US 3653389 A
Disposable forceps are molded from a suitable sterilizable plastic material and they have a pair of arms joined together at inner ends by a hinge section of reduced cross-section so that outer sections of the arms are disposed substantially parallel to each other when the arms are in their normally inoperative position. When the arms are operated, the outer ends of the teeth engage before or simultaneously with the engagement of the innermost ends of the strengthening ribs. Alignment lugs are provided on an inside surface of each arm which have mateable surfaces to prevent any transverse misalignment between the teeth during engagement therebetween and outer ends of the alignment lugs engage recesses in the inside surfaces of the arms to prevent overstressing and rocking of the teeth.
Description (OCR text may contain errors)
llnited States Patent Shannon [451 Apr. 4, 1972  DISPOSABLE FORCEPS  inventor: Suel Grant Shannon, Harrisburg, Pa.  Assignee: AMP Incorporated, Harrisburg, Pa.  Filed: Jan. 19,- 1970 21 AppL No.: 3,682
52 us. Cl ..12s/3s4, 81/43 Holohan ..128/321 Primary Examiner-Channing L. Pace AttorneyCurtis, Morris and Safford, William J. Keating, Ronald D. Grefe, William l-lintze, Adrian J. La Rue, Frederick W. Rating, Jay L. Seitchik and John P. Vandenburg [5 7] ABSTRACT Disposable forceps are molded from a suitable sterilizable plastic material and they have a pair of arms joined together at inner ends by a hinge section of reduced cross-section so that outer sections of the arms are disposed substantially parallel to each other when the arms are in their normally inoperative position. When the arms are operated, the outer ends of the teeth engage before or simultaneously with the engagement of the innermost ends of the strengthening ribs. Alignment lugs are provided on an inside surface of each arm which have mateable surfaces to prevent any transverse misalignment between the teeth during engagement therebetween and outer ends of the alignment lugs engage recesses in the inside surfaces of the arms to prevent overstressing and rocking of the teeth.
6 Claims, 6 Drawing Figures Patented April 4, 1972 3fi3389 INVENTOR SUEL GRANT SHANNON DISPOSAIBLE FORCEPS This invention relates to forceps and more particularly to improved forceps molded from suitable sterilizable plastic materials.
Plastic forceps are known since they are readily molded from sterilizable plastic material and they are capable of being discarded after use due to the fact that they can be manufactured for low cost.
Conventional forceps are in widespread use in hospitals, clinics and doctorss offices because they can be economically marketed as a presterilized package for a one-time use to remove sutures, handle dressings, hold cotton to swab areas of a patient and other medical uses. The forceps can, of course, be resterilized for reuse if desired.
One drawback of these conventional plastic forceps is that the areas adjacent the hinge point have the same thickness as or a thickness greater than the arms which require relatively high initial actuating forces to be exerted on the arms. Another drawback is that the inner ends of the strengthening ribs engage one another prior to the article-engaging teeth engaging each other and this does not permit effectively engaging an article at the initial engagement of the teeth. A further drawback is that the teeth do not transversely align prior to engagement, which of course, makes it difficult to grasp small items. An additional drawback is the fact that the strengthening ribs have openings therein as part of the aligning means which weakens the arms ofthe forceps.
An object of the present invention is to provide plastic forceps having sections of reduced thickness adjacent the hinged point so that low pinching forces are required on the arms for initial closure.
Another object is the provision of outer ends of article-engaging teeth of the forceps engaging one another prior to or simultaneously with the inner ends of strengthening ribs engaging each other so that an article can be grasped with a minimum of effort.
A further object is to provide aligning lugs to transversely align the article-engaging teeth just prior to the outer ends of the teeth engaging each other.
An additional object is the provision of the aligning lugs assuring that there is proper axial alignment of the article-engaging teeth.
Still a further object is the provision that the aligning lugs define stop means to limit the pressure that the article-engaging teeth exert on each other.
A still further object is to provide aligning lugs of the forceps which will prevent any rocking motion of the article-engaging teeth.
Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an i1- lustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purpose of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.
