Hemostat

Abstract

An inexpensive, easily manufactured surgical hemostat comprising a pair of intersecting arms pivotally mounted on a common axis each arm having a plastic coating over its entire length, whereby the functional elements of the hemostat, i.e., the jaws, finger loops and latching means are formed from the plastic and the core provides the requisite strength and resiliency for the arms of the surgical hemostat.

Description

BACKGROUND OF THE INVENTION

This invention relates to method of manufacturing surgical hemostats and the hemostats produced thereby.

Surgical hemostats are very critical instruments which must have strength and reliability. Mainly these requirements have to be achieved by manufacture of the hemostats from polished stainless steel. These are superior instruments usually requiring a great deal of hand finishing, with the consequent high cost, however, because such instruments are used and reused for years, this high initial cost was not considered a detriment. Now a new factor has entered this picture, which has made the use of these expensive devises unattractive. This is the extremely high labor cost now encountered in medical facilities. Hence the added expense of cleaning and sterilizing surgical hemostats is now a significant factor to consider, and even worse in labor short facilities, the availability factor of the cleaned and sterilized materials may be unreliable.

In many procedures, such as male circumcisions, a circumcision clamp suture, clamps and hemostats are maintained together as unit, so that the physician can open one package and have immediately at hand every item needed for the procedure. When prior art hemostats are employed in these packages, not only has there been the cost of labor, but the expensive device is tied up in a storage situation.

It is an object of the present invention to provide an alternative to the prior art hemostats which can be manufactured easily from less expensive material and with less costly labor. It is another object of the present invention to provide hemostats high strength and reliability. It is a further object to provide hemostats that can be combined in an economical preprepared surgical package.

SUMMARY OF THE INVENTION

Briefly stated the method of the present invention for making one arm of an intersecting pair of arms comprises forming a metal core having a handle portion, a jaw portion and a box portion intermediate said handle portion and said jaw portion, tempering said metal core, mounting said tempered metal core in an injection mold, injecting a polymeric material into said mold, coating said metal core with polymeric material and forming gripping surfaces on said jaw portion and a finger loop and latching means on said handle portion. The arm so formed is attached at the box with another similarly formed arm to form a pair of intersecting arms by pivot means interconnecting said arms for swinging motion about a common axis.

The surgical hemostat comprises a pair of intersecting arms and pivot means interconnecting said arms for rotating motion about a common axis said arms each comprising a tempered metal core having a handle portion, a jaw portion, and a box portion intermediate said handle and jaw portions, entirely embedded in a plastic shell comprising a finger loop juxtaposed to said handle portion, a gripping surface juxtaposed to said jaw portion, a latching means interior of said handle portion, said gripping surfaces being operably opposed and said latching means being operably engageable when said handle portions are rotated toward each other for holding said handle portions in a fixed position and operably engaging said gripping surfaces.

DRAWINGS

FIG. 1 is side elevation of a surgical hemostat.

FIG. 2 is a partial cross sectional view along line 2--2 of FIG. 1.

FIG. 3 is a cross section of the hemostat along line 3--3 of FIG. 2.

FIG. 4 is a cross section of the hemostat along line 4--4 of FIG. 2.

FIG. 5 is a cross section of the hemostat along line 5--5 of FIG. 2.

FIG. 6 is a view of the latch means 8a and 8b as shown in FIG. 2 rotated 90.degree..

DETAIL DESCRIPTION OF THE INVENTION

The manner of producing the surgical hemostate is very critical to achieving the product having the necessary attributes to qualify for use as such. Hence the process will now be described in more detail. The process used herein is generally described as insert molding and distinguishable from a process where a coating of a plastic is applied over a blank. In a coating process the only configuration is that of the blank, whereas in insert molding the configuration of the molded article is that imparted by the mold. Hence insert molding is a variant of injection molding wherein the polymer is forced into the mold under pressure. Some attempts have been made to produce hermostats by injection molding, however, the products usually do not have the requiste degree of stiffness necessary when the hemostat is clamped, and these devices have had very limited acceptance by the medical profession.

The deficiencies of prior injection molded hemostats are overcome by inserting a particular type of member into the mold and injecting the polymer around the inserted member. The insert is a single piece of material having the general configuration of one side or portion of the hemostat along the long axis. That is, the insert is a substatially straight member which is formed out of tempered steel. For example, 410-412 guage stainless steel wire is stamped in the general configuration of a handle, box and jaw. It may be necessary to stamp only the box in some of the hemostates. A hole may be stamped in the box at this time. The stainless steel wire is then heat tempered at 1,800.degree. - 2,000.degree.F and air cooled.

