of the second shaft passing bore 25.
[0048] In operation, the clamp 10 is typically used to clamp the
retractor support apparatus 18 to the field post 16, although the
clamp 10 can also be used to clamp a first rod to a second rod.
Preferably, the field post 16 includes the plurality of annular
grooves 15 uniformly spaced apart.
[0049] With the clamp 10 in the first non-clamping position, the
first clamping member 20 is slid over the field post 16 in a first
direction where the slanted surface 36 of the gripping end 34 of
the pawl 32 slides over the plurality of annular grooves 15 thereby
allowing the first clamping member 20 to freely move in the first
direction. Alternatively, the first clamping member 20 can be moved
in an opposite direction by displacing the gripping end 34 from the
clamping bore 27 by overcoming the bias of the compression spring
42. When the first clamping member 20 is in a selected position on
the field post 16 the substantially right angled surface 38 of the
gripping end 34 engages one of the annular grooves 15 such that the
first clamping member 20 is rotatably secured in the selected
position about the field post 16.
[0050] With the first clamping member 20 rotatably secured to the
field post 16 by the pawl 32, the retractor support apparatus 18 is
positioned proximate the constricted entrance 73 to the socket 74
of the second clamping member 70. Manual force is exerted upon the
retractor support apparatus 18 preferably substantially
perpendicular to the back surface 77 of the socket 74 (or within a
substantially 180.degree. range from the back surface 77) to
overcome the bias of the compression spring 93 on the clamping
lever 80 to position the retractor support apparatus 18 within the
socket 74. The retractor support apparatus 18 is retained within
the socket 74 by the arcuate surface 82 of the clamping lever 80
constricting the entrance 73 where the retractor support apparatus
18 is slidably positionable within the socket 74. The second
clamping member 70 is rotatably positioned into a selected position
with respect to the first clamping member 20.
[0051] With the first clamping member 20 in the selected position
on the field post 16 and the retractor support apparatus 18 in a
selected position with respect to both the field post 16 and the
second clamping member 20, the clamp 10 is positioned into the
second clamping position by manipulating a handle 101 attached to
the camming pin 102. As the handle 101 is moved, the camming pin
102 is rotated from the first non-clamping position to the second
clamping position, and the camming surface 110 of the intermediate
portion 108 contacts the through bore 94 within the head 92 of the
shaft 90 and generates a force upon the first and second clamping
members 20, 70, respectively.
[0052] The force applied to the first clamping member 20 causes the
first and second resilient legs 22, 24, respectively, to be forced
toward each other. As the first and second resilient legs 22, 24
are forced toward each other, the raised arcuate surfaces 50, 52
and 54 of the grooved clamping bore 26 frictionally engage the
field post 16.
[0053] The force also causes the head 134 of the bolt 130 to be
drawn into the counter-sunk recess 87 within the second leg 86 of
the clamping lever 80. As the head 134 of the bolt 130 is drawn
into the second leg 86, the clamping lever 80 pivots about the
pivot pin 81 and causes a frictional engagement between the arcuate
surface 82 of the clamping lever 80, the retractor support
apparatus 18 and the clamping surface 75 of the second clamping
member 70.
[0054] The force generated by the camming pin 102 rotatably fixes
the second clamping member 70 with respect to the first clamping
member 20. The second clamping member 70 is retained in a selected
position by the frictional engagement of the frusto-conical
surfaces 131, 31 of the second clamping member 70 and the second
resilient leg 24, respectively.
[0055] To relocate or readjust the retractor support apparatus 18
with respect to the field post 16, the camming pin 102 is
positioned from the second clamping position to the first
non-clamping position such that the retractor support apparatus 18
is slidably retained within the second clamping member 70. With the
camming pin 102 in the first non-clamping position, the second
clamping member 70 is rotatable with respect to the first clamping
member 20.
[0056] The retractor support apparatus 18 is removable from the
second clamping member 70 by applying a force preferably
substantially perpendicular to the back surface 77 of the socket 74
(or within the substantially 180.degree. range from the back
surface 77) in an opposite direction of the force used to position
the retractor support apparatus 18 within the socket 74. The force
causes the arcuate surface 82 of the clamping lever 80 to pivot
away from the entrance 73 to the clamping slot 94 by overcoming the
bias of the spring compression 93 such that the entrance 73 is not
constricted. With a non-constricted entrance 73, the retractor
support apparatus 18 is removable from the second clamping member
70.
