Mechanical Scarifier

Abstract

A mechanical scarifier for the controlled abrading of the skin of a patient in allergy testing, for example. The device comprises a guard terminating in an annular end face seatable against a skin surface to be abraded, a rotary blade within the guard and terminating in a scarifying edge adjacent and within the lateral confines of the end face and adapted to abrade the skin surface against which the end face of the guard is seated, means for adjusting the position of the scarifying edge of the blade relative to the end face of the guard in the axial direction, and cam means for rotating the blade about the axis of the end face of the guard in response to axial movement of a housing reciprocable relative to the guard, such rotation of the blade resulting in the desired abrasion of the skin surface.

Description

BACKGROUND OF INVENTION

The present invention relates in general to a mechanical scarifier intended especially for abrading, or otherwise penetrating, the skin of a patient in allergy testing, or the like.

SUMMARY AND OBJECTS OF INVENTION

A primary object of the invention is to provide a mechanical scarifier which will penetrate a skin surface, or the like, predictably and consistently in a controlled manner.

Another primary object is to provide a mechanical scarifier the depth of penetration of which can be adjusted to compensate for different skin characteristics.

More particularly, the invention may be summarized as including, and an important object is to provide a mechanical scarifier which includes: a guard terminating in an annular end face seatable against the surface to be scarified; a rotary blade within the guard and terminating in a scarifying edge adjacent and within the lateral confines of the end face of the guard; and means for rotating the blade about the axis of the end face of the guard to scarify the surface against which such end face is seated.

Another and important object is to provide means for adjusting the position of the scarifying edge of the blade relative to the end face of the guard in the direction of the axis of such end face.

A further object is to provide a housing reciprocable relative to the guard in the direction of the axis mentioned, and cam means for rotating the blade in response to axial movement of the housing relative to the guard in a direction toward the surface to be scarified. A related object is to provide a cam means comprising interengageable cam elements connected to the blade and the housing and, more particularly, a cam connected to the blade and a cam follower carried by the housing.

Still another object is to provide an adjusting means which includes a threaded connection between the blade and the cam and a set screw carried by the cam for locking the blade against rotation relative to the cam.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results which will be evident to those skilled in the skin scarifying art in the light of this disclosure, may be achieved with the exemplary embodiment of the invention illustrated in the accompanying drawing and described in detail hereinafter.

DESCRIPTION OF DRAWING

In the drawing:

FIG. 1 is a side elevational view of a mechanical scarifier which embodies the invention;

FIG. 2 is an enlarged, longitudinal sectional view taken as indicated by the arrowed line 2--2 of FIG. 1; and

FIG. 3 is a perspective view of a rotary blade and cam assembly forming part of the scarifier.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT OF INVENTION

The mechanical scarifier of the invention is designated generally by the numeral 10 in the drawing and includes a guard 12 terminating in an annular end face 14 seatable against a skin surface, not shown, to be scarified. In the construction illustrated, the guard 12 comprises a sleeve 16 having an external annular flange 18 at its rearward end and terminating at its forward end in an external annular flange 20 which defines the annular end face 14.

Reciprocable relative to the guard 12 is a housing 22 comprising a barrel 24 which is externally grooved for gripping purposes. The barrel 24 is provided at its forward end with an internal annular flange 26 which engages the external annular flange 18 on the sleeve 16 to limit rearward movement of the housing 22 relative to the guard 12. The rearward end of the barrel 24 is provided with a tubular closure 28 threaded thereinto.

Disposed within the guard 12 is a rotary blade 30 terminating at its forward end in a scarifying edge 32 adjacent the end face 14 and within the lateral confines thereof. In the particular construction illustrated, the scarifying edge 32 is a straight edge paralleling the end face 14.

The blade 30 is threadedly connected to a shaft 34 which extends rearwardly through and is threadedly connected to a tubular cam 36 within the forward end of the housing 22, the cam being seatable against the annular flange 18 on the sleeve 16 and being separated therefrom by an annular thrust bearing 38. In the particular construction illustrated, the cam 36 is provided in its outer, cylindrical surface with a helical cam groove 40 receiving therein a cam follower 42 carried by the housing 22. The groove 40 extends only about 180.degree. of the circumference of the cylindrical surface. The cam follower 42 is shown simply as a pin pressed into a complementary opening in the barrel 14 and extending into the cam groove 40. Engaging the rearward end of the cam 36 is a thrust washer 44 serving as a seat for one end of a compression coil spring 46, the other end of the spring being seated against the end closure 28.

