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Claims  |
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I claim:
1. A surgical retractor adapted to be adjustably mounted on a supported
holder, said retractor comprising an elongated stem having a cylindrical
cross-section, having an exterior, and having blade means for contacting
tissue adjacent an incision attached to one end of said stem; the exterior
of said stem being provided with a plurality of axially spaced
circumferential detent means adapted to be selectively engaged by a
pivotal protuberance carried on the holder and being normally biased
toward engagement with said detent means, thereby restraining longitudinal
movement of the elongated stem in one direction.
2. The retractor of claim wherein the stem includes an inner section having
an end thereof attached to said blade means, and an outer section hingedly
connected to an opposite end of said inner section; said outer section,
when in one position of hinged adjustment, providing a handle for exerting
a manual pulling and rotational forces on said stem inner section and the
blade means attached thereto.
3. A surgical retractor, a supported holder thereof, and a frame support
having an exterior on which said holder is mounted in a selected position;
said frame support having at least a portion thereof of a substantially
cylindrical cross-sectional configuration with at least one longitudinally
extending indentation formed in the exterior thereof, said frame support
portion being substantially surrounded by a section of said holder, said
holder section being provided with protruding means engaging the
indentation of said frame support portion whereby the latter and the
holder assume a non-rotating relation.
4. A surgical retractor, a supported holder therefor, and a frame support
on which said holder is mounted in a selected position, said frame support
having an exterior; said retractor having an elongated stem of a
substantially cylindrical cross-sectional configuration and provided with
a plurality of external longitudinally spaced circumferential detent
means; said holder having a passage formed therein for slidably
accommodating said retractor stem, and a pivotal protuberance mounted on
said holder adjacent one end of said passage, said pivotal protuberance
being adapted to automatically engage said detent means permitting
relative sliding movement of said retractor stem in only one direction.
5. The surgical retractor, holder and frame support of claim 4, said
pivotal protuberance being provided with manually engagable means for
adjusting said pivotal protuberance to a release position whereby relative
movement of said stem within said holder passage is unrestrained.
6. The surgical retractor, holder and frame support of claim 5 wherein the
retractor stem includes hingedly connected inner and outer sections, at
least said inner section being provided with said external circumferential
grooves; the outer section being adapted to assume a handle-forming
predetermined position of hinged adjustment relative to said inner section
to facilitate manual pulling of said retractor in one direction and manual
rotation of the retractor about the stem inner section as an axis.
7. The surgical retractor, holder and frame support of claim 6, wherein the
retractor is adapted to be manually rotated about the stem inner section
as an axis, when said latch is in engagement with a circumferential detent
of said stem inner section.
8. The surgical retractor, holder and frame support of claim 4 wherein the
holder includes a first member adjustably mounted on the frame support,
and a second member removably connected to said first member, said second
member having a portion thereof for slidably accommodating a retractor
stem and means adjustably mounted on said portion and engaging said
retractor stem for retaining same in a selected position of adjustment
with respect thereto.
9. The surgical retractor, holder and frame support of claim 8 wherein the
holder first member is provided with a bifurcated portion to which said
second member is removably connected; said retractor stem and said frame
support portion when connected to said holder being in angularly disposed
relation.
10. A surgical retractor, a supported holder therefor, and a frame support
on which said holder is mounted in a selected position, said frame support
having an exterior; said frame support having at least a portion thereof
of a substantially cylindrical cross-sectional configuration with at least
one longitudinally extending indentation formed in the exterior thereof;
said holder having a clip segment comprising a channel portion adapted to
accommodate a portion of said frame support and spring means overlying
said channel portion adapted for frictionally locking said holder at a
selected position on said frame support, a portion of said clip segment
engaging said frame support being provided with protruding means engaging
the indentation of said frame support portion and coacting therewith
whereby the latter and said holder assume a non-rotating relation.
