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Full text of "USPTO Patents Application 10532180"

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10/532180 

JC1 3 Rec'd PCT/PTO 2 1 A PR 2005 

ORTHOPAEDIC RATCHETING FORCEPS 
BACKGROUND OF THE INVENTION 

[0001] The invention relates to an orthopaedic ratcheting 

forceps and specifically to a forceps used to manipulate and 
hold the bone for fixation of fractures. 

[0002] The prior art shows a multitude of manipulating 
devices for use during orthopaedic surgery. An exemplary 
forceps according to the preamble of the main claim of this 
invention is shown in WO 89/06939 (U.S. Patent No. 
4,896,661). Beside the fact of the possibility to interchange 
tips of the forceps as shown in said application, another 
important practical point for the surgeon is the possibility 
to change the attack point of the forceps, i.e., to have a 
reversible ratchet mechanism. The advantage of the ratchet 
according to said PCT application resides in the fact, as shown 
in FIG. 9, 8 and 9, that through switching a lever through 
three switching positions the forceps can move freely (Fig, 9, 
neutral position) or in either direction (FIG. 10 or FIG. 11, 
respectively) . Although this approach facilitates the work of 
the surgeon, it has been found not to be entirely satisfactory. 
The mechanism is difficult to manipulate with only one hand. 
[0003] Another known forceps is disclosed in US 5,674,244. 

The pliers according to this document have the advantage that 
almost all of the ratcheting structure is within the handles 
and do not extend beyond the outer form of the instrument. 
There is provided a spring to exert the counter-force to open 
the pliers, when the release button is pushed. The advantage of 
reduced dimensions of the forceps goes with the practical 
disadvantage in activating the locking device of the 
pliers between the handles. 
SUMMARY OF THE INVENTION 

[0004] In view of this prior art the object of the 



invention is to provide an orthopaedic ratcheting forceps for 
a surgeon giving him better control for the locking device and 
at the same time strengthen the security of the pliers. 
BRIEF DESCRIPTION OF THE DRAWINGS 

[0005] Further objects and advantages are achieved through 
the features of the subclaims and exemplary embodiments of the 
invention are disclosed in the following description in which: 
[0006] Fig.l is a view in side elevation of a forceps 

according to a first embodiment of the invention with the 
locking device in an open setting; 

[0007] FIG. 2 is an enlarged view of the lever portion 
within circle II in FIG. 1; 

[0008] FIG. 3 is an enlarged view of the locking portion 
within circle 111 in FIG. 1; 

[0009] FIG. 4 is a view in side elevation of the forceps 

according to FIG. 1 with the locking device in a closed 
setting; 

(0010) FIG. 5 is an enlarged view of the lever portion 
within circle V in FIG. 4; 

(0011) FIG. 6 is an enlarged view of the locking portion 
within circle VI in FIG. 4; 

(0012) FIG. 7 is a view in side elevation of a forceps 
according to a second embodiment of the invention with the 
locking device in an open setting; 

(0013) FIG. 8 is an enlarged view of the lever portion 
within circle VI in FIG. 7; 

(0014) FIG. 9 is an enlarged view of the locking portion 
within circle VII in FIG. 7; 

(0015) FIG. 10 is a view in side elevation of the forceps 
according to Fig, 5 with the locking device in a closed 
setting; 

(0016) FIG. 11 is an enlarged view of the lever portion 



2 



within circle IX in FIG. 10; 

(0017) FIG. 12 is an enlarged view of the locking portion 
within circle X in FIG. 10; 

(0018) FIG. 13 is a view in side elevation of a forceps 
according to a third embodiment of the invention with the 
locking device in an open setting; and 

(0019) FIG. 14 is a view in side elevation of the forceps 
according to FIG. 13 with the locking device in a closed 
setting . 

DETAILED DESCRIPTION OF THE DRAWINGS 

(0020) FIG. 1 shows a view in side elevation of a forceps 1 
according to a first embodiment of the invention with the 
locking device in an open setting, i.e., in a setting in which 
the handles 2 and 12 are freely movable about a pivot point 3. 
The forceps 1 has jaws 4 comprising sharp points provided to 
enter into bone material and/or surgical plates and bone 
material. It is clear that other configurations may be chosen, 
e.g., that the jaws comprise internal teeth. 

