Surgical stapler

A surgical stapler having a pivotable trigger in a housing and a cartridge of surgical staples, has a moving anvil which receives one staple at a time in its open configuration. A forming blade moves to engage and capture the staple between the forming blade and the anvil and drive the staple away from the cartridge allowing the user to see and place the points of the staple at a desired location on the tissue. Further movement of the forming blade pressing upon the top of the staple forces the staple legs to pierce and close joining adjacent edges of tissue. First and second stripper elements acting separately or in combination engage and urge the closed staple to separate from the anvil.

BACKGROUND OF THE INVENTION 
This invention is in the field of surgical staples and surgical staple guns 
for implanting such staples. A very large number of surgical stapler 
devices have been made in the last few years by a growing number of 
manufacturers; however, in all cases the staples used were essentially 
conventional stainless steel or equivalent staples, generally similar to 
those used for stationery products, other packaging or joining equipment. 
More particularly such staples are preformed in a wide open condition with 
legs of the staple directed parallel and downward from a top arch or 
crossbar to grasp adjacent edges of an incision for closure. These staples 
are contained in a magazine, and each is released one at a time and moved 
laterally forward to a fixed anvil which supports the underside of the 
crossbar while its sharply pointed ends engage and pierce tissue and are 
forcibly bent to close about and capture the edges of the juxtaposed 
tissue. 
In typical prior art staplers the staple is forced from a generally 
rectangular configuration to generally closed rectangular configuration by 
applying force at two points on the top side of the staple while 
restraining it inbetween these points. The term anvil is used because the 
staple is closed by forcing the legs against a fixed, rigid anvil-like 
support within or near the surface of the stapler's housing. Such 
substantial forces are required that the support anvil is traditionally a 
fixed portion of the housing, which thus results in the staple being 
implanted and closed while its upper arch part remains in the stapler. 
This arrangement obviously has a limiting effect on the surgeon's ability 
to see the stapler and the wound. 
In addition to the visibility limitation due to the location of the staple 
partially within the device during closure, the prior art devices are 
relatively large to begin with which is another inherent visibility 
obstacle. The width dimension of the prior art housing, for example, must 
be at least equal to the width of a staple in its fully open configuration 
in the staple magazine, plus housing thickness and clearance, this total 
width dimension being significantly greater than the width of a staple in 
closed configuration. 
SUMMARY OF THE INVENTION 
This invention is a new surgical staple and a stapler designed to deliver 
and implant a plurality of staples, one at a time into a patient's tissue, 
specifically to engage adjacent edges of an incision or wound and close in 
a manner to hold together these edges. The staples typically made of 
stainless steel define a wide angular C-shape with two sharply pointed 
ends directed generally downward and inclined slightly toward each other 
when the staple is in open condition. When closed each staple has a 
generally rectangular shape with the legs directed at each other and 
optionally inclined slightly upward to provide a highly secure closure. 
Principal objectives in the present invention are to provide an apparatus 
which is extremely simple and reliable in operation, one which is simple 
and inexpensive to manufacture by having the fewest possible parts that 
can be assembled rapidly, and, furthermore, one which provides high 
visibility in the area of the staple discharge from the gun so the surgeon 
can see the staple as he positions it prior to closure and during closure. 
The new device closes each staple with ample force to pierce skin 
consistently and reliably, yet requires less force by hand to do so. When 
closed the staple has its pointed ends either slightly upward or overlying 
or at least very close together. Also the invention includes a "feelable" 
pre-cock position at which point a detent engages and prevents return of 
the trigger. The surgeon can release his hand while the staple is held in 
its pre-cock position. Furthermore, the device has a non-directional 
staple release function; accordingly there is no need to move the gun 
forward, backward, upward or downward to effect release of the closed 
staple from the gun. 
Basically, this surgical stapler is a hand device with a handle part which 
is gripped in the surgeon's palm and a pivotal or otherwise movable 
trigger part which is moved when squeezed by the surgeon's fingers against 
the adjacent handle. The trigger is an elongated element with a pivot 
point close to the front end so that movement of one end causes opposite 
motion of the remote end. A mainspring is situated in the housing to urge 
a forming element upward to bear against and urge the trigger to a 
clockwise or open position within the handle. Within the stapler the 
trigger, driven by the surgeon's hand, is the basic power source which is 
transmitted through various components to deliver and close each staple. 
Also inside the device is a magazine containing a plurality of staples 
arranged in a generally traditional manner, aligned on a magazine mandrel 
or core and urged by independent spring means to slide along and then off 
the mandrel one at a time. Obviously, the device allows only the outermost 
staple to be discharged to a descending anvil and driver element for 
descent to the discharge area below the cartridge where the staple is 
closed. The driver or forming blade and moving anvil comprise a 
sub-assembly for engaging, stabilizing, restraining, delivering the staple 
to a lower level, closing and finally releasing the staple. An objective 
is for the separation of the staple from the staple gun to occur easily, 
quickly and smoothly without further movement of the gun relative to the 
wound and without chance of the staple "hanging-up" in the gun. When so 
closed and released the staple is outside of and partially or totally 
below the cartridge or magazine and lower portion of the gun. 
