US2795967A - Clipper construction - Google Patents

Description

June 18, 1957 L. J. WAHL 2,795,967

CLIPPER CONSTRUCTION Filed Dec. 10, 1952 v 2 Shets-Sheet 2 Jmdrzior beofZl/z.

United States Patent CLIPPER CONSTRUCTION Leo J. Wahl, Sterling, 111., assignor to Wahl Clipper Corporation, Sterling, 111., a corporation of Illinois Application December 10, 1952, Serial No. 325,080

4 Claims. (Cl. 74-531) My invention relates to a clipper construction, and more particularly to the construction of that part of a clipper which enables lengthwise adjustment of the stationary clipper blade (comb) with respect to the movable clipper blade (cutter).

The invention constitutes improvements over the particular constructions shown in my prior U. S. Patents Nos. 1,774,046, 1,861,616, 1,895,183, 2,025,137, 2,265,- 880 and Brown U. S. Patent 1,924,676.

In the clippers shown in the aforesaid patents, the stationary clipper blade is mounted in an adjustable manner so that the blade can be advanced or retracted with respect to the movable blade. Because the cutting edge of the stationary blade is tapered, it will be seen that the length of clipper cut can be controlled by advancing or retracting one blade with respect to the other.

In my present construction, as in the case of my prior Patent No. 2,265,880, the stationary clipper blade is mounted on a bracket which is slidable forwardly and backwardly with respect to the body of the clipper. An actuating lever is pivoted to the clipper body, and rotation of this lever through a small arc imparts sliding movement to the bracket.

With this construction, substantial tension must be applied to the lever at all times so that the lever will not rotate and thereby change the adjustment except when consciously actuated by the operator. The tension .preferably should be permanent in character and not subject to change following extended use or careless handling.

One object of the invention, therefore, is to provide a clipper construction wherein the aforesaid actuating lever possesses a desired degree of tension.

Another object is to provide a construction wherein the desired degree of tension is substantially permanent, i. e. it is not lost through extended use.

Still another object of the invention is to provide a construction which is suitable for mass production, and which easily can be assembled without the need for making individual tests to determine if the desired degree of tension is present. In other words, the construction used is such that the manufacturing tolerances usually are well within the various dimensions which cooperate to provide the desired tension.

Still another object is to provide a construction having operating characteristics which are unlikely to be upset or disturbed due to the application of sudden strains, such as might occur when the clipper is accidentally dropped.

Still another object is to provide a construction which is wholly non-adjustable from the standpoint of the user. The parts are assembled at the factory into an optimum relationship which cannot, and need not, be further adiusted by the user.

Another object of the invention is to provide a construction wherein the tension is produced by a plurality of stack of thin, resilient washers, each of which has accurate, predetermined spring characteristics. The washers are substantially thinner than any heretofore used 7, 2,795,967 Patented June 18, 1957 in similar constructions, and they are applied to the construction in flat, undeformed shape.

Prior constructions of this character have used one or more intially bent resilient washers, and these constructions have in general been unsatisfactory because of the difliculty of obtaining accurately predetermined spring characteristics from a bent washer. Further, a bent washer is subject to further deformation when subjected to a sudden strain, and further deformation, of course, upsets the desired tension relationship. Besides improved results, this invention eliminates the need for bending Washers and testing them individually for proper characteristics.

One reason for the success of the present construction resides in the fact that thin springs, or in this case thin washers, maintain proper uniform tension over a larger range of stress than do thicker springs. In addition, if, for example, due to unusual manufacturing inaccuracies, the tension with a stack of four thin washers is too low, the tension can be increased to the proper amount by simply adding a fifth thin washer.

In its broadest aspect the construction of this invention may be used in numerous applications where it is desired to relate two or more relatively movable members in a controlled frictional manner.

Other objects and advantages of the invention will be apparent as the description proceeds, reference being had to the accompanying drawings which illustrate one structural form of the invention. It is to be understood, of course, that in commercial applications of the invention various details might well vary somewhat from those here shown and described.

In the drawings:

Fig. 1 is a side elevational view of the head end of a clipper embodying my invention;

Fig. 2 is a bottom view of the clipper head end with the stationary blade removed for clarity;

Fig. 3 is a sectional view on line 33 of Fig. 2;

Fig. 4 is an exploded view illustrating details of the construction;

Fig. 5 is a top view of the actuating lever which forms part of the invention;

Fig. 6 is a sectional view on line 6--6 of Fig. 5, and

Fig. 7 is a bottom view of the lever.

Referring now to the drawings, my invention is embodied in a clipper having a conventional casing 10. The extreme forward or head end of casing 10 is here called casing portion 11, although it is to be understood that this portion, or a part of it, may comprise an auxiliary member or members which are not strictly part of casing 10 but which are suitably associated with casing 10.

The clipper has a movable blade 12 (Fig. 1) driven by a finger 13 (Fig. 2) from a suitable power source (not shown) within casing 10. Also provided is a stationary blade 15 which is carried by web 16 of a generally U-shaped bracket 17.

Casing portion 11 has a pair of longitudinally spaced grooves 20 and 21 on its bottom side, as best shown in Figs. 2 and 4. U-shaped bracket 17 has the ends of its legs inturned to provide flanges 22 and 23 (Fig. 4) which ride in grooves 20 and 21. Thus bracket 17 is carried by casing portion 11 in lengthwise sliding relation therewith.

One of the legs of bracket 17, namely leg 25, has an opening 26 (Figs. 3 and 4) of substantial size therethrough. In particular, opening 26 has a large dimension in the direction of motion of bracket 17, as shown by the dotted lines which indicate the ends of the opening in Fig. 4.

A bracket actuating lever 27, sometimes called an intermediate member, has an end which on one face bears against bracket leg 25. An opening 28 (Fig. 4) extends through this lever end in general alignment with the aforesaid opening 26, as best shown in Fig. 3.

A bushing or sleeve member 30 (Figs. 3 and 4) extends through the two openings 26 and 28, and one end thereof bears against casing portion 11, as shown in Fig. 3. The opposite end of sleeve member 30 projects somewhat beyond face 31 of lever 27. Sleeve member 30 makes a reasonably tight fit with opening 28 of the lever.

The aforesaid face 31 of lever 27 is provided with at least two spaced upstanding shoulders 33. These shoulders 33, if only two are provided, are oppositely disposed with respect to opening 28, as best shown in Figs. 5 and 6, and they are somewhat spaced from the opening.

A stack of relatively thin resilient washers 35 is disposed in general alignment with sleeve member 30, the central opening of the washers 35 being sufiiciently large to pass the sleeve member. The washer 35 at one end of the stack rests on the shoulders 33, as best shown in Fig. 3, and the washer is thereby spaced above lever face 31 and supported at diametrically opposite points.

A headedmeans such as screw 37 extends through sleeve member 30 into anchored relation with casing portion 11, and screw 37 is tightened so that its head is forced against the other end of sleeve member 30. Thus screw 37 has