US2532476A - Deflection equalizing means for shearing combs - Google Patents

Description

Dec. 5, 1950 E. s. BARTLETT 2,532,476

DEFLECTION EQUALIZING MEANS FOR SHEARING vCOMBS Filed Aug. 16, 1948 WCM ZW Patented Dec. 5, 1950 DEFLECTION EQUALIZING MEANS FOR SHEARING COMBS Edwin S. Bartlett, Forest Park, Ill., assigner to Sunbeam Corporation, Chicago, Ill., a corporation of Illinois Application August 16, 1948, Serial No. 44,566

6 Claims."

This invention relates to shearing handpieces and more particularly to means for providing a rigid support for a comb on such a handpiece.

It is customary for shearing handpiece manufacturers to make handpieces in a plurality of sizes and capacities so that a user may have some choice in the width of the comb and cutter of the handpiece. The reason for this is that some users require a handpiece having a relative- 1y Wide comb Vand cutter and other users desire a handpiece having a narrow comb and cutter. Too, in some countries the width of the comb and cutter is limited by statute. From experience it hasv been found that the same driving mechanism may be utilized to drive the cutter mechanism whether the comb and cutter are narrow or relatively wide. In an effort therefore to simplify manufacturing and to effect standardization of parts of handpieces both the narrow combs and the relatively wide combs have been formed with mountinglslots or apertures of substantially the same size spaced apart the same distance. Thus the same mounting screws can be used to secure eithertype of comb to the handpiece. While this standardization of parts has been satisfactory from a manufacturing standpoint it has not been entirely satisfactory from an operators orusers standpoint. Users have found that while a narrow comb, such as a ten-tooth comb, is generally satisfactorily secured tothe handpiece with conventional mounting screws, that a relatively wide comb, such as a thirteen-tooth comb, when mounted by the conventional mounting screws is not satisfactorily secured to the handpiece. For example, as the cutter moves between its lateral positions back and forth across the comb the extreme edge portions of the comb are displaced during the shearing operation. This is believed to be due to the tension force applied to the cutter to hold the latter` in engagement with the comb; that is the tensioning force is so great that it causes the edges of the comb to be deflected away from the cutter, particularly during the shearing operation, when the cutter is in either of its extreme lateral positions. As a consequence, a good shearing action is not ,effected on the edges of the comb of the handpiece. This of course is objectionable from the standpoint of reducing the efficiency of the user of the handpiece.

Accordingly, it is an object of this invention to provide a novel means for securing a comb to thehandpiece which insures that the comb is reinforced along its lateral edges for preventing displacement thereof during a shearing operation.

Another object of the invention is to provide means for securing the comb to the handpiece 2 may be secured to the handpiece in a rigidly supported manner throughout the entire area engaged by the cutter.

VAnother object of the invention is to provide novel means for securing combs of different widths to the handpiece which permits the manufacturerY to standardize mounting hole dimensions on the combs, which is positive in its action, which is simple in construction, and which is relatively inexpensive to manufacture.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which- Figure l is a side elevational view of a shearing handpiece embodying the present invention;

Fig. 2 is a fragmentary bottom view of the handpiece shown in Figure l;

Fig. 3 is a sectional view taken substantially along the line 3-3 of Fig. 2 and showing the parts in a partially assembled position;

Fig. 4 is a sectional line taken substantially along the line 4-4 of Fig. 2 and showing the parts in a partially assembled position;

Fig. 5 is a bottom View of a cutter with a modiiied form of the invention;

Fig. 6 is a sectional View taken Vsubstantially along the line 6-6 of Fig. 5;

Fig. 7 is a sectional view taken substantially along the line 'I-l' of Fig. 5, showing the part in an unassembled position, and v Fig. 8 is a sectional view taken substantially along the line 8-8 of Fig. 5 showing the part in an unassembled position. p

Referring now to the drawings, the invention is shown embodied in a shearing handpiece for shearing sheep and the like. In general, the handpiece includes a handle portion H, a comb I2, a cutter I3, means l!! (of which only a portion is shown) for driving the cutter I3, and tensioning means i6 for adjusting the pressure between the cutter I3 and the comb I2. As shown, the handle portion I! is of tubular construction shaped `to be conveniently grasped by an operator. The comb I2 projects outwardly from the forward end of the handle portion Il as by having its base I'I secured on a shoulder I 8, formed on the underside of the forward end of the handle portion II, as by mounting screws I S. The cutter I3 is mounted on top of the comb I2 and is arranged to be driven back and forth across the comb by the driving means I4. Of the latter, only a yoke 2l drivingly interconnected with the cutter I3 and a pivotally mounted fork 22 are shown. The yoke 2I is formed with downwardly extending projections 23 shaped to be received in spaced recesses (not shown) formed on the upper .surface of the cutter I 3. At its rear end a shank 24 of the yoke 2I is received in a sleeve V25 forming a part of the fork 22. The tensionof. tral portion of the plate 3| is drawn against the ing means I6 includes a tension pin 26 having one end seated in a bearing socket formed in a boss 21, integral with the fork 22, and having its other end, not shown, extending through a sleeve projection 28. The latter is integral with the forward end of the handle portion Il and is inclined rearwardly of the front end of the handle portion. The extreme end (not shown) of the tension pin 26 abuts against a cap 29 threadable on the sleeve projection 28, The pressure between the cutter I3 and the comb I2 may be adjusted by varying the position of the cap 29 relative to the sleeve 28.