As will be apparent, if the housing 22 is displaced forwardly, i.e., toward the end face 14 of the guard 12, from the solid line position of FIG. 1 to the broken line position thereof, the cam means constituted by the cam 36 and the cam follower 42 will rotate the blade 30 within the guard 12, the cam being secured against rotation relative to the shaft 34 in a manner to be described hereinafter. Such rotation of the blade 30 causes its edge 32 to scarify a skin surface against which the annular end face 14 is seated, the depth of penetration being determined by the axial position of the blade edge 32 relative to the end face 14. This relative axial position can be adjusted to accommodate skins having different characteristics in a manner which will now be described.

As previously pointed out, the shaft 34 is threadedly connected to the cam 36, the shaft having thereon external threads 48 engaging complementary internal threads in the cam 36. The shaft 34 extends rearwardly through the end closure 28 and has connected to its rearward end a knob 50 provided with an indicium 52 movable relative to depth of penetration indicia 54 on the exposed circumferential periphery of the end closure 28.

As will be apparent, the knob 50 may be rotated in one direction or the other to advance or retract the blade edge 32 axially with reference to the annular end face 14 of the guard 12, thereby increasing or decreasing the depth of penetration, as indicated by the position of the indicium 52 relative to the indicia 54. A radial set screw 56 threaded into the cam 36 is provided with a tip 58 of a suitable plastic, or the like, which engages the external threads 48 on the shaft 34. The set screw 56 is accessible through a radial opening 60 in the barrel 24 when the barrel and the cam 36 are in the relative positions shown. With this construction, the shaft 34 is frictionally held against creeping.

As will be apparent, the present invention thus provides a readily adjustable device which will scarify skins having different characteristics in an accurate and controlled manner, which is an important feature.

As previously noted, the blade 30 is threadedly connected to the shaft 34 so that the blade can be replaced with a sterile one when the scarifier 10 is used on a different patient. The blade 30 may be unscrewed by holding it against rotation with a suitable tool inserted into the guard 12 while rotating the knob 50. A new blade is installed by reversing this procedure, which also restores the shaft 34 to its former position relative to the cam 36.

Although an exemplary embodiment of the invention has been disclosed for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention as defined by the claims appearing hereinafter.

Claims

I claim as my invention:

1. In a mechanical scarifier the combination of:

a. a guard comprising a sleeve having a first external annular flange at its rearward end and terminating at its forward end in a second external annular flange defining an end face seatable against a surface to be scarified;

b. a housing having a hollow interior mounted on said guard to move reciprocally relative thereto, said housing including an internal annular flange at its forward end engageable with said first annular flange on said sleeve to limit rearward movement of said housing relative to said guard, and a rearward end;

c. a cam follower pin connected to said housing and extending into the interior thereof;

d. a shaft positioned within said housing and said guard and being rotatably and axially movable relative to said housing and said guard, said shaft having a forward end, a threaded portion, and a rearward end;

e. a rotary blade removably connected to said forward end of said shaft within said guard and terminating in a scarifying edge adjacent and within the lateral confines of said end face of said guard and adapted to scarify a surface against which said end face of said guard is seated;

f. a cam threadedly connected about said threaded portion of said shaft and mounted for rotation within said housing, said cam having a cylindrical surface with a helical cam groove disposed therein for receiving said cam follower pin, whereby forward movement of said housing and the engagement of said cam follower pin and said helical cam groove will rotate said shaft and blade within said guard;

g. a tubular closure means surrounding the rearward end of said shaft and connected to the rearward end of said housing;

h. an adjustment knob located exteriorly of and at the rearward end of said housing and connected to said rearward end of said shaft for rotating said shaft relative to said cam, said housing, and said guard, whereby such rotation of said knob positions said blade relative to said end face of said guard for determining the depth of penetration by said blade of the surface to be scarified; and

i. means for biasing said housing in a direction rearwardly of said guard whereby said internal annular flange of said housing engages said first annular flange on said guard.

2. A mechanical scarifier as claimed in claim 1 wherein:

said helical groove extends along a portion only of the circumference of said cylindrical surface of said cam.

3. A mechanical scarifier as claimed in claim 1 wherein:

said cam includes an axial opening having a threaded portion for engaging the threaded portion of said shaft, and a lateral opening; and including

a shaft retaining means received within said lateral opening of said cam for engaging the threaded portion of said shaft.

4. A mechanical scarifier as claimed in claim 1 wherein:

said biasing means comprises a spring, said spring positioned around said shaft and between said cam and said tubular closure means.