[0057] Additionally, the location of the first clamp 20 can be
adjusted on the field post 16 by either moving the first clamping
member 20 in the direction of free travel where the slanted surface
36 of the gripping end 34 of the pawl 32 slides over the annular
grooves 15 of the field post 16. Alternatively, to move the first
clamping member 20 in the opposite direction, manual force is
applied to the pawl 32 to overcome the bias of the compression
spring 42 such that the gripping end 34 is positioned away from the
clamping bore 26. With the gripping end 34 positioned away from the
clamping bore 26, the first clamping member 20 can be positioned
along the field post 16 in either direction.
[0058] An alternative embodiment of the clamp of the present
invention is generally illustrated at 210 in FIG. 5. The embodiment
210 includes a similar first clamping member 20 and a different
second clamping member 270 from the first embodiment 10. In
describing the embodiment 210, like reference characters will be
used to describe like elements throughout the drawings.
[0059] Referring to FIGS. 5-7, the second clamping member 270
includes a flexing member 290 that slidably cooperates with a
spacer 272. The spacer 272 includes a substantially cylindrical end
portion 274 that is disposed within the second shaft passing bore
25 of the second resilient leg 24. An annular groove 276 on the
cylindrical end portion 274 is positioned within the clamping slot
28 and a snap ring 128 is positioned within the annular groove 276
to rotatably captivate the spacer 272 to the second resilient leg
24.
[0060] A retractor support apparatus 18 is positioned at a
constricted entrance 293 to a socket 294 defined by a clamping
surface 292 of the flexing member 290. The clamping surface 292 of
the flexing member 290 is generally aligned with cut out areas 279,
280 of the spacer 270 that allows the retractor support apparatus
18 to be positioned within the socket 294 without interference from
the spacer 270. Manual force is applied to the retractor support
apparatus 18 preferably substantially perpendicularly to a bottom
surface 289 (or within the substantially 180.degree. range from the
back surface 289) of the socket 294 to position the retractor
support apparatus 18 within the socket 294.
[0061] The constricted entrance 293 slidably retains the retractor
support apparatus 18 within the socket 294 where the retractor
support apparatus 18 is movable along the axis 17. The force
exerted by the compression spring 93 upon a bolt 130 disposed
through bores in the flexing member 290 and the spacer 270 and
threadably engaging the shaft 90 biases the flexing member 290 to
make the constricted entrance 293.
[0062] The bolt 130 is connected to the shaft 90 by a threadable
engagement of a threaded end 132 with the threaded bore 96 within
the shaft 90. The bolt 130 is manipulated until a distance from the
head 92 of the shaft 90 to the head 134 of the bolt 130 is a
selected distance where the first and second clamping members 20,
270, respectively, are positionable between non-clamping and
clamping positions when the camming pin 102 is positioned from the
first non-clamping position to the second clamping position,
respectively. With the bolt 136 in the selected position, the
threads of the threaded end 132 are deformed by positioning a punch
in the opening 93 in the shaft 90 to fixedly retain the bolt 130
within the shaft 90.
[0063] Referring to FIGS. 6 and 7, the second clamping member 270
is positioned into the clamping position when the camming pin 102
is positioned into the second clamping position. The camming pin
102 urges the head 134 of the bolt 130 toward the first clamping
member 20 and exerts a force on the flexing member 290 and the
spacer 272. The force applied to the spacer 272 creates a
frictional engagement between a frusto-conical surface 278 of the
spacer 272 with the frusto-conical surface 31 of the second
resilient leg 24. The frictional engagement between the
frusto-conical surfaces 278, 31 prevents the spacer 272 from
rotating with respect to the second resilient leg 24,
respectively.