In our preferred embodiment the new staples are stored in the cartridge in 
the stapler in partially closed state; the resulting housing thus occupies 
less width than prior art housings and thus provides improved visibility 
at the closure area. The staple is delivered to a point below the 
cartridge that is preferably tapered and narrower than the open staple 
itself; this feature obviously maximizes visibility. 
In the new stapler means are provided on the forming blade for preventing 
the staple from tipping and rolling out of its generally vertical plane. 
Associated with the forming blade are stripper means for stripping or 
prying a closed staple off of the anvil so that the stapler device can be 
easily and smoothly separation from the closed and emplaced staple. 
It should be noted that the design of this stapler requires that the 
trigger be squeezed from open to closed position through a series of 
phases during which the staple goes through its complete cycle of: 
engagement, descent, pre-cock, tissue engagement, pierce tissue of opposed 
edges of the incision, close, and finally separate from the gun. It is the 
intent herein that the gun and its trigger move in one consistent 
direction during the entire staple formation and movement phase. This is 
logically consistent, adds to overall simplicity of the device, and is 
helpful psychologically for the user to have a trigger moving in only one 
direction to complete all phases of the staple manipulation to close. This 
"forward" motion is reversible until the pre-cock position is reached. 
By having the staple positioned below the cartridge and in front of the 
tapered housing, the surgeon can clearly see precisely where the pointed 
ends of the legs of the staple will be engaged in the tissue. Not only 
does the new device permit these totally new and novel operations with 
staples, it does so with the highest visibility ever achieved because the 
staple, during these moments of final decision, is fully exposed and 
essentially out of the stapler while it is held by the staple engaging 
means. 
A further feature of one embodiment of this device is the incline of the 
staple magazine so that the lower housing will be smaller and allow for 
greater visibility. As generally indicated, the magazine is aligned along 
an axis that defines an angle less than 90.degree. with the line of 
descent of the staple driver. It has been found possible to incline the 
line of descent of the staples relative to the magazine. 
In a preferred embodiment the drive system for engaging, transporting, 
closing and releasing each staple is basically a handle or trigger with a 
pivot point nearer to one end such that an approximately 3 to 1 leverage 
ratio is established, and so that a 20.degree. pivot movement of the 
trigger's near end by the surgeon's hand will cause the remote end by 
direct linkage to actuate and drive the remaining components. Alternative 
drive mechanisms could include gear trains and cam-follower arrangements 
for producing linear movement of the staple driver from pivoting or other 
movement of the surgeon's hand. 
As described generally above, each staple goes through engagement, descent, 
closing and release. In a cam drive system, different cams can easily 
accomodate these different take-offs while the trigger is pivoted smoothly 
and/or continuously. In direct drive mechanisms means are provided to 
allow the trigger's continuous pivoting to cause staple-engaging and 
forming means to first drive a staple downward from the magazine, and then 
to close and release the staple. Closing of the staple while it remains at 
a lower elevation requires an "idling" phase of the anvil while the 
trigger continues moving. This is accomplished in one embodiment by using 
relatively soft and hard springs axially, the latter not moving until the 
former is fully compressed. 
A variety of other and specific features are disclosed in the detailed 
drawings and descriptions that follow of preferred embodiments of carrying 
out the principles of this new stapler invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The new surgical stapler is illustrated in FIG. 1 showing an assembled 
device and in FIG. 2 which is an exploded view showing its various 
principal components. As illustrated in these figures the stapler assembly 
10 has a casing 12 with a trigger 14 which is pivotable within the casing 
about pivot 16, and a detent 15a engagable with abutment 15 to provide an 
audible and/or physical indication that closure of a staple is imminent 
and to prevent reversibility once engaged. At the front of the stapler is 
a front cover portion of the case 18 in the area where staples are 
discharged one at a time. A cartridge assembly or magazine 30 holds a 
plurality of staples 34x on a mandrel 32; a pusher 36 driven by a pusher 
spring 38 urges the staples toward the left as shown. The magazine is 
inserted into the stapler casing with staples at the front end 33 of the 
mandrel 32 situated near the front opening 31b of the casing. The lead 
staple 34a of the plurality of aligned staples 34x would be pushed outward 
into the staple-forming sub-assembly. Generally stated, one staple at a 
time is discharged into the forming blade anvil sub-assembly which, upon 
squeezing of the handle, then lowers the staple below the lower front part 
of the casing. Further squeezing of the handle closes the staple and 
finally releases the staple from the device, all these phases being 
illustrated schematically step-by-step in FIGS. 3 and 4. 