The insert is then mounted in the mold, being positioned therein by one or two pins. Precautions are taken to prevent extrudate from filing the hole in the box, said hole if present is a convenient point of mounting the insert. The mold contains the configuration for jaws as well as finger loop and latch element. Thus various jaw configurations may be applied to a standard insert blank. The finger loop and latch element are not reinforced and there is no insert portion corresponding thereto. The reinforcement is along the length of the handle, through the box and in the jaw.

The polymer used to mold the hemostate can be any present extrudable polymers, such as, polypropylene, polybutene, polyamides, polyamines, polymethacrylates and polymethylmethacrylates or any of the other polymeric materials which are extrucdable. Included are material such as epoxy polymers which are cross linked after setting. A desirable feature or property for any polymeric material employed is high temperature resistance to deformation. This conveniently allow the instruments to be heat sterilized.

The hemostat produced in the process described above is shown in FIGS. 1-6. In FIG. 1 the assembled hemostate is shown from the side with the metal core or insert 1 in dotted lines. The jaw portion 7 and handle portion 5 are shown to be in substantially the same plane with the box portion 6 being stamped or bent out of line so that the two polymer covered halves or arms of the hemostat will aline and put the handle and jaw portions of each arm in about the same plane. The two arms are in substantially the same plane to avoid the tendency of the instrument to rotate about its long axis. The tendency to rotate is a result of the unequal pressure that is applied by hand and the torque created thereby.

Referring now to FIG. 2 one arm of the hemostat is shown in cross section along line 2--2 of FIG. 1. Each arm is composed of metal core 1 which, although it is preferably one piece, consist of three decernable elements the handle portion 5, the box portion 6 and the jaw portion 7.

Over the entire core is a cover or shell 10 of a polymeric material, except at the point 4 wherein a pin or other pivot is placed through the two arms joining them at the box. The hole 3 is a mold mount used to hold the core in place in the mold. The shell 10 also is formed into finger loops 2, latching means 8a and 8b and gripping serrations 9 in the jaw portion 7.

The latching means 8a and 8b are shown in the closed or latched together, hence causing the jaws 7 to grip tightly together. Referring to FIG. 6 the means of operation of the latching means can be readily seen. The latching means is comprised of two members 8a and 8b, one each attached on the interior surface of one arm of the hemostat. The members 8a and 8b are somewhat flexible, hence although they are depicted in FIG. 6 as being directly opposed when the two arms of the hemostat are pulled together, the beveled surfaces 11a and 11b cause the two arms to deform and allows then to upon each other thereby engaging the teeth 12 and locking the hemostat in a desired position. The teeth 12 are released by using the fingers to distort the arms temporarily thereby disengaging the teeth and allowing the hemostat to be opened.

FIG. 3 shows a cross section of the hemostat in the jaw portion 7. The two opposed core jaws 7 are shown to have a broadened surface backing up the molded serrations 9. The enlarged portion of the jaw core 7 can be obtained by stamping or twisting the blank from which the core is made. In FIGS. 3 and 4 the polymer covering 10 can be seen to be very thin in some areas. This is not particularly detrimental since the covering is not the element providing the strength and need be only of sufficient thickness to provide a complete sterilizable covering on the surface of the hemostat.

FIGS. 4 and 5 show cross sectional views of the box and arm portions of the hemostat respectively.

The configuration of the hemostat can be varied from that shown to resemble the conventional configurations employed in the act now.

Claims

The invention claimed is:

1. A surgical hemostat comprising a pair of intersecting arms and a pivot means interconnecting said arms for rotating motion about a common axis, said arms each comprising a tempered stamped wire metal core having a handle portion, a jaw portion and a box portion intermediate said handle and jaw portions, said arms each being individually permanently embedded in a plastic shell comprising a finger loop juxtaposed to said handle portion, a gripping surface juxtaposed to said jaw portion, and a latching means on said handle portion on the opposite side of said handle from said finger loop and in substantially the same plane therewith, said gripping surfaces on each jaw being operably opposed and said latching means being operable engagable when said handle portions are rotated toward each other for holding said handle portions in a fixed position, and operably engaging said gripping surfaces.

2. The surgical hemostat according to claim 1 wherein said metal core comprises a substantially straight stainless steel wire.

3. The surgical hemostat according to claim 2 wherein said box has a hole therein.

4. The surgical hemostat according to claim 3 wherein said cores lie in substantially the same plane except for said box portion.

5. The surgical hemostat according to claim 3 wherein said plastic is a themoplastic.