IN THE DRAWINGS FIG. 1 is a perspective view of a pair of forceps in its originally molded and therefore normally inoperative position;
FIG. 2 is a side elevational view of the forceps of FIG. 1;
FIG. 3 is a view similar to FIG. 2 with the forceps at the initial engagement of the article-engaging teeth when pinching forces are applied to the arms;
FIG. 4 is a view similar to FIG. 3 illustrating the forceps when the article-engaging teeth are fully closed;
FIG. 5 is a view taken along line 5-5 ofFIG. 2; and
FIG. 6 is a view taken along lines 6-6 of FIG. 4.
Turning now to the drawing, forceps F are provided with arms 1 which are connected together at inner ends by a connecting section 2. Each arm 1 is provided with a hinge section 3, an inclined section 4, a straight section 5 and article-engaging teeth 6. Straight sections 5 taper from sections 4 to the outer ends of the arms. Strengthening ribs 7 are provided on the inside surfaces of sections 4 and 5 to strengthen arms 1 and inner and outer alignment lugs 8 and 9 are disposed adjacent article-engaging teeth 6. Strengthening ribs 7 in the area of lugs 8 and 9 have a sinusoidal configuration and this permits the strengthening ribs to extend from hinge sections 3 along sections 4 and 5 with article-engaging teeth 6 being disposed in opposing surfaces of ribs 7.
Lugs 8 and 9 on each arm 1 are axially displaced with respect to each other and also disposed on opposite sides of a medium plane as illustrated in FIG. 5. The alignment lugs 8 and 9 have their inner radiused and angular lead-in surfaces at outer ends thereof which merge into straight guide surfaces to provide the alignment of the teeth, and the lugs engage prior to the teeth 6 engaging to provide the necessary transverse alignment of the teeth as the angular lead-in surfaces of the outer lugs 9 engage each other; axial alignment of the teeth 6 is accomplished during engagement between the outer arcuate ends of the lugs and arcuate recesses 10 in which these outer arcuate ends are disposed.
Lugs 8 and 9 align the teeth in a transverse direction and the lugs and arcuate recesses 10 in which arcuate ends of lugs 8 and 9 are received align the article-engaging teeth in an axial direction. The article-engaging teeth 6 cannot be misaligned as a result of the action of the aligning lugs 8 and 9 under normal gripping pressure. Moreover, arcuate ends of lugs 8 and 9 and arcuate recesses 10 define stop means to limit the pressure teeth 6 exert on each other and also to insure complete engagement therealong. The forward stop means constituting outer radiused ends of lugs 9 and arcuate recesses 10 in which they mate prevent any rocking motion of teeth 6 when teeth 6 are fully engaged along their length as illustrated in FIG. 4
Hinged sections 3 are not as thick as inclined sections 4 and straight sections 5 to provide ease of closure of the forceps and to permit bowing out when pressure at an inner pivot point, which is provided by the inner ends of strengthening ribs 7, reaches a stress condition thereby providing compensation to prevent the hinged sections from breaking.
The tips of article-engaging teeth 6 can engage as illustrated in FIG. 3 prior to or simultaneously with the engagement of the inner ends of strengthening ribs 7 so that no excessive pressure is needed to bring teeth 6 into initial engagement and the transverse and axial alignment of teeth 6 are accomplished by alignment lugs 8 and 9 to assure the positive engagement of an article by article-engaging teeth 6.
The initial engagement of teeth 6, when arms 1 are moved toward one another as illustrated in FIG. 3, is such that sections 5 and all of teeth 6 except the outer ones in engagement are disposed at an angular disposition with respect to each other so that further pressure on sections 5 cause the angular disposition to decrease until all of the teeth are in engagement as illustrated in FIG. 4, and the inner pivot point at the inner ends of strengthening ribs 7 when the inner ends are in engagement causes the hinge sections to begin their bowing out function which allows the proper amount of gripping pressure to be applied to the teeth and this action removes the effect of the hinge sections on the pressure being applied to the teeth. The engagement of the inner ends of the strengthening ribs shortens the working length of the arms.
Ribs 1 1 are disposed along the outer surfaces of straight sections 5 to provide engaging areas for an operator to normally engage the forceps between the thumb and forefinger of an operator so that the ribbed area between lugs 8 and the junctions between sections 4 and 5 define grasping areas for normally grasping the forceps to operate same.