(0021) On the inner side of handle 2, a shaped rod 5 is 
pivotally mounted by means of a pin 6. A leaf spring 7 pushes 
the rod 5 from the outer side of the handle 2 into the 
direction or towards the pivot point 3. In a more simple 
embodiment the spring 7 may be omitted, especially if the 
guiding bore 8 (not shown) within the second handle 12 is 
sufficiently narrow. The rod 5 comprises a number of catching 
elements or ratchet teeth 10. These may comprise grooves in a 
transversal direction to the longitudinal axis of the slightly 
curved rod 5. The rod 5 is preferably slightly curved, having a 
radius of curvature equivalent to the distance from the pivot 
point 3. The grooves or notches (catching elements 10) are 
provided on the inside of the rod 5, i.e., directed towards 
the pivot point 3. 



3 



(0022) As mentioned above, within the second handle a 
guiding bore 8 is located with e.g., rectangular dimensions to 
accommodate the rectangular rod 5. If the rod 5 is more or 
less round then the guiding bore 8 may be cylindrical, or a 
rounded slit etc. 

(0023) The second handle 12 comprises a second pivot point 
13 in the neighborhood of the bore 8, dividing the handle 12 
in one fingerhole part 32 and in one jaw part 22, hinged 
together at said second pivot point 13. This allows for a 
locking structure 20 to be mounted between the first and 
second pivot points 3 and 13, respectively, of the handle 12. 
The jaw part 22 of the second handle 12, nearby the pivot 
point 13, splits of in two arms 14 and 24 between which the 
end 25 of the fingerhole part 32 is located. The two arms 14 
and 24 join together in one end point which may advantageously 
be in the vicinity of the pivot point 13. Said end 25 can be 
moved between the inner sides of the arms 14 and 24. In the 
position of FIG. 1 where end 25 is positioned toward arm 14 a 
nose 26 integrally, mounted on fingerhole handle part 32, is 
free and does not engage the catching elements 10 of rod 5. 

(0024) Between two end points (27 and here pivot point 13) 
of the arms 14 and 24, respectively, is provided a leaf spring 
28. Leaf spring 28 engages the end 25 of fingerhole part 32 
and is part of the lever and locking mechanism of the 
ratchet. In the preferred embodiment, spring 25 is made of 
spring steel and supplies sufficient force to maintain the 
nose 2 6 into engagement with the teeth of arm 5 when deflected 
towards arm 24. 

(0025) FIG. 2 is an enlarged view of the lever portion 

within circle II in FIG. 1. Same features in all drawings 

always have the same reference numerals. Spring 28 is mounted 

with the transversal direction of the leaf perpendicular to 

the drawing plane and therefore parallel to the axes of the 

4 



pivot points 3 and 13. Therefore two noses 29 provided 
parallel one to another and encompassing the leaf spring 28 
are mounted on the end 2 5 and extending into the space 
between the arms 14 and 2 4 provide guiding means for the 
spring 28. Since the spring 28 is biased, i.e., longer than 
the length of a direct fine between the end points 27 and 13 
of the arms 14 and 24, the end 25 can only take two stable 
positions, one open setting according to FIG. 1 (deflected 
towards arm 14) and one closed setting according to FIG. 3 
(deflected towards arm 24) . The noses 29 may be small bolts or 
cylinders with enough play between them to allow the movement 
of the spring 28, the surface of the bolts 29 on the opposite 
side to the position of the spring 28 can be directly used to 
abut against the arm 14 or arm 24, respectively, 

(0026) FIG. 3 is an enlarged view of the locker portion 
within circle III in FIG. 1. The teeth 10 comprise two 
different slopes 70, 71. Slope 71, which is the slope 
oriented towards fixation point 6, is more or less 
perpendicular to the current longitudinal axis of rod S. The 
other slope 70 is inclined in direction of fixation point 6 
with an angle between preferably 30 and 60 degrees in 
comparison to the direction of slope 71. 