[0064] The retractor support apparatus 18 is frictionally engaged
by the clamping surface 292 defining the socket 294. The clamping
surface 292 is defined by inner surfaces of first and second wings
300, 302, respectively, separated by the arcuate bottom surface
289. As the flexing member 290 is drawn into the spacer 270,
arcuate tapered outer surfaces 304, 306 of the first and second
wings 300, 302, respectively, slidably engage arcuate tapered inner
surfaces 282, 284 of first and second sidewalls 286, 288 of the
spacer 270. As the arcuate outer tapered surfaces 304, 306 of the
first and second wings 300, 302, respectively, slidably engage the
inner arcuate tapered surfaces 282, 284 of the first and seconds
sidewalls 286, 288, respectively, first and second cut outs 308,
310 located between the first and second wings 300, 302,
respectively, and an end portion 312 flex.
[0065] The first and second cut outs 308, 310 flex to conform the
arcuate tapered outer surfaces 304, 306 of the first and second
wings 300, 302 with an angle of pitch of the arcuate tapered inner
surfaces 282, 284 of the first and second sidewalls 286, 288, all
respectively. As the arcuate tapered outer surfaces 304, 306 of the
first and second wings 300, 302 conform to the arcuate tapered
inner surfaces 282, 284 of the first and second sidewalls 286, 288,
the socket 294 is constricted. The constricted socket 294 creates
the frictional engagement between the clamping surface 292 and the
retractor support apparatus 18.
[0066] In the non-clamping position an angle of pitch of the
arcuate tapered outer surfaces 304, 306 of the first and second
wings 300, 302 is shallower than an angle of pitch of the arcuate
tapered inner surfaces 282, 284 of first and second sidewalls 286,
288 such that the arcuate tapered outer surfaces 304, 306 do not
completely engage the arcuate tapered inner surfaces 282, 284. In
the non-clamping position, the retractor support apparatus 18 is
slidably positionable within the socket 294.
[0067] An end portion 312 of the flexing member 290 is rotatably
fixed and slidable within a counter-bored recess 283 positioned
about the through bore in the spacer 270. The end portion 312
includes a generally square cross-section that is positioned within
the counter-bored recess 283 which also has a generally square
cross-section. Flat surfaces of the end portion 312 engage flat
surfaces of the counter-bored recess 283 to prevent the flexing
member 290 from rotating within the spacer 270.
[0068] In operation, the camming pin 102 is positioned into the
first non-clamping position where the first clamping member 20 is
positionable on the field post 16. The first clamping member 20 is
retained in a selected position on the field post 16 by the
substantially right angled surface 38 of the pawl 32 engaging one
of the annular grooves 15 of the field post 16.
[0069] The retractor support apparatus 18 is positioned proximate
the constricted entrance 293 to the socket 294 of the second
clamping member 270. Manual force is applied substantially
perpendicularly to the axis 17 of the retractor support apparatus
18 and preferably substantially perpendicularly to the back surface
289 (or within the substantially 180.degree. range from the back
surface 289) of the socket 294 to overcome the constricted entrance
293 created by the bias of the compression spring 93 to position
the retractor support apparatus 18 within the socket 294. With the
retractor support apparatus 18 positioned within the socket 294,
the retractor support apparatus 18 is slidably positioned into a
selected position within the socket 294 and rotated into a selected
orientation with respect to the field post 16.
[0070] With the retractor support apparatus 18 in the selected
position, the handle 101 which is fixedly attached to the camming
pin 102 is moved to rotate the camming pin 102 from the first
non-clamping position to the second clamping position. With the
camming pin 102 in the second clamping position, the first clamp 20
frictionally engages the field post 16 as previously described.
[0071] As the camming pin 102 is rotated into the second position,
the head 134 of the bolt 130 is raised with respect to the second
clamping member 270 and pulls the flexing member 290 into the
spacer 270. As the flexing member 290 is pulled into the spacer
270, the first and second cut outs 308, 310 flex such that the
arcuate tapered outer surfaces 304, 306 of the first and second
wings 300, 302 conform to the arcuate tapered inner surfaces 282,
284 of the first and second sidewalls 286, 288, all respectively.
As the first and second wings 300, 302 conform to the pitch of the
arcuate tapered inner surfaces 282, 284 of the first and second
sidewalls 286, 288, the socket 294 constricts and creates a
frictional engagement between the clamping surface 292 and the
retractor support apparatus 18.