The staple-forming sub-assembly as seen in FIGS. 2, 8, FIGS. 17, 17e, 
comprises the anvil 20 for receiving the lead staple, and the forming 
blade 24 for driving the staple downward and closing the staple. Anvil 
spring 26 urges the anvil to its normally upward position, and forming 
blade spring 28 urges the forming blade also upward relative to the anvil 
and relative to the casing. An additional feature, particularly shown in 
FIGS. 17c-17e in the stripper 130 portion of the forming blade which 
strips or separates a closed staple from the staple-forming subassembly, 
so that the stapler can be removed from such closed staple which is 
embedded in a patient's tissue. 
The lead staple 34a in the staple magazine is received upon the lower lip 
20t of the anvil 20 and subsequently held between said lip and the bottom 
edge of the forming blade 24. Next the forming blade is driven downward 
against the top of the staple's crossbar or arch, which along with the 
anvil is pushed downward until the anvil is stopped and the forming blade 
continues its descent relative to the staple which is supported in place 
by the anvil. As a result, the forming blade forces the partially open leg 
parts of the staple to be closed for joining and holding adjacent edges of 
the tissue. 
In the cartridge or magazine assembly 30 illustrated in FIG. 2 the staples 
34x and pusher 36 slide along the top of mandrel 32 while spring 38 is 
situated with its ends 38a secured to the front of the mandrel and its 
mid-part positioned to engage the rear side of the pusher's upward 
extending tab 37. This spring is preferably a Negator spring applying 
constant tension regardless of the amount of extension of the spring which 
will vary depending on the number of staples remaining in the cartridge, 
to urge the staples off the mandrel in a direction toward the left as 
shown. The pusher 36 has its own tang (not shown) which projects outward 
through the housing; the position of this tang indicates the axial 
position of the pusher and thus the approximate number of staples 
remaining in the magazine. 
The operational phases of the staple-forming assembly are shown 
schematically in FIGS. 3, 4 and 4a. The phases are designated 1, 2, 3, 4, 
and 4a, after which the cycle is repeated as indicated by phase 5. Phase 
4A is shown for the strip-off operation wherein the staple is separated 
from the device. FIG. 3 is a schematic view showing all the principal 
elements at once which are indicated by reference numerals corresponding 
to those in the exploded view of FIG. 2 and also at times by suggestive 
initials. Accordingly, in FIG. 3 there is shown the forming blade FB or 
24, the anvil A or 20, the staple 34, the forming blade spring 28, and the 
anvil spring 26. Also there is an anvil upper stop 40a and lower stop 40b 
and a forming blade upper stop 42, and the anvil's lower tab 20t for 
receiving and engaging the lead staple from the cartridge. For convenience 
of references the anvil's upper stop 40a will also be designated as a 
basic starting reference plane R as a starting plane for the phases. In 
both FIGS. 3 and 4 the phases are designated 1-4a moving downward from top 
to bottom. 
In FIG. 4 the activities of FIG. 3 have been separated into two columns A 
and C. More particularly, column A illustrates mainly the anvil A and 
staple 34 as they progress through the five stages; and column C 
illustrates the forming blade FB and staple 34 as they progress through 
the stages. In column A the anvil has its upper stop at reference plane R1 
and a lower stop; in column C the forming blade has its upper position at 
reference plane R2. At positions 2, 3, and 4 the anvil and forming blade 
have descended downward from their reference planes by distances 
corresponding to changes and locations of the staple. 
Beginning with phase or position 1 seen in FIGS. 3 and 4 and 4a, the 
engaged staple 34 is aligned with the lip or lower tab 20t of the anvil, 
this staple having been automatically driven laterally into this position 
by the spring 38 of the magazine (not shown). In moving from position 1 to 
position 2 the forming blade FB descends slightly to engage the top of the 
staple's crossbar while the bottom of the staple's crossbar is supported 
by the anvil's lower lip 20t. Subsequent downward movement by the forming 
blade will then be positively transferred by solid contact from the 
forming blade to the staple and the engaged anvil, thus moving all three 
parts simultaneously. FIGS. 4a and 4b correspond to FIG. 4 (column A) and 
FIG. 4 (column C) respectively and provide another perspective of the 
forming blade-anvil-staple relationship by illustrating a lateral spread 
of the relative elevation of these elements. During the succession of 
phases 1-4a discussed above, FIGS. 4a and 4b show the incremental 
distances moved by the anvil and forming blade between phases, while FIG. 
4 shows the cumulative distances moved from the initial reference planes 
R1 and R2 by these elements. 
By appropriate designs of the springs 26 and 28, as seen in FIGS. 2, 3, and 
14, the anvil is urged by spring 26 upward at all times relative to the 
casing, but is also urged toward the forming blade, and a separate spring 
28 separates the forming blade from the anvil. When the operation of the 
stapler device proceeds from position 1 to 2 the staple is captured by 
virtue of the force of the forming blade applied toward the anvil which 
effectively sandwiches the staple therebetween, and thus captures it and 
prevents it from moving out of position or otherwise becoming displaced. 