11. A surgical retractor, a supported holder therefor, and a frame support
on which said holder is mounted in a selected position, said frame support
having an exterior; said retractor having an elongated stem of a
substantially cylindrical cross-section configuration and provided with a
plurality of external longitudinally spaced circumferential first means;
said holder having a passage formed therein for slidably accommodating
said retractor stem, and an adjustable complemental second means mounted
on said holder adjacent one end of said passage, said second means being
adapted to automatically engage said first means permitting relative
sliding movement of said retractor stem in only one direction; and, said
frame support has at least a portion thereof of tubular construction with
the exterior thereof provided with at least one longitudinally extending
indentation, and the holder is provided with a segment for substantially
embracing the frame support portion, said holder segment being provided
with protruding means for slidably engaging the indentation of said frame
support portion. |
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Claims  |
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Description  |
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BACKGROUND OF THE INVENTION
A. Field Of The Invention
This invention relates to surgical implements, and, in particular, to
devices known as retractors.
B. Brief Description Of The Prior Art
Retractors are devices used by the surgeon to hold open a large incision
while a major operation is performed. They are supported above the site of
the incision by a retractor frame which is secured to the operating table,
usually in a horizontal position. Such frames are available in a variety
of sizes and configurations in order to suit the particular surgical
procedure to be performed. For example, such frames may be linear,
circular or U-shaped, and they may be constructed of flat steel strips or
of tubular steel.
Retractors are mounted upon the retractor frame by holders which both
secure the retractor to the frame and provide a means by which the degree
of retraction may be adjusted. Typically, the retractor itself is made of
surgical stainless steel and comprises a smooth blade which engages the
incision, a stem by which the retractor is supported, and a handle by
which the surgeon pulls the retractor to the desired position. A fastener
on the holder grasps the stem of the retractor and maintains it in the
desired position.
As can be clearly seen in FIG. 1 of the drawings, in any given surgical
procedure, a variety of retractors may be utilized. One problem which has
arisen under such circumstances is that the handle, or proximal, ends of
conventional solid-stemmed retractors extend out from the operating field
and may become obstacles to the surgeon's freedom of movement. Thus, the
surgeon's attention must not only be directed to the procedure at hand,
but must also be directed to avoiding contact with the ends of the various
retractors which may be in use.
Another attribute of conventional retractors is that their stems are
generally flat in cross-section, and no adjustment of the planar
orientation of the blade is therefore possible. This can be a significant
drawback to obtaining an optimal exposure of the operative site.
Conventional retractors are, as shown by FIG. 1, secured to their holders
by a variety of fasteners. Such fasteners permit the position of the
retractor to be changed by first loosening a wing nut or other screw type
member, adjusting the retractor to the desired position, and then
retightening the nut or screw to lock the retractor into its new position.
This procedure is somewhat time consuming, and it not only lengthens the
time required to first open the incision to the desired degree, but, more
importantly, makes adjustment during the operation considerably more
cumbersome than necessary at a time when speed is most desirable.
As with conventional retractors, certain inconveniences are associated with
the use of conventional retractor holders.
Where a retractor frame of circular cross section is employed, the holder
typically is a solid block of metal having a narrow cut extending from one
edge into a central cylindrical passage through which the retractor frame
may be inserted, and having a fastener which, when tightened, compresses
the block, clamp-like, onto the frame. Such holders must be attached to
the frame by sliding each one, in its proper sequence, onto the end of the
frame. If one type of holder is put onto the frame out of proper sequence,
or if the sequence of holders is later desired to be changed, all holders
between the one desired to be moved and the nearest frame end must be
removed and then replaced. In such circumstances, the frame supports
themselves must be released and then resecured in order to accomplish the
desired change.
A further drawback inhering in the conventional holder designed for use on
a cylindrical cross-section frame is that rotation of the holder about the
frame may occur. While generally sufficient clamping action is obtained
when the conventional aluminum holder is clamped to a conventional tubular
stainless steel frame, the union of these two smooth surfaces--the
interior surface of the holder and the exterior surface of the
frame--nonetheless can permit some rotation if, for example, the stem of
the retractor carried by the holder is accidentally struck from above.
