US3031758A - Casing structure for hair clipper - Google Patents

Description

w. P. WAHL 3,031,758

CASING STRUCTURE FOR HAIR CLIPPER Filed June 24, 1960 FIG 1 INVENTOR. warren 1? waizZ affome 2/5 Unite tates Patent senses Patented May l, was

3,031,758 CASING STRUCTURE FOR HAIR CLIPPER Warren P. Wahl, Sterling, Ill., assignor to Wahl Clipper Corporation, Sterling, IlL, a corporation of Illinois Filed June 24, 1960, Ser. No. 38,542

Claims. (Cl. 30-201) This invention relates to a casing structure for a hair clipper, and more particularly to a casing structure for a hair clipper of the type having a shear blade which is longitudinally adjustable for'cutting hair to selectively desired length.

The shear blade, in a clipper of this type, normally is secured to a channel shaped sliding bracket having inturned end flanges. Heretofore these inturned end flanges were received in guide tracks or grooves integrally formed in the sides of the clipper casing at the forward end. The casing was formed from a plastic or metal material and molded or die cast to shape, but the grooves or guide tracks which were formed in the sides of the casing complicated the molding process and increased the cost of manufacture. In another method of manufacture, the guide tracks were omitted in the molding and were cut into the casing in subsequent machining operations.

Since the adjustable hair clippers often are used by barbers and are subject to hard use, the casings must be formed from a strong rigid material. This created a problem because minor variations in the dimensions of either the grooves, or the bracket end flanges, caused the bracket to rattle if too loose, or to bind if too tight. This often made it hard to smoothly and accurately adjust the shear blade. Consequently the tolerances in the manufacture of the casing, and in particular the formation of the grooves and the bracket flanges had to be small, thus further adding to the cost of manufacture. Also, with use the guide trackswould wear and thus change the original relationship.

It is evident that it would be desirable to provide a strong casing which is constructed so the inwardly extending grooves or guide tracks are easier and less expensive to make, and will notbesubject to expensive wearing, and so larger variations in the dimensions of the end flanges of the sliding bracket will not make it diflicult to smoothly and accurately adjust the shear blade.

Among other things, therefore, one object of this invention is to provide a casing structure for a hair clipper which has all the aforesaid advantageous features.

This and other objects of the invention will become more apparent when read in the light of the accompanying specification and drawing wherein:

FIG. 1 is a side elevational view of a hair. clipper having a casing constructed according to the principles of this invention.

PEG. 2 is a side elevational view of a portion of the opposite side of the clipper shown in FIG. 1.

' FIG. 3 is a side sectional view of a portion of the illustrated clipper.

FIG. 4 is a side elevational exploded view of one side of the casing end portion and the support plate of the clipper.

FIG. 5 is a side elevational exploded view of the casing end portion and the support plate opposite to that shown in FIG. 4.

FIG. 6 is a sectional view taken on line 66 of FIG. 1.

FIG. 7 is a sectional view taken on line 7-7 of FIG. 1.

FIG. 8 is a perspective view of the upper surface of the support plate.

FIG. 9 is a perspective view of the lower surface of the support plate.

Referring now to FIG. 1 of the drawing, the illustrated hair clipper 10 comprises a casing indicated generally by the reference numeral 12. The casing 12 includes casing sections 14 and 16 which are secured together by means such as screws 15.

Casing section 16 has a forward end portion 18 for supporting a shear blade 22 which in turn supports a powered cutting blade 24 see FIGS. 2 and 3. In the illustrated embodiment, the end portion 18 of casing section 16 has slightly offset parallel casing guide surfaces 24 and 26, one on each side thereof, see FIGS. 4, 5 and 6. As best seen in FIG. 3, the forward end of casing section 16 has an opening 27 through which drive finger 28 of motor 30 extends. This drive finger engages and powers cutting blade 20.

A support plate indicated generally by the reference numeral 32 is mounted on casing section 16, see FIGS. 2, 3, 8 and 9. Support plate 32 includes upper and lower portions 31 and 33 and a front wall 35. For reasons to become apparent below support plate 32 is formed of yieldable, low friction material such as molded nylon. In this embodiment, upper portion 31 of the support plate 32 has slightly ofiset parallel support plate guide surfaces 34 and 36 on each side thereof, see FIG. 8.

Support plate 32 is secured to end portion 18 of sec tion 16 by means such as screws 37 which extend through holes 38 in the support plate and into screw receiving holes (not shown) formed in casing guide surface 26 of the casing end portion If, see FIGS. 7 and 8. Support plate 32 preferably has outwardly projecting index pins 49 which are designed to fit into index openings (not shown) formed in surface 26 for properly positioning the support plate thereon.

As best seen in FIG. 6, support plate guide surfaces 34 and 36 are so positioned on support plate 32 that when support plate 32 is mounted on end portion 18, surface 36 will be parallel and adjacent to surface 26 and surface 34 will be parallel and adjacent to surface 24. This arrangement defines inwardly extending guide tracks or grooves 42 and 44 on each side of the casing end portion.

By forming these guide tracks or grooves from separate elements instead of molding or machining them in a single casing section as was done previously, the problem of forming the completed casing section with exact dimensions is greatly simplified, and this results in substantial decrease in manufacturing cost and improved operating characteristics. .I

An opening 46 extends through support plate 32. This opening, as seen in FIGS. 3 and 7, is aligned with opening 27 in the casing end portion 18 when the support plate 32 is mounted thereon. With this arrangement, driving finger 28 extends through opening 46 in the support plate and engages and drives the powered cutting blade, 2%, see FIG. 3. 1

A channel shaped bracket 43 with inturned end flanges 50 and 52 is slidably mounted on the shaver casing 12 with the end flanges 50 and 52 riding in guide grooves 42 and 44,see FIG. 6. Shear blade 22 is rigidly connected to the bracket 48 by means such as screws 54, see FIGS. 2 and 3.