The design of the springs is intended to produce about one pound of upward 
force between the anvil and the staple pushing up while the forming blade 
is correspondingly pushing down to thus securely hold the staple. It is 
intended for these elements to be loaded or preloaded in such a way that 
there is a net "up" force on the anvil, and that in the fully down 
position there will be sufficient "up" force to pull the forming blade off 
the staple and overcome the friction between the bottom of the forming 
blade and the top of the staple resulting after the staple has been bent 
into a closed position. If there isn't enough force urging the forming 
blade upward, i.e., if the spring is too soft, then there could be a 
hangup and the forming blade would in effect stick to the top of the 
staple and anvil and thus not rise. 
A further review of FIGS. 3 and 4 will add certain perspective to the 
entire process. In FIG. 4, columns A and C the staple is shown initially 
in its partially closed position which is its shape as aligned on the 
mandrel in the cartridge 30 of FIG. 2. In phase 2 the forming blade 
descends slightly as indicated by the 0.027 inches. In position 3 the 
staple, while still open, has been pushed all the way down because the 
anvil has hit its lower stop 40b and the staple captured by the lower lip 
20t of the anvil cannot descend any farther anyway. At position 4 the 
staple has been closed, and in position 4a the stripper, as further 
described below, strips the closed staple from the anvil, although the 
various elements are at the same elevation as before. At position 5 the 
anvil has ascended back to the original position leaving the staple closed 
and embedded in tissue; position 5 corresponds to position 1 so that the 
next lead staple will automatically be driven onto the anvil's lip 20t. 
Column C illustrates how the forming blade moves downward from its 
reference level R2 in position 1. At position 2 the forming blade has 
moved an amount indicated 0.027 inches as shown in the drawing. At 
position 3 the forming blade is down 0.427 inches, at position 4 the 
forming blade has been driven another 0.08 inches to 0.507 inches in order 
to close the staple as shown, and by position 5 the forming blade has 
risen back to its reference position R2. 
The basic concept as described earlier includes use of a staple magazine or 
cartridge within the stapler housing where the magazine holds a plurality 
of staples in partially closed condition; one staple at a time it taken 
off the magazine, carried downward outside of the housing, caused to have 
its pointed ends pierce tissue, forced to bend to its closed condition, 
thereby being inserted in and gripping the tissue, and finally released 
from the stapler device. 
In the preferred embodiment, a particular staple construction is used along 
with a staple delivery system as follows. FIG. 6 illustrates new staple 50 
whose cross-section seen in FIG. 9 is essentially round along its full 
length, i.e., along the crossarm or arch 50a, the sides 50b, and the legs 
50c, except for the points 50d. The points 50d. are cut, sheared or ground 
at an angle of approximately 30.degree. to insure maximum point sharpness. 
In the preferred embodiment the dimensions referred to in FIGS. 5-9 are 
W1=0.555", 0=25.degree., W2=0.25" r=0.03", H1=0.173". 
In the staple magazine the staples are aligned on a mandrel generally in 
the partially closed position seen in FIGS. 2, 6 and 17a which results in 
a delivery system being narrower than conventional systems, thereby 
contributing to improved visibility for the surgeon. As evident in FIG. 6 
there is a gap 51 between the points 50d of the staple to allow a blade or 
stem of the mandrel to extend downward through the gap and be secured to 
the remaining part of the magazine. 
FIGS. 2, 8, 17 and 17b illustrate the staple magazine and its operation. 
The mandrel 32 has an upper housing 32A with inner grooved surface 32b 
which helps guide the line of staples. The top surface 32c of the mandrel 
similarly guide the bottom and inner surface of the line of staples. As 
drawn the staples hang generally vertically relative to the inclined 
mandrel, and the lead staple 34A exits the mandrel off generally 
horizontal lip 32d and onto anvil lip 20t. 
FIGS. 11, 17, 17a-17, 19 and 19a further illustrate the staple delivery 
sub-assembly comprising the anvil 20 and the forming blade 24 in their 
relative positions. The anvil 20 has a generally vertical blade part with 
a lower lip 20t projecting rearwardly from the anvil blade into the plane 
of a staple 34. The anvil moves between upper and lower stops respectively 
fixed to the stapler housing as indicated in FIGS. 3 and 4. In the upper 
position the lower lip 20t of the anvil is positioned directly below the 
staple's crossarm or arch 34b as seen in FIG. 17b. An anvil return spring 
36 urges the anvil toward its upward position against stop until the anvil 
is driven down in the staple delivery cycle. 