A further drawback of conventional holders lies in their solid
construction, particularly the cylindrical passage through which the
retractor frame is passed. The difficulty with this construction lies in
the fact that such a holder cannot slide around any curved portions of a
frame, such as a U-shaped frame, thus limiting the range of positions into
which the holder can be placed.
SUMMARY OF THE INVENTION
Thus, it is an object of the present invention to overcome the
inconvenience and disadvantages of the conventional retractor components
in a number of respects.
In particular, it is one object of the invention to provide a retractor
having stem which does not present a physical obstacle to the surgeon's
movements during the operation.
A second object of the present invention is to provide a retractor which is
angularly adjustable so as to maximize the range of blade positions
available to the surgeon.
An additional object is to provide a retractor which permits the degree of
retraction to be adjusted simply and quickly.
A further object of the present invention is to provide a retractor holder
which is easily moveable to a new position on the retractor frame without
the necessity of disturbing other retractor structures.
A still further object is to provide a means of preventing rotation of a
retractor holder with respect to the supporting frame.
Yet another object is to provide a retractor holder for use with retractor
frames of round cross-section which is moveable along curved sections of
that frame.
In accordance with the foregoing objects, the present invention includes a
number of improvements over conventional retractor devices.
One feature of the present invention is a retractor stem having a round
cross-section. The advantage of a round stem over a flat or other shaped
stem is that it may be rotated within the holder, thus permitting planar
adjustment of the retractor blade and increasing the range of retractor
positions available to the surgeon. Not only is this advantageous insofar
as the optimal engagement of the blade with the incision is concerned, but
it provides the further benefit of enabling the blade to be rotated away
from the patient prior to its removal from the site of the operation.
Another aspect of the invention is a retractor having an elongated stem
with a hinge disposed between the proximal handle end and the distal blade
end. The hinge permits a section of the stem of the retractor to fold down
out of the surgeon's way after the retractor blade has been drawn into the
desired position. One advantage of this folding capability is that the
surgeon's attention need not be drawn to avoiding contact with an extended
rigid retractor stem, and his freedom of movement about the operating
table can be maximized. A second, and perhaps more important, advantage is
that when a round-stemmed retractor is provided with a hinge, the folded
stem section may function as a handle by which the retractor blade may be
rotated away from the patient before its removal from the operating site.
A further improvement embodied in the present invention is an automatically
locking retractor. Automatic locking is achieved by employing a retractor
stem having a plurality of detent means disposed between the distal blade
end and the proximal handle end and a retractor holder having a pivotal
protuberance which is automatically displaceable when the retractor is
drawn away from the incision, and which prevents the retractor from moving
toward the incision by engaging selected detent means on the stem. This is
easily accomplished in accordance with the present invention by spring
loading the protuberance on the retractor holder.
The advantage to be obtained from this automatic locking capability is most
significant. Conventional retractors may only be adjusted by loosening a
nut or screw which secures the stem to the holder, moving the retractor to
the desired degree of extension, and then refastening the nut or screw in
order to secure the stem in its new position. By employing the automatic
stem locking feature however, the surgeon need only engage the blade with
the incision and then draw the stem out to the desired degree of
retraction where it will be automatically secured by the spring-loaded
protuberance of the holder without further attention. Further extension of
the retractor may easily be achieved by simply drawing the stem further
from the patient to the desired position, at which point it will again
lock in place without any additional fastening operation being required.
If a lesser degree of retraction is later desired, the protuberance on the
holder may be manually pivoted away from the stem, releasing same so that
while the protuberance remains in the manually pivoted position the blade
is free to move towards the patient to the desired position, whereby upon
releasing the protuberance, the latter will automatically engage the
detent means of the stem and again lock the retractor into position.
Also encompassed by the present invention is an improved retractor holder
having a body portion with means for attaching a retractor stem to the
holder and a clip portion for attaching the holder to a retractor frame,
in which the clip portion includes a receptacle for accommodating the
retractor frame and a resilient member in opposed relation to the
receptacle for removeably securing the retractor frame within the
receptacle. Again, great savings of time and effort result from the use of
the retractor holder of the invention, since such a clip-on holder can be
attached or removed from the retractor frame at any time and at any
position. The inconvenience of conventional slide-on holders, i.e., those
which accommodate the retractor frame within the body of the holder, is
therefore avoided, since any retractor holder attached to the retractor
frame in other than its proper sequence can easily be moved without
disturbing either other holders or the retractor frame support.