To move the shear blade 22 on the casing end portion, a pivot screw 56 extends through aligned openings 58 and 60 formed in the side of bracket 48 and the side of support plate 32, see FIGS. 7 and 8. A hub 62 with an integrally molded radially extending lever portion 64 is rotatably mounted on the pivot screw 56. This hub is provided with a pin 66 which is parallel to and offset from the axis of screw 56 and the hub 62, see FIG. 7. This pin extends into a recess 68 formed in the side of the bracket 48. With this arrangement, operation of the lever member 64 between the solid and dotted line positions shown in FIG. 1 causes hub 62 to rotate on the pivot screw 56. The resulting movement of pin 66 against the sides of the recess 68 causes the bracket 48 with the attached shear blade 22 to move on the casing end portion 18. In this Way the length to which hair is out can be varied in a manner well known in the art.

Since support plate 32 is formed from yieldable, low friction material such as molded nylon, at least one surface of guide tracks or grooves 42 and 44 will be made from this material. This is important because it permits an increase in the design tolerances of the casing sections and the support plate 32. The reason is that the resilience and low friction characteristics of the material permit rather substantial deviations in the dimensions of the end flanges without adversely affecting the smooth adjustment of the shear blade 22 and the bracket 48 on the casing end portion 18. This increase in the tolerances permits a further substantial reduction in manufacturing cost.

A further advantage aiforded by the resilient yieldable material of support plate 32 is that front wall 35 may be made extremely thin without danger of fracture. This is desirable because it enables driving finger 28 to be positioned farther forward which in turn permits maximum exposure of cutting blade 24} forwardly of the casing. It will be understood that finger 28 must engage blade 20 reasonably close to the blade teeth in order to minimize the tendency of the blade to twist when cutting.

To prevent cut hair from entering the interior of the casing between the upper surface 21 of the powered cutting blade 20 and the lower portion 33 of the support plate, a fin 7t} integrally formed with front wall 35 of support plate 32 extends down from the outer edge of lower portion 33. This fin is pressed into engagement with the upper surface of cutting blade 20. Since the front wall 35 and fin 70 are formed from the aforesaid material, the fin will be resilient enough to bend slightly by its engagement with the surface 21 and will thereby provide a tight hair-proof seal between cutting blade 20 and the support plate 32. At the same time the low friction characteristics of the material do not cause an objectionable power loss due to the frictional engagement between the edge of fin 7t) and the cutting blade.

The invention may be embodied in other forms without departing from the spirit or essential characteristics thereof as set forth in the claims, and the present embodiment is therefore to be considered as illustrative and not restrictive, and it is intended to include all changes which come within the scope and range of the claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a hair clipper, a casing, said casing having an end portion, said end portion including casing guide surfaces on each side thereof, a support plate mounted on said end portion, said support plate including support plate guide surfaces on each side thereof, said support plate guide surfaces respectively adjacent and parallel to said casing guide surfaces and cooperating therewith to define guide tracks on each side of said casing end portion, a channel shaped bracket having inturned end flanges riding in said guide tracks, a shear blade secured to said bracket, and adjusting means mounted on said support plate and connected to said bracket for moving said bracket and shear blade along said tracks whereby said shear blade may be adjustably positioned.

2. The apparatus set forth in claim 1 wherein said support plate is formed from a low friction resilient material whereby minor variations in the fit of said channel shaped bracket will not adversely affect the smooth and accurate adjustment of said bracket. 3. In a hair clipper, a casing, said casing having an end portion, said end portion including casing guide surfaces on each side thereof, a support plate of resilient, low friction material mounted on said end portion, said support plate including support plate guide surfaces on each side thereof, said support plate guide surfaces respectively adjacent and parallel to said casing guide surfaces and cooperating therewith to define guide tracks on each side of said casing end portion, a bracket with flange portions, said bracket mounted on said casing with said flange portions in said guide tracks, and a shear blade secured to said bracket whereby said shear blade can be adjustably positioned wtih respect to said casing by moving said bracket along said guide tracks.

4. In a hair clipper, a casing having an end portion, a support plate of resilient, low friction material mounted on said end portion, said support plate and said end portion each having a guide surface, said guide surfaces having spaced parallel relation and forming a resilient, low friction guide track, a movable bracket having a flange riding in said guide track, the spacing between said guide surfaces no greater than the minimum designed thickness of said flange whereby said flange is slidable in said guide track despite excess thickness in'said flange, and a shear blade secured to said bracket.

5. In a hair clipper, a casing having an end portion, a support plate mounted on said end portion, said support plate and said end portion each having a guide surface, at least one of which is formed from resilient, low friction material, said guide surfaces having spaced parallel relation and forming a resilient, low friction guide track, a movable bracket having a flange riding in said guide track, the spacing between said guide surfaces no greater than the minimum designed thickness of said flange whereby said flange is slidable in said guide track despite excess thickness in said flange, and a shear blade secured to said bracket.

References Cited in the file of this patent UNITED STATES PATENTS 1,745,997 Kocourek et a1. Feb. 4, 1930 1,764,614 Dremel June 17, 1930 2,789,347 Wahl et al Apr. 23, 1957

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