When the anvil is stopped by the lower anvil stop, the forming blade 
overrides the interposed spring 28 and forces the staple sides or top part 
to bend around the ends of the anvil lip 20t and forces the legs downward 
to pierce the skin. The spring 28, interposed between portions of the 
anvil and forming blade, serves as a return spring for the forming blade 
urging it upward, as well as being an override spring which allows the 
forming blade to continue moving downward after the anvil 20 has moved to 
its lower position where its movement is restrained by the second or lower 
anvil stop. 
FIG. 14 illustrates generally the stapler housing 12 in which the trigger 
14 pivots about axis 14a. The trigger is pivoted by squeezing its gripping 
surface 14b, thus driving it in a counterclockwise direction and thereby 
urging its front end 14c to drive the forming blade 24 downward. As shown, 
the anvil return spring 26 is stronger than interposed spring 28 between 
the forming blade and the anvil. Accordingly, pivoting of the trigger will 
cause the forming blade alone to descend initially; thereafter the forming 
blade and anvil will descend together, but by then the staple will be 
positively captured between them. At the bottom of the anvil's stroke, 
when it hits its stop, the forming blade will then be driven further, 
overcoming its own return spring 28 as the staple is closed. The pivot 
point 14a of the trigger is situated much closer to the forming end 14c of 
the trigger than the hand end 14b, thus providing a ratio greater than 
unity and a force advantage that allows the surgeon to deliver and form a 
staple with only a moderate amount of effort applied by his hand and 
fingers to the stapler handle. FIG. 14 also shows symbolically the staple 
cartridge 79 positioned to deliver one staple at a time to the anvil. The 
last few degrees of motion of the forming blade cause the staple to be 
stripped. 
The actual closing of the staple by bending the opposite legs is 
illustrated in FIGS. 19 and 20 as follows. When the staple is closed 
deformation occurs in the area marked "e" essentially because the anvil 
has a transverse dimension, in this case 0.210 inches which is 
substantially less than the original length of the horizontal crossarm 50a 
of the staple. During closure of the staple in the course of surgical 
insertion, the staple is closed by the forming blade which changes the 
staple from that shown in FIG. 6 to FIG. 7. The space on each side between 
the edge 120 of the anvil (FIGS. 19 and 20) and the adjacent inner edge 
121 of the forming blade tang results in a gap within which the staple is 
bent. This gap, f in FIG. 20, is larger than the thickness of the staple 
t; in the embodiment shown f=1.2t. The dimension f is significant because 
it represents the space allowed for the bent staple to exist; the more the 
staple is bent, the greater will be the friction between the two edges 
defining dimension f, and the more difficult it will be to effect closure 
and also the more difficult it will be to lift the forming blade away from 
and disengage from the staple which will be trapped between it and the 
anvil. 
The prior art surgical staplers require approximately 55 lbs. of force to 
effect the bending because they have to bend essentially 90.degree., and 
this necessarily means that dimension f will be very small, in fact less 
than t, and the friction will be extremely high. In the present invention 
the force of only 18 pounds is required to achieve full closure or even to 
achieve overcrimping, i.e., closure until the staple legs are bent to the 
orientation illustrated in FIGS. 7 or 20. 
FIG. 19 illustrates a staple in its initial open phase 1 and an 
intermediate bent stage; FIG. 20 shows the staple in its final closed 
phase 4a. Also shown are the corresponding position of the forming blade 
the groove 132 in the forming blade which engages and guides the staple 
from tipping or rolling. 
As the forming blade bends the staple around the corner of the anvil, the 
section of the staple between the corner of the anvil and the upper staple 
(Section a--a FIG. 20) corner rotates through an angle shown in FIGS. 19 
and 20. Due to the angle (see FIG. 6) between this section and the lower 
leg of the staple, the lower leg is rotated approximately 25 degrees ahead 
of the section a--a (see FIG. 20). Thus, to force the point of the staple 
to rotate to a horizontal attitude requires a rotation of less than 
90.degree. of the staple leg. A rotation of approximately 65 degrees will 
result in horizontal staple points, thus the dimension f in FIG. 20, which 
for a conventional stapler must be no wider than the wire thickness to 
ensure full rotation of the point, in this invention can be larger than 
the wire thickness (typically 1.2t). This results in a substantial 
reduction in the force required to close the staple which has important 
ramifications in other areas of the design. By reducing the dimension f, 
the points of the staple when fully closed can be made to touch or cross 
providing overcrimp which significantly improves the staple's reliability 
of piercing the skin and thereafter remaining securely emplaced. Overcrimp 
means a staple configuration wherein the staple ends point slightly upward 
or overlie each other rather than merely point co-axially at each other 
while separated. 
FIG. 11 is a sectional view corresponding to FIGS. 17 and 19a, showing the 
lateral relationship of the anvil, forming blade and front edge 18 of the 
housing. In FIG. 19a the anvil lip 20t has width WA; W is the width of the 
open staple; WP is the width between staple points; d is the staple wire 
diameter; and 1.2 d is the gap between the anvil lip edge and the wall of 
the notch of the forming blade. Upon descent of the forming blade the 
staple is bent and the staple legs lie in the gap space. 