The clip-on holder of the present invention can be constructed in various
configurations so as to be adapted for use on retractor frames of various
cross-sectional shapes, such as round or flat frames. In addition, the
improved holder may be advantageously constructed with the attaching means
adjacent the resilient member such that a retractor held by the attaching
means abuts the resilient member when the resilient member is in its
undeformed position and prevents such deformation of the resilient member
which would permit the release of the holder from the retractor frame.
A further aspect of the present invention is a retractor frame having a
generally round cross-section and having an axially oriented groove. Such
a retractor frame is suited for use with a retractor holder, also within
the scope of the invention, having mounting means for accommodating a
frame of round cross-section and further having a nub on the mounting
means. When the holder is mounted on the frame the nub engages the
complemental groove of the frame, rotation of the holder on the frame is
prevented, and the retractor carried by the holder remains in a secure
vertically-stable position.
Holders adapted for use with the grooved retractor frame of the invention
may be of various configurations. For example, a solid-bodied holder
having a cylindrical passage through which the frame is inserted may be
provided with a raised ridge on the internal surface of the passage for
engaging the grooved frame. Similarly, a clip-on holder may be provided
with a protuberance, either on the interior surface of the receptacle or
on the surface of the resilient member which contacts the retractor frame.
Additionally, the grooved frame of the present invention permits the use of
both the holder of the invention and conventional holders, i.e., those
without a protuberance for locking engagement of the groove.
A still further improvement encompassed by the present invention is a
retractor holder which, in one embodiment, has a body portion and means
for mounting the holder on a round cross-sectioned retractor frame, where
the mounting means comprises a pair of spaced projections extending from
the body portion, each of the projections having a concave edge portion
for contacting the retractor frame, and a resilient member in opposed
overlying relationship to the edge portions of the projections. In an
alternative embodiment, the mounting means comprises a pair of spaced tabs
extending from the body portion, each tab having a circular aperture
through which the retractor frame may be passed. Either embodiment permits
the holder to slide around curved portions of a round cross-sectioned
retractor frame (such as a U-shaped frame), since the holder contacts the
surface of the frame at only two points, rather than along the entire
surface of the cylindrical passage of certain conventional holders. In
addition, in either embodiment, each projection or tab may be provided
with a protuberance for locking engagement with a grooved retractor frame,
thereby further augmenting its advantages.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevated perspective fragmentary view of an operating table
having attached to it a plurality of retractor frames, and, mounted on
said frames, a variety of retractors affixed with a variety of retractor
holders.
FIG. 2 is a perspective view of one of the improved retractor holders shown
in FIG. 1.
FIG. 3 is a perspective view of the retractor holder of FIG. 2 to which is
attached a retractor having a conventional flat stem and showing in
phantom lines a tubular frame on which the holder is mounted.
FIG. 4 is a sectional view taken along line 4--4 of FIG. 2.
FIG. 5 is a perspective view of a second improved retractor holder of FIG.
1 and showing in phantom lines a grooved, tubular frame on which it is
mounted.
FIG. 6 is a perspective view of a third improved retractor holder seen in
FIG. 1.
FIG. 7 is an exploded perspective view of a fourth improved retractor
holder seen in FIG. 1.