[0072] The spacer 270 is forced into the second resilient leg 24 of
the first clamping member 20 such that the frusto-conical surface
278 of the spacer 270 frictionally engages the frusto-conical
surface 31 of the second resilient leg 24. The frictional
engagement of the frusto-conical surfaces 278, 31 prevents the
spacer 270 from rotating with respect to the first clamping member
20.
[0073] To relocate or readjust the retractor support apparatus 18
with respect to the field post 16, the camming pin 102 is
positioned from the second clamping position to the first
non-clamping position such that the retractor support apparatus 18
is slidably retained along the axis 17 within the second clamping
member 270. With the camming pin 102 in the first non-clamping
position, the flexing member 290, having spring characteristics,
returns to a non-flexed state and the retractor support apparatus
18 is removable from the second clamping member 270 by applying a
force substantially perpendicular to the bottom surface 289 (or
within the substantially 180.degree. range from the back surface
289) of the socket 294 and away from the second clamping member
270.
[0074] Another embodiment of the clamp of the present invention is
generally illustrated at 410 in FIG. 8. The embodiment 410 includes
a substantially similar first clamping member 20 and a different
second clamping member 470 from the first embodiment 10 and the
first alternative embodiment 210. Like reference characters will be
used to describe like elements throughout the drawings.
[0075] Referring to FIGS. 8 and 9, the second clamping member 470
comprises a unitary structure having a socket 472 defined by a
surface 474 including a back surface 475 for engaging and retaining
a retractor support apparatus 18. The retractor support apparatus
18 is positioned proximate a constricted entrance 476 to the socket
472. Manual force is exerted upon the retractor support apparatus
18 substantially perpendicularly to the back surface 475 (or within
the substantially 180.degree. range from the back surface 475) of
the socket 294. The retractor support apparatus 18 is forced into
the socket 472 and retained within the socket 472 by the
constricted entrance 476.
[0076] The second clamping member 470 is rotatably attached to the
first clamping 20 member with a bolt 130 positioned through a
through bore 478 within the second clamping member 470 where the
bolt 130 threadably engages the threaded internal bore 96 within
the shaft 90. With a head 134 of the bolt 130 a selected distance
from the head 92 of the shaft 90, a portion of the threads 132 are
deformed to retain the bolt 130 within the shaft 90. The head 134
of the bolt 130 is positioned within a counter-bored recess 480
about the through bore 478 such that the head 134 does not
interfere with the retractor support apparatus 18 being positioned
within the socket 472.
[0077] The clamp 410 is positioned into a clamping position where a
substantially flat surface 482 of the second clamping member 470
frictionally engages a substantially flat surface 484 of a
cylindrical extension 486 extending from the second resilient leg
24. The frictional engagement of the substantially flat surfaces
482, 484 rotatably fixes the position of the second clamping member
470 with respect to the first clamping member 20.
[0078] To position the first and second clamping members 20, 470,
respectively into the clamping position, the handle 101 which is
attached to the camming pin 102 is moved such that the camming pin
102 is rotated from the first non-clamping position to the second
clamping position. With the camming pin 102 in the second clamping
position, the first clamping member 20 frictionally engages the
field post 16 as previously described.
[0079] The second clamping 470 is secured in a selected position by
forcing the head 134 of the bolt 130 into the second clamping
member 470. The force created by the head 134 of the bolt 130 on
the second clamping member 470 causes a frictional engagement
between the substantially flat surface 482 of the second clamping
member 470 and the substantially flat surface 484 of the generally
cylindrical extension 486, thereby retaining the second clamping
member 470 in the selected position.
[0080] To reposition the first clamping member 20 on the field post
16, the camming pin 102 is positioned into the first non-clamping
position. Additionally, with the camming pin 102 in the first
position, the second clamping member 470 is rotatable with respect
to the first clamping member 20.
[0081] To remove the retractor support apparatus 18 from the socket
472, manual force is applied to the retractor support apparatus 18
substantially perpendicularly to the back surface 475 (or within
the substantially 180.degree. range from the back surface 475) of
the socket 472. Manual force overcomes the constricted opening 476
such that the retractor support apparatus 18 is removed from the
socket 472.
[0082] Although the present invention has been described with
reference to preferred embodiments, workers skilled in the art will
recognize that changes may be made in form and detail without
departing from the spirit and scope of the invention.
* * * * *