The previously described detent and spring clip combination 15, 15a or 
equivalent device, provides an audible and/or physical indication that 
handle movement has progressed a predetermined amount and the staple is in 
its lowest position ready for final closure. A second audible signal may 
be provided and indicate that closure has occurred, i.e., that the staple 
is fully closed and released from the device. Accordingly, with this 
feature the surgeon will know when he can still release the handle, return 
the staple to the gun and attend to other matters prior to re-using. To an 
extent this apparatus is reversible in that the springs within the housing 
urge the pivoted handle to return to its open position. 
The stripper feature referred to earlier allows smooth and quick separation 
of the stapler from a staple after closure is complete and the staple legs 
are embedded in a patient's tissue. As indicated in FIGS. 3 and 4 
stripping occurs between phases 4 to 4a, whereby the staple's crossbar is 
cammed off the anvil's lip. Details of the stripper are seen in FIGS. 
17c-17f wherein the forming blade's lower edge 130 is bevelled about 
30.degree., while adjacent outer parts 132 are grooved concavely. During 
initial phases of closure the forming blade's grooved edges 132 engage and 
partially capture the top outer edge of the staple's crossbar, such 
capture preventing the staple from "rolling" out of its essentially 
vertical plane. Rolling or tipping of the staple is not uncommon in prior 
art staples when the staple points meet resistance to penetration or when 
the user inadvertently moves the stapler transversely off the plane of the 
staple while the points have penetrated tissue and the crossbar is still 
secured to the anvil. 
After forcible descent of the forming blade relative to the anvil causing 
full closure of the staple's legs, slight additional trigger movement 
causes final descent of the forming blade relative to the anvil whereby 
the bevelled edge 130 in FIGS. 17e and 17f cams the staple's crossbar 134 
off the anvil's supporting lip 136. This simple finger movement on the 
trigger affects full release of the staple with no requirement of the 
surgeon moving his hand or the stapler laterally forward or backward and 
no danger of the staple being "hung-up" or otherwise stuck in the stapler. 
The stripper action also assures separation despite any tendency of the 
staple to remain engaged to adjacent edges 121 of the forming blade which 
previously forced the staple into its final configuration, especially 
after release of the handle. The exact angle of the bevelled edge 121 may 
vary depending on the diameter and cross-section of the staple's crossbar, 
and the amount of trigger motion one desires for stripping versus the 
speed of stripping, a greater angle obviously requirement more motion but 
less force. 
A further embodiment of the stripper is shown in FIGS. 21-25. Here the 
forming blade 150 has the stripper bevel 152 for camming the closed 
staple's crossbar 154 off the lip 153 of the anvil 155, as generally 
described earlier, and a pair of angled release surfaces 156 for camming 
or nudging the elbows 158 of a closed staple. Surfaces 156 are located a 
distance K in FIG. 22 from bevel 152 which corresponds to the distance K' 
between the closed staple's elbows 158 and crossbar 154. After the forming 
blade descends and closes the staple bevel 152 begins its stripping phase 
and essentially at the same time surfaces 156 will nudge the staple's 
elbows transversely rearward out of the plane of the forming blade. 
Accordingly, the closed staple is cammed by bevel 152, and the staple's 
elbows are cammed by surfaces 156, so that the staple essentially falls 
free of the stapler with no requirement of transverse or upward motion of 
the stapler by the surgeon to effect complete and quick separation of the 
stapler from the closed staple embedded in a patent's tissue. 
During the staple's transport and closing phases, immediately prior to the 
stripping phase, the forming blade's lower guide grooves 160 engage the 
top of the staple's side and, as described above, stabilize the staple 
from tipping or rolling while it is captured between the forming blade and 
anvil and is transported (lowered) and closed. As the closure phase 
proceeds, as seen in FIG. 19, the staple's sides bend from the position 
shown in solid line to the position shown in dotted line, during which 
time the grooves 132 engage, guide and stabilize the staple from rolling 
or tilting. During further closure from the configuration seen in FIG. 19 
to that of FIG. 20, the staple sides leave contact with grooves 132 and 
slide along the inside wall surface of the notch opening 121 of the 
forming blade in FIG. 20 corresponding to wall 156 of opening 162 in FIG. 
23. Subsequently, during the stripping phase in the FIG. 23 embodiment, 
the pair of release surfaces 156 come into engagement with the staple's 
elbows 158 which become quickly released from their frictional engagement 
with side walls 156; with simultaneous stripping of the crossbar, full and 
free release of the closed staple results. 
The anvil is provided with an anti-bowing tang 138 seen in FIGS. 17e and 
17f to prevent the crossarm of the staple from bowing upward when the legs 
are bent downward. The forming blade has a corresponding recess 140 to 
allow space for tang 138 on the forming blade's descent. Bowing of the 
crossarm is undesirable, because such would be a distortion of the 
intended final configuration and result in less effective closure 
security. 