DETAILED DESCRIPTION
FIG. 1 illustrates an operating table A, having side rails B, to which
frame supports C are attached. Various types of frames 10, 11 are utilized
on which are mounted a predetermined number of retractors to be
hereinafter described. As shown in FIG. 1 the frames 10, 11 are of tubular
construction. Frame 10 is of an inverted L configuration and has the
depending leg 10a thereof connected to one of the side rails B by a
suitable clamp 13. The other leg 10b of the frame is in an elevated
position with respect to the patient lying on the table A. Frame 11, on
the other hand, has a U-shape and is disposed in an elevated, horizontal
position above the table-supported patient. The frame 11 is maintained in
the desired elevated position by a pair of upright supports 14, 15, one
disposed on each side of the table A and secured to the table frame, not
shown, by suitable clamps or the like, of conventional design. To the
upper end of each support is adjustably connected an extension arm 16 or
17. The extension arm is normally formed of conventional flat bar stock.
Once the arm has been properly positioned, it is retained in place by a
turnbolt 18 which extends through an opening in the arm and is threaded
into the end of the upright support. Both tubular frames 10, 11 are
provided with at least one exterior, longitudinally extending indentation
such as a groove 20. The groove is parallel to the axis of the tubular
frame and the function of the groove will become apparent from the
description to follow. Secured to the frames 10, 11 by various types of
holders, to be hereinafter described, are various types of retractors.
One retractor 21, shown connected to the upper leg 10b of frame 10,
includes an elongated stem 22 which is provided with a hinge 23 at
approximately mid-length thereof. The hinge 23 forms the stem 22 into an
outer section 24 and an inner section 25. Both sections are provided with
a plurality of exposed circumferential grooves G of like configuration
arranged in axially spaced relation. The hinge 23 serves a dual function:
(1) it permits the outer section 24 to assume a right angle position with
the inner section and thus, not interfere with the movements of the
surgeon and his or her assistants; and (2) when in a right angle position,
the outer section 24 provides a convenient handle to enable the retractor
to be manually rotated about the axis of the inner section 25 thereby
facilitating removal of the blade 26 from the inner end of section 25
without disturbing the patient. The shape and size of the blade 26 will
depend upon the size and location of the incision and the physical
dimensions of the patient.
As shown in FIG. 1, a second retractor of the same construction as
retractor 21 is adjustably mounted on an extension arm 27, the latter
being secured by a turnbolt 28 to the upper end of an upright support 30.
Support 30 is similar to supports 14, 15 and is secured to a side rail B
by a suitable clamp or attaching device 31. Attachment of the retractor 21
to the extension arm 27 is effected by a holder 32 which is shown more
clearly in FIG. 7. The holder 32 as illustrated includes a bifurcated
central body 33, a clip segment 34 extending laterally in one direction
from a lower segment 33a of the body 33, a thumbscrew 35 mounted on an
upper segment 33b of the body; and a stop segment 36 extending laterally
from the body lower segment 33a and in a direction opposite from that of
the clip segment 34. The clip segment includes a channel portion 37 which
is sized to accommodate a portion of the extension arm 27 as will be
described more fully hereinafter.
Overlying the body lower segment 33a, stop segment 36 and clip segment 34
is an elongated flat spring 38. The portion 38a of the spring adjacent the
stop segment is attached thereto by suitable pins or rivets 40. The
opposite end portion 38b of the spring is free and extends a short
distance beyond clip segment 34. When attaching the holder 32 on the arm
27, the spring end portion 38b is brought into engagement with an edge of
the extension arm and is distorted thereby, when manual pressure is
applied, so as to allow the arm to slide between the spring end 38b and
the clip segment 34 until it is aligned with the channel portion 37
whereupon a portion of the extension arm will be accommodated therein, see
FIG. 1. The depth of the channel portion 37 is such that when the arm 27
is accommodated therein, the spring 38 will automatically return to its
normal flat condition.
The thumbscrew 35 and flat spring 38 coact with the bifurcated central body
33 to secure an adapter piece 41 to the central body. The adapter piece
facilitates connecting the round stem section 25 of the retractor 21 to
the holder 32. As seen in FIG. 7, adapter piece 41 includes a flat base 42
which is sized so as to readily slide between the upper and lower segments
33b, 33a, respectively, of the body when thumbscrew 35 has been loosened a
predetermined amount. Once the base 41 has been secured in place by the
thumbscrew being drawn up tight against the base, the latter will overlie
a substantial portion of the spring end portion 38b and press the latter
into frictional engagement with the arm portion accommodated in the
channel portion 37 and retain the holder in a fixed, selected position on
the extension arm. An elongated depression 42a is provided in the upper
surface of base 42 which is adapted to accommodate the concealed end of
thumbscrew 35.