One phase of the invention is concerned with means for mounting the comb I2 on the handle portion I I so that the combv is prevented from being displaced relative to the handle portion I I during a shearing operation. For this purpose, in the embodiment of the invention shown in Figs. l-4 a plate 3| is disposed between the heads of the mounting screws I3 and the base I1 of the comb I2. As shown in Figs. 3 and 4 in which the parts are in a partially assembled position, that is the screws I3 are not tightened up, the plate 3I has a concavo-convex cross section in both a transverse and a longitudinal direction. The plate is of substantially the same thickness as the comb I2; has substantially the same overall width as the base i1 of the comb; and extends along the longitudinal axis of the handpiece from the rearward edge of the base I1 to a point adjacent the base of the teeth 32 of the comb I2. The plate is preferably formed of resilient material. With this construction the plate 3I in the partially assembled position, initially engages the comb base I1 at four positions defined by the corners 30 and 30' respectively of the plate. The forward corners 3i) of the plate 3l engage the comb adjacent the base of the comb teeth 32 and adjacent the lateral edges of the base l1. rearward corners 39 of the plate 3I engage the base I1 of the comb I2 adjacent the rear edge of the base and adjacent the lateral edges there- When the screws I9 are tightened the cencomb. As a consequence the marginal portions of the plate and particularly the corner portions thereof are stressed to exert a pressure of greater degree against the comb. This distribution of pressure serves to prevent the comb from being equalize as well as minimize any tendency toward deflection incident to cutter pressure. There is, of course, a small degree Vof deflection in the comb teeth due to their small cross-section, but this is substantially uniform with the present invention.` Thus the plate 3I when in 'its assembled position provides a pressure equalizing support as well as a reinforcement for the cor-nb. The forward edge of the plate 3I may be beveled as shown at V33 to permit the handpiece to be guided readily over the skin of the animal. The mounting holes in the plate 3l for the screws i9 are preferably counterbored so that when the screws I9 arev in a tightened or securing position the heads thereof do not interfere withv the free movement of the handpiece over the skin of an animal.

In the embodiment shown in Figs. 5-8 two generally Y-shaped or forked members 35 and 35 formed from resilient material are utilized as a means to. clamp. a comb 31 to a handpiece 3.4 to

The

prevent relative displacement of the comb with respect to the handpiece during the shearing operation.

The Y-shaped member 35 includes a stem 38 and arm portions 39 and 4 I. The stem 38 as seen in Fig. 8 is formed with an aperture 42 having a rounded bottom for receiving the correspondingly shaped head of a mounting screw 43. At the extreme end of the stem 3B is a projection 44 shaped to engage the lateral portion of the underside of the base 46 of the comb 31. On its arm portions 39 and 4I the Y-shaped member is formed with projections 48 and 49, respectively, shaped to engage spaced positions disposed centrally of the base 4B of the comb 31. The Y- shaped member 35 is of similar construction having a stem portion 5I with a central aperture 52 for receiving a mounting screw 43 and arm portions 53 and 54. rThe stem and arm portions are provided with projections 53, 51 and 58 respecf tively, shaped to engage the underside of the base :36 of the comb 31 in a manner similar to that der scribed for the Y-shaped member 35. As shown in Fig. 5 the arms of the Y-shapcd member y35i overlap the arms of the Y-shaped member 35.

vFor this purpose the Y-shaped member 35 is formed with a recessed portion '59 on its top side which interiits with a similar recessed portion 6i on the underside of the Y-shaped member 35. As shown in Fig. 6, when the screws 43 are in their securing position, the portion of the stems 33 and 5I adjacent the respective mounting holes is forced into engagement with the -bottom of the comb. Because the portions of the Y-shaped members 35 are bowed when the screws 43 are tightened it is to be understood that stresses are set up in the members 35 and 3S to constantly urge the projections into engagement with the comb. Thus, forces for holding the comb 31 in position are applied at lateral positions on the base of the comb and at spaced positions at the central portion of the base of the comb. Thus, this construction provides a comb securing means in which the comb is positively reinforced by the application of equalized pressure at spaced points substantially along the full width of the comb.

It will be observed that in both embodiments pressure is applied along substantially the full width of the comb by means of one or a multiple of clamping plates. This distributes the pressure at pre-determined areas on the clamping plate spaced laterally from the clamping screws I9. This distribution of the pressure has an equalizing effect which serves to provide what might be termed a stabilized support for the clamping plate. This pressure distribution serves to effectively prevent uneven deflection of the comb and particularly deflection oi the end portions of the cutter from the true plane in which its cutting edges are designed to operate. These pressure equalizing and stabilizing eiiects function to promote a ner degree of precision in coaction between the cutting edges of the comb andthe cutter from end to end of the comb, withx the result that the shearing action is improved. Also,4 the tendency toward dulling of the cutting edges due to comb deflections is reduced, with consequent improvement in the life of the comb and cutter.