The angular configuration of inclined sections 4 is such that one would not normally handle the forceps here to operate the forceps but would normally handle the forceps along the ribbed areas of sections 5 which represents the optimum area for operating the forceps. The ribbed area, of course, facilitates handling of the forceps. The pivot point at the innermost ends of strengthening ribs 7 is formed when these innermost ends are moved into engagement prior to or simultaneously with the engagement of the article-engaging teeth 6 to limit the degree of pivot and to provide a point to permit the teeth to mesh completely as pressure is being applied to the arms. The innermost ends of ribs 7 may be provided with projections to assure that these come together at the same time the outermost teeth engage. The forceps are incapable of being broken by normal finger pressure.
The forceps are molded in accordance with normal molding techniques from a suitable plastic material that can be sterilized such as, for example, glass-filled nylon, and the forceps is molded as illustrated in FIGS. 1 and 2 with the straight sections and article-engaging teeth being disposed substantially parallel with respect to each other which is a normally inoperative position and the forceps are now ready to be operated.
It will, therefore, be appreciated that the afore-mentioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiment of the invention, which is shown and described herein, is intended as merely illustrative and not as restrictive of the invention.
The invention is claimed in accordance with the following:
1. In a forceps having a pair of elongated arms projecting longitudinally from a unitary connecting section, with tips adjacent to the free ends of said arms being engageable upon pivotal action of said arms toward each other, the combination comprising:
a pair of diverging portions of said arms projecting longitudinally from said connecting section,
a pair of elongated straight sections unitary with and projecting longitudinally from said corresponding diverging portions, each of said diverging portions including a first flexible hinge section of relatively thin cross-section immediately adjacent to the connecting section, each ofsaid diverging portions further including a second relatively thick section unitary with and immediately adjacent to a corresponding flexible hinge section, said elongated arms being provided with corresponding elongated strengthening ribs, each of said ribs projecting laterally from and unitary with said relatively thick section and said elongated straight section of a corresponding arm, each of said ribs having a first end terminating at said relatively thin hinge section of a corresponding arm to prevent strengthening of said hinge section, each of said ribs having a second end projecting longitudinally beyond a free end of a corresponding arm to define one of said tips, and said tips of said ribs being provided with teeth, and said tips of said ribs being provided with teeth, which teeth are interengageable upon flexing of said hinge sections to allow pivotal action of said arms toward each other, said second ends of said ribs extending longitudinally beyond the free ends ofsaid arms and being tapered to define said projecting tips.
2. The structure as recited in claim 1, wherein, said first end portions of said ribs are initially in opposed spaced relationship and are engageable with said hinge section being retained in bowed and generally diverging relationship upon pivotal action of said arms toward each other.
3. The structure as recited in claim 1, wherein, each of said ribs is continuous from its first end to its second end thereof, said ribs having mutually opposed sinusoidal sections with a pair of lugs protruding from each sinusoidal section and spaced longitudinally along a corresponding rib, and said lugs of one rib overlap the corresponding lugs of the other rib upon pivotal action of said arms toward each other.
4. The structure as recited in claim 3, wherein said sinusoidal section of each rib is located along said straight section of a corresponding arm, said straight section is provided with a pair of generally arcuate recesses on opposite sides of said rib at the sinusoidal sections thereof, and each pair oflugs is provided with a generally arcuate end portion for mating registration within corresponding arcuate recesses to prevent any rocking motion of said interengaged teeth and to define stop means for limiting the pressure between said interengaged teeth.
5. The structure as recited in claim 1, wherein, said first ends of said ribs are engageable to define a secondary pivot point for said arms, and thereby shorten the effective working pivotal length of said amis,
6. The structure as recited in claim 1, wherein, said first end portions of said ribs are initially in opposed spaced relationship and are engageable with said hinge section being retained in bowed and generally diverging relationship upon pivotal action of said arms toward each other, and wherein, said first ends of said ribs are engageable to define a secondary pivot point for said arms, and thereby shorten the effective working pivotal length of said arms.