The base 42 has an exposed edge which is in the form of an elongated sleeve
43. The interior dimension of the sleeve permits the stem section 25 of
the retractor 21 to readily slide endwise therein. Pivotally connected to
the exterior of the sleeve and adjacent an end 43a of the sleeve furthest
removed from the retractor blade 26, is a spring-loaded latch or lever 44.
One end 44a of the latch is biased towards the sleeve axis so that it will
automatically engage one of the external grooves G formed in the stem and
restrain movement of the stem in a direction towards the patient's
incision.
The opposite end 44b of the latch 44 is in an exposed, raised position and,
when manually depressed will cause the latch to pivot about axis X thereby
releasing the latch end 44a from the stem groove allowing the stem to be
moved in either direction within the sleeve. The latch end 44b, when not
depressed, will allow the stem the patients' incision and then be
automatically locked in a desired position by the latch end 44a engaging a
stem groove G. Notwithstanding that the stem is locked in a selected
position, the retractor 21 can still be rotated about the stem section
axis by reason of latch end 44a being disposed in a circumferential
groove, thereby facilitating replacement of the blade 26 without having to
disengage the entire retractor from the holder 32 or adjusting the
position of the patient on the table A.
Locking a retractor 45 having a conventional flat elongated stem 46 on a
tubular frame 11 is accomplished by a modified form of holder 47 as seen
in FIGS. 2-4. The stem 46 normally is provided with an elongated
longitudinally extending slot 46a.
Holder 47 is provided with a center body 48, a clip segment 50 extending
laterally in one direction from a lower segment 48a of the center body. A
stop segment 51 projects laterally from the opposite side of the lower
segment 48a. It will be noted in FIG. 2 that the lower segment 48a and the
clip segment 50 include parallel side walls V and W which are
interconnected by a transverse base wall K. The portions of the side walls
constituting the clip segment 50 are provided with semi-circular cutouts
50a. The shape of the cutouts corresponds substantially to the curved
exterior of the tubular frame 11.
A flat spring 52 is secured at one end 52a by pins or rivets 53 to the stop
segment 51 and the opposite end 52b is free and overlies in spaced
relation the base wall K of the clip segment 50. As seen in FIG. 2 the
flat spring 52 is sized so as to fit between the side walls V and W.
Spaced above the flat spring and extending in a cantilever relation from
the side wall V of the center body is a flange 54 on which is mounted a
thumbscrew 55. The space between flange 54 and flat spring 52 is adapted
to accommodate the flat stem 46 of the retractor 45, see FIG. 3. Upon the
thumbscrew 55 being drawn up tight against the stem 46, the latter will
cause the free end 52b of the spring to be deflected downwardly thereby
frictionally locking the holder 47 at selected position on the tubular
frame 11. The thumbscrew 55 also locks the retractor stem in a fixed,
selected position relative to the holder 47.
Rotation of holder 47 about tubular frame 11 is prevented by providing
cutouts 50a of clip segment 50 with inwardly extending nubs 50b adapted to
engage the external groove 20 formed in the tubular frame 11.
Alternatively, the inward side of end 52b of spring 52 may be provided
with an elongated protuberance adapted to engage the external groove of
tubular frame 11 in order to prevent rotation of holder 47 about tubular
frame 11.
Holder 47 is possessed of a feature wherein it may be readily snapped onto
the tubular frame at any selected location without any adjustment of other
holders previously mounted on the frame.
FIG. 5 depicts another embodiment of a holder 56 which includes a body
section 57 having a pair of spaced, substantially parallel flange segments
57a, 57b which are interconnected at one end by a bail segment 58. Each
flange segment is provided with a substantially round opening 60 through
which a portion of the tubular frame 11 is adapted to slidably extend. A
corresponding peripheral portion of each opening is provided with an
inwardly extending nub 60a. The nubs are adapted to engage the external
groove 20 formed in the tubular frame and thus, prevent rotation of the
holder relative to the frame.