FIG. 17b shows details of the staple cartridge where the mandrel 32 is 
inclined downward about 45.degree. and has a lead edge 33 as a generally 
horizontal lip, so that the lead staple 34A approaches the anvil's support 
lip 20t aligned therewith instead of inclined thereto as seen in FIG. 17b. 
The preferred form of mandrel shown in FIG. 17b tends to avoid the drawing 
down of the number two staple 34A' by the descending forming blade 
immediately after the lead staple is picked up by the anvil. 
In concluding, a number of features will be summarized and/or redescribed 
from a different perspective. Because the stripper cams the crossbar of a 
closed staple off the anvil lip by virtue of continued squeezing of the 
trigger, the closed staple is disengaged from the gun in an essentially 
non-directional manner. More specifically, the surgeon is not required to 
move or urge the staple gun in a particular lateral, vertical or inclined 
direction relative to the engaged tissue to achieve disengagement. It is 
further noteworthy that this stripper is integral with the forming blade, 
so that no additional parts are required to be made or assembled. The 
staple magazine is normally attached to the lower front of the housing by 
an upward movement into the recess provided. As seen in FIG. 17a the line 
of staples is guided between the surfaces 32b and 32c. 
A key feature of this new device is the descending anvil which receives and 
guides the staple downward and then supports and stabilizes it during 
closure. Additional stabilization is provided by the forming blade and the 
housing. A principal benefit of having the staple lowered below the 
housing before closure is that the staple may be essentially fully 
visualized from in front, above and beside the gun before and during 
closure. 
The detent feature illustrated in FIG. 14 allows the trigger to move 
reversibly until detent 15a which is spring biased leftward in the 
direction of arrow 15b, is cammed rightward by cam 15c forcing detent 15a 
to engage projection 15. After this engagement the trigger cannot reverse, 
but can only continue, which helps prevent a double staple feed and 
resultant hang-up. Upon full squeezing of the trigger and full closure and 
release of the staple, release of the trigger leads the resilient detent 
to return by and be cammed forward by cam 15c so that detent 15a and 
projection 15 will not engage. Later, upon repeat of the cycle detent 15a 
is again cammed rearward to engage element 15. 
The stapler described above has been shown as used with a staple which is 
loaded and carried in a partially closed configuration as seen in FIGS. 2, 
6, 3, 4, 17a, 19, et. It is possible in another embodiment, shown in FIGS. 
27-29, to use conventional staples which initially have the typical prior 
art rectangular shape seen in FIG. 26 and in FIG. 29 (stages 1 and 2), 
which is the shape in which these prior art staples are loaded and carried 
by the stapler. After the "initial descent" in this new embodiment, where 
the forming blade makes contact with the staple already upon the anvil, 
the forming blade will continue descent whereby it "partially" closes the 
staple to the shape seen in FIG. 6 and in FIG. 29 (stages 2A and 3). Such 
partial closure may occur before or after the "initial descent" phases, as 
will be explained in further detail later. Upon completion of initial 
descent, the anvil reaches its lower stop, and closure of the staple 
follows generally the procedure set forth with regard to the 
above-described first stapler embodiment. 
In order for the staple to be bent from the open rectangular shape of FIG. 
26 to partial closed state of FIG. 6 or FIG. 29 (stage 2A), the anvil must 
be temporarily restrained from descent while the forming blade descends 
slightly. Such temporary restraint can be achieved in a number of ways, 
two of which are: (1) using anvil and forming blade springs of a specific 
mutual relationship and (2) using a removable, second anvil stop. 
As shown in FIGS. 4a and 17 the anvil 20 has an anvil spring 26, and the 
forming blade 24 has a forming blade spring 28. Initial descent of the 
forming blade until it contacts the top of the staple on the anvil, 
compresses only the softer or weaker forming blade spring 28, while the 
stronger anvil spring 26 continues to urge and maintain the anvil up 
against its upper stop 40a. Next, during the transport phase, the anvil 
spring 26 compresses, allowing the anvil to descend. In the further 
embodiment shown in FIGS. 27-29, the anvil 170 should remain "up" 
momentarily while the forming blade 174 descends slightly, during which 
time the open prior art type rectangular staple 178, also shown in FIG. 
26, is partially closed to a configuration approximating that of FIG. 6. 