The embodiments o f the invention shown herein are exceedingly simple in construction. Either construction permits of standardization or parts. Thus, either a narrow ten-tooth comb or a relatively wide thirteen-tooth comb provided.` with standard spacing Vbetween the mounting holes maybe secured to the, handle portion having con,

ventionally spaced mounting screws. As a result of the constructions disclosed herein a relatively wide comb may be secured to the handpiece ll in a rigid manner without requiring a specially designed handpiece.V A

While I have shown two embodiments of my invention it will be understood that I do not wish to be limited thereto since many other modifications may be made and I therefore contemplate by the claims to cover such modications as fall within the true spirit and scope of my invention.

I claim:

1. In a shearing handpiece, the combination of a handle portion, a comb projecting outwardly from the handle portion and having a base portion seated thereon, a cutter movable back and forth across said comb between extreme lateral positions, tensioning means engageable with said cutter for applying a pressure thereto to urge the cutter into engagement with the comb, resilient plate means disposed adjacent the comb and shaped when initially assembled adjacent the comb to engage the latter at a plurality of spaced positions, two of said positions being adjacent opposite lateral edges of said comb, and means for securing the plate means' to the comb and deforming said plate means to a position in which the portions thereof adjacent the securing means are in contiguous relation with the comb, and said plate means is stressed to urge the lateral portions thereof into engagement with the lateral edges of the comb to provide a support for the comb to positively retain the lateral edge portions in a fixed position as the/cutter moves between its lateral positions.

2. In a shearing handpiece, the combination of a handle, a comb projecting axially outwardly from the handle and having a base portion seated on said handle, a blade movable back and forth across said comb between lateral positions, tensioning means engageable with the blade for applying a pressure thereto to force the blade into engagement with the comb, a plate movable between a position in which it has a surface which is generally concave in both a transverse and a longitudinal direction, and a position in which said surface is in contiguous relation with the comb, said plate in the latter position being stressed to have its edge portions urged into engagement with the comb, abutting against said base portion to provide a reinforced support for the comb as the cutter moves between its lateral positions, and means for securing the plate in its last mentioned position.

3. In a shearing handpiece, the combination of a handle, a comb projecting outwardly from the handle and having a base portion seated on said handle, a 4blade movable back and forth across said comb between extreme lateral positions, tensioning means engageable with the blade for applying a pressure thereto to urge the blade into engagement with the comb throughout its path 'of travel, a first forked member having projections on each of its arm portions engageable with the base portion at spaced axial positions disposed centrally thereof and having a projection on its stem portion engageablewith the base portion along one lateral edge thereof, a second forked member having projections on each of its arm portions engageable with the base portion at spaced axial positions disposed centrally thereof and having a projection on its stem portion engageable with the base portion on its other lateral edge, and means for securing thev forked members and the comb to the handle so that the forked members are under stress and the projections are constantly urged into engagement with the comb to provide a reinforcement for the comb for preventing displacement thereof at either lateral edge or an intermediate position during the movement of the cutter between its extreme positions.

4. The combination recited in claim 3 in which the arm portions of the first forked member overlap the arm portions of the second forked member.

5. In a shearing hand piece, the combination of a handle, a comb projecting axially outwardly from the handle and having a base portion seated on said handle, a blade movable back and forth across said comb between extreme lateral positions, tensioning means engageable With the blade for applying a pressure thereto to urge the blade into engagement with the comb throughout its path of travel, a first forked member having its arm portions shaped to engage spaced central positions of the base portion and its stern portion shaped to engage one lateral edge of the base portion, a second forked member having its arm portions shaped to engage spaced central positions of the base portion and having its stem portion shaped to engage the opposite lateral edge of the'base portion, and means extending through each of said forked members for securing the forked members and the comb to the handle, said forked members in their assembled positions providing a reinforcement for the comb for preventing displacement thereof at either lateral edge or an intermediate position during the movement of the cutter between its extreme positions.

6. In a shearing hand-piece having a head equippedwith a comb and a cutter, the comb having a flat body portion and teeth extending forwardly therefrom, means for oscillating the cutter, and tensioning means for applying pressure against the cutter to maintain it in coaction with the comb, the combination of a plate structure adapted to be applied to the under side of the comb body portion, the plate structure having contact portions arranged to engage the under side of the comb body portion at points transversely spaced thereon and adjacent to the outer opposite edges thereof and having additional contact portions for engaging the under side of the comb body portion at points longitudinally spaced thereon, the plate structure intermediate said contact portions being spaced from the under side of the comb body portion when the plate structure is positioned on the comb body portion, and clamping means for applying pressure to said intermediate portion of the plate structure to thereby apply pressure through said Contact portions against the comb body portion at said transversely and longitudinally spaced points.

EDWIN S. BARTLETT.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITEDV STATES PATENTS Name Date Number Cook Jan. 30, 1917

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