Disposed between the bail segment 58 and the flange openings 60 and affixed
to the flange segments 57a, 57b is a transversely extending anchor piece
61. Affixed to the anchor piece at approximately the mid-length thereof is
an upwardly extending stud bolt 62. The bolt terminates a substantial
distance above the upper edges of the flange segments 57a, 57b, wee FIG.
5. The stud bolt is adapted to extend through the elongated slot 46a
formed in the flat stem 46 of the retractor 45 shown in FIG. 3. The
spacing between flange segments is slightly greater than the width of the
flat stem 46 thus, enabling the flat stem to be disposed therebetween. It
will be noted that the upper edge 58a of the bail segment 58 is recessed a
slight amount from the upper edges of the flange segments The amount of
the recess is approximately the same as the distance each opening 60 is
from the upper edge of the respective flange segment.
The upper end 62a of the stud bolt is threadably engaged by a wing nut 63.
When the nut 63 is drawn up tightly against the upper surface of the flat
stem 46, the latter, in turn, will clamp the portion of the tubular frame
11 disposed within the openings 60 between the underside of the flat stem
and the lower perimetric portions of the openings. Because of the serrated
underside of the flat stem, as seen in FIG. 3 a positive non-slipping
contact is made between the stem and the tubular frame. As seen in FIG. 1,
the elongated slot 46a in the flat stem 46 of the retractor 45 is provided
with one or more enlargements 46b which will allow the wing nut 63 and end
62a of the stud bolt to pass therethrough when the wings 63a of the wing
nut are aligned with the slot.
Another embodiment of a holder 64 is shown in FIG. 6 for securing the
retractor 21 to the upper leg 10b of the tubular frame support 10, see
FIG. 1. Holder 64 is fabricated of a deformable material, preferably
aluminum, and includes a body section 65 having a cylindrical passage 65a
formed therein and disposed adjacent one side thereof. The passage 65a is
provided with a longitudinally extending key or protuberance 66. The
passage 65a is sized to slidably accommodate therein a portion of the
tubular frame support 10. The protuberance 66 is adapted to slidably
engage the external groove 20 formed in the support 10 and thus, prevent
relative rotation between the holder 64 and the frame support. A cut or
open end slot 67 is formed in the body section 65. The cut has three
exposed open sides 67a and a concealed fourth side which terminates at the
wall defining the passage 65a. Disposed transversely of the plane of cut
67 is a stud bolt 68. One end of the bolt is concealed within the body
section 65 and is anchored to the portion 65b of the body section
subtending the cut. The shank of the bolt spans the cut 67 and slidably
extends through an opening formed in the portion 65c of the body section
overlying the cut. The exposed end 68a of the bolt shank is threadably
engaged by a wing nut 70. When the nut 70 is drawn up tightly against the
exposed surface of body portion 65c the latter will be distorted
downwardly towards body portion 65b with the result that the frame support
portion accommodated in passage 65a will be fixedly held in place within
the passage.
Formed in body portion 65c and offset with respect to the bolt shank is a
second cylindrical passage 71. Passage 71 is disposed above passage 65a
and is substantially perpendicular thereto. Passage 71 is sized so as to
slidably accommodate the stem section 25 of the retractor 21. Pivotably
connected to body portion 65c and adjacent the end of passage 71 furthest
removed from the blade 26 of the retractor 21 is a spring biased latch 72.
The construction and function of latch 72 are the same as aforedescribed
with respect to the latch 44 of the adapter piece 44 of holder 32.
In holders 32 and 47, the thumbscrews thereof and in holders 56 and 64, the
wing nuts thereof cannot be disassembled from the remainder of the holder;
thus, eliminating the possibility of the thumbscrew or wing nut becoming
lost or misplaced.
From the above description, it is apparent that the objects of the present
invention have been achieved. While only certain embodiments have been set
forth, alternative embodiments and various modifications will be apparent
from the above description to those skilled in the art. These and other
alternatives are considered equivalents and within the spirit and scope of
the present invention.
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