The sequence of phases or stages for transport, closure, and release of the 
prior art type staple in the new stapler is shown in FIGS. 28 and 29 which 
correspond closely to FIGS. 4a and 4b, except for differences explained 
below. Stages 1 and 2 are the same, respectively, for delivery of a staple 
to the anvil at its up position and descent of the forming blade to merely 
contact the staple upon the anvil lip. Added structure in this embodiment 
shown in FIGS. 27 and 29 comprises: (a) a movable anvil stop 180 and (b) 
movable staple support pins 182. The anvil stop 180 maintains the anvil at 
its up position even as the forming blade is driven downward slightly, as 
seen in FIGS. 28 and 29 to bend the staple from rectangular to partially 
closed state. The pair of staple support pins 182 below the staple are 
generally aligned with the anvil lip. These pins establish the bend points 
184 where the staple sides bend into the shape indicated at stage 2A, FIG. 
29. 
During Stage 3, further pivoting of the trigger 184 pulls anvil stop 180 
from beneath the anvil arm and pulls pins 182 from beneath the staple, and 
drives the forming blade further downward, thus transporting the staple 
and anvil to the anvil's lower stop 40b. Pins 180 are shown withdrawn in 
FIG. 29, Stage 3. Stages 4 and 5 are essentially the same as in FIGS. 4a 
and 4b. 
In FIG. 27 the anvil stop 180 and pins 182 are pulled by lever arms 
represented by A1 and A2 respectively of trigger 184. The dimensions of 
these arms are determined with respect to lever arm A3 for driving the 
forming blade, such that stop 180 and pins 182 move at the appropriate 
time with respect to the desired descent of the forming blade 174. After 
being moved during Stage 3, stop 180 and pins 182 later return to their 
starting positions by reason of spring resiliency in links 186 and 188 
respectively or by other spring or non-spring means, as the trigger pivots 
back clockwise. 
As an alternative to the added structure of stop 180, the anvil spring 172 
and forming blade spring 176 could be designed with stiffnesses and 
relative stiffnesses (not shown), such that during stage 2A when the anvil 
is to remain at its Up stop position while the forming blade descends 
slightly to partially bend the staple, the anvil is maintained in its Up 
position by the stiffness of the anvil spring. Next, during further 
descent of the forming blade in Stage 3, the force of the forming blade 
overcomes the anvil spring's stiffness. Pins 182 would be used as before. 
Preferred embodiments of the subject invention may comprise a number of 
different combinations of features as will be described below. As seen in 
FIG. 22, a stapler may have the side stripper 156 in addition to the top 
stripper 152 for camming a closed staple off of the anvil. Alternatively, 
a stapler may have the side stripper alone while the mechanism is designed 
for use with staples that are loaded in a partially closed state of FIG. 
46 or staples in a fully open state of FIG. 29. In the latter case each 
staple is first partially closed by the stapler, then lowered, and then 
fully closed and stripped off the anvil. For convenience of terminology in 
both cases, the staple in its initial state may be characterized as "open" 
even though in FIG. 4b it is partially closed in initial stage 1 with the 
legs of the staple extending downward and converging and in FIG. 29 it is 
fully open in stage 1 with the legs extending merely primarily downward. 
It should also be noted that while these two figures refer to specific 
"stages", "1", "2", etc. which are described in detail in prior sections 
above, the forming blade and staple may be deemed, for covenience in 
terminology to be operated through a first period or first stage 
comprising a number of phases during which time staple is bent from "open" 
to "closed" state and moved downward, and through a second period or stage 
during which time the closed staple is stripped off the anvil. 
Accordingly, as defined in claim 4 below, during such first stage, there 
are three sequential phases, namely, a first phase for bending the staple 
from open to partially closed state, a second phase for driving the anvil 
and staple to a second position displaced from the first, and a third 
phase for bending the staple to its fully closed state. 
The stripping stage not only separates or cams a closed staple off the 
anvil, but does so while the stapler remains essentially unmoved except 
for the slight stripper motion. In these embodiments the closed staple is 
cammed in a direction transverse or optionally perpendicular of the 
direction of movement of the forming blade or of the plane of the staple. 
As shown, the staple is driven in a downward direction with respect to the 
stapler in upright orientation; however, the staple when moved may be 
directed in directions other than downward. 
The side stripping element 156 as shown comprises merely an upward 
extending recess in the forming blade's drive surface defining spaced side 
walls joined by a top wall, with a portion of each side wall formed as an 
inclined or bevelled edge relative to the direction of movement of the 
forming blade. The inclination of the bevel of this side stripper and of 
the top stripper is in the range of 20.degree. to 70.degree.. An 
alternative form of side stripper not shown would comprise an element 
separate from the forming blade but coupled to the trigger for operation 
in appropriate timing with the forming blade. 
The various stapler embodiments disclosed herein comprising various 
combinations of the elements and submechanisms described are presumed to 
operate cyclically with a plurality of staples carried by the stapler 
housing; however, each stapler can also operate with a single staple 
combined with the stapler or loaded into an otherwise complete stapler 
apparatus. 
The invention described herein has focused upon certain preferred 
embodiments and features; it is intended, however, that numerous 
variations and equivalent embodiments be considered within the spirit and 
scope of the invention as set forth in the appended claims.