(0027) FIG. 4 shows a view in side elevation of the forceps 

1 according to FIG. 1 with the locking device in a closed 

setting, i.e., in a setting in which the handles 2 and 12 

are only movable about the pivot point 3 in a direction 

closing the jaws 4 of the forceps 1. FIG. 5 is an enlarged 

view of the lever portion within circle V in FIG. 4. As can be 

seen in comparison of the two settings of the forceps in 

FIG. 1 and 4, the handles 2 and 12 are freely movable (i.e., 

they can be opened) . There can be an additional spring, not 

shown in FIG. 1 and 4, between handles 2 and 12 in the 

vicinity of pivot point 3, urging the handles 2 and 12 apart. 

5 



otherwise (without said spring) the forceps may be opened by 
the surgeon as he would do with scissors. Upon pushing the 
handle 12 and especially the fingerhole part 32 towards the 
other 5 fingerhole part 42, a moment is exerted upon the 
spring 28 through the lever provided through second pivot 
point 13 and the lever length to the end 25, This moment 
pushes the spring 28 out of the stable open setting as shown 
in FIG. 1 towards the second stable setting as shown in 
FIG. 4, the closed setting. Through the movement of the 
fingerhole part 32 relative to the jaws part 22 of the handle 
21 the nose 2 6 engages one of the catching elements 10 of rod 
5. Therefore upon releasing the fingerhole parts 32 and 42, a 
counter pressure upon the jaws 4 of forceps 1 will not open 
the handles 2 and 12 because the forceps 1 is in a stable 
closed setting- However, the surgeon has the possibility to 
further close the fingerhole parts 32 and 42. To ensure the 
possibility of this movement the catching elements 10 of rod 5 
and the nose 26 are formed asymmetrically, ensuring that the 
nose 26 can glide from one catching element 10 to the next one 
which is nearer to the pivot point 6 while forbidding the 
inverse movement . 

(0028) The surgeon can also very easily release the grip of 
the forceps through pushing the fingerhole 32 apart from the 
fingerhole 42, disengaging the nose 26 from the catching 
elements 10, when the setting according to FIG. 1 is reached. 
This means that he controls the opening and closing of the 
forceps 1 through simple manipulation and relative movement of 
the fingerhole parts 32 and 42. There is no need for a 
separate switch, button or release mechanism. 

(0029) FIG. 6 is an enlarged view of the locker portion 

within circle VI in FIG. 4. Two teeth 10 with their two 

neighbouring different slopes 70, 71 are in engagement with 

the nose 26, which preferably has a complementary form to the 

6 



groove 72 which is formed by the slopes of adjacent teeth 10, 
therefore blocking the movement of the rod 5 in one direction 
and allowing said movement 4 0 in the other direction. 

(0030) The embodiment according to FIGS. 1 to 4 is not the 
only possibility to achieve such advantageous handling of a 
forceps. FIG. 7 is a view in side elevation of a forceps 41 
according to a second embodiment of the invention with the 
locking device in an open setting. All features within the 
embodiment of FIG. 7 having similar features within the 
embodiment according to FIG. 1 have the same reference 
numerals. FIG. 8 show an enlarged view of the lever portion 
within circle VI in FIG. 7 and FIG. 9 is an enlarged view of 
the locking portion within circle VII in FIG. 7. Within this 
embodiment a release button 42 is provided in parallel to one 
handle 12. The principle of the forceps 41 is as follows. A 
cylindrical locking element 35 is provided on or integral to 
handle 2. This locking element 35 comprises at least a rough 
surface, preferably comprising small transversal grooves 36. A 
complementary locking element 37 is provided with the release 
button 42 being realised as a lever arm extending in parallel 
to handle 12. The complementary locking element 37 comprises 
grooves or teeth 36 which are arranged along a curve with a 
changing curvature, i.e., the radius of curvature becomes 
greater between the position of the element 37 which is named 
the open setting in relationship to the position which is 
named the closed setting. 

(0031) The open setting of FIG. 7 is achieved through a 

biased spring 28 extending between one end point 27 inside a 

lengthy slit between two webs 14' and 24' and another endpoint 

57 near the pivoting point 33. In order to achieve the closed 

setting as shown in FIG. 10 showing a view in side elevation 

of the forceps 41 according to FIG. 7 with the locking device 

in an closed setting, and as the detailed view of FIG. 11> an 

7 



enlarged view of the lever portion within circle IX in 
FIG. 10, and FIG, 12, an enlarged view of the locking portion 
within circle X in FIG. 10. Through a pivoting of the lever 42 
away from the handle 12 the two complementary surfaces 35 and 
37 mutually engage and through the special form of the surface 
37 the forceps 41 can not open anymore since the spring 2 8 now 
urges the lever 42 in the second stable setting, the closed 
setting . 

(0032) Finally FIG. 13 shows a view in side elevation of a 

forceps 61 according to a third embodiment of the invention 
with the locking device in an open setting, and FIG. 14 shows a 
view in side elevation of the forceps 61 according to FIG. 13 
with the locking device in a closed setting. 

(0033) On the inner side of handle 2, a shaped rod 5 is 

swivel-mounted by means of a pin 6. The guiding bore 8 within 

the second handle 12 accepts the rod 5. The rod 5 comprises a 

number of catching elements 50. These may comprise grooves in 

a transversal direction to the longitudinal axis of the 

slightly curved rod 5. The rod 5 is preferably slightly curved, 

having a radius of curvature equivalent to the distance from 

the pivot point 3. The grooves or notches (catching elements 

10) are provided on the insid|e of the rod 5, i.e., directed 

towards the pivot point 3. Within the second handle 12 is 

located a bolt 48, which is pushed in direction of the rod 5 

through a spring 47 which may be a disk spring and which is 

placed in the second handle 12 between the bolt 48 and the 

pivot point 3 acts to move surface 4 6 of rod 5 towards surface 

46 of an element 37. In the open setting shown in FIG. 13 the 

surfaces 4 6 of element 37 and rod 5 are not in engagement, 

whereas in FIG. 14 the element 37 is pushed inside the 

forceps 61 therefore bringing the surfaces 4 6 in contact one 

to another achieving the same function as within the second 

embodiment, i.e., preventing the jaws 4 from opening but 

8 



allowing closure. The arrangement according to FIG. 13 and 12 
allows a further compression, just gliding the surfaces 4 6 one 
against another. However, there is no backwards travel, which 
can only be achieved through pushing the element 37 towards 
the outside through pushing the nose 4 9 in either direction 
(from FIG. 13 to FIG. 14 and vice versa) . 

(0034) In all embodiments the release or fixation element 
is directly usable when gripping the forceps, either through 
manipulation within the fingerholes 32 as in the first 
embodiment, or through a release lever 42 in parallel to the 
handle as in the second embodiment, or through a bolt 48 
releasing element, provided in parallel to the second handle 
as in the third embodiment. 

(0035) One of the advantages of the embodiment according • to 
FIG. 1 is the possibility to switch from the open to the closed 
setting through movement of the handles. There is no 
additional button or lever to be manipulated. Therefore the 
surgeon can switch the device into the closed setting, engage 
the device within the body to be gripped, close the jaws 4 
further, while within this closed setting the surgeon is sure 
that one position of the jaws reached they will not open any 
more. If now the grip has to be loosened, the surgeon can 
switch from the closed setting to the open setting without 
leaving the gripping holes of the handles. Then he opens the 
jaws and continues to work on the same body to be gripped or 
another without loosing time. 

(0036) The second advantage of the embodiment shown in 

FIG. 7 to 10 is the reduced space requirement and the button 

49 is still easily reached since mounted in a natural position 

for the hand. This result can be reached through the 

definition of the surfaces 36 within the elements 35 and 37, 

respectively. In the figures one element has a cylindrical 

curvature while the other has a changing radius of curvature. 

9 



In the open setting (freely movable jaws 4) the two elements 
are in a small distance one from another when the distance is 
measured on the straight line between the two axes. When the 
button 42 is moved to the closed setting, the element 37 is 
rotated around the axis 33. Therefore the distance changes 
and eventually becomes zero. The surfaces 36 are engaging one 
another. When the surgeon now would try to open the jaws, 
i.e., move the second handle 2 away from the first handle 12, 
the two surfaces would rotate around the axes 33 and 3, 
respectively. But this rotation would diminish further the 
distance between said surfaces since one of the elements has a 
growing radius of curvature in this direction of rotation 
resulting in a blocking state. The further closing of the 
jaws through movement of the handles would move the elements 
in a direction where at least one element has a diminishing 
radius of curvature thus allowing this movement. 
(0037) In order to ensure the best engagement of the 

surfaces they are provided with microgrooves or grooves in a 
direction perpendicular to the drawing sheets. 

559493_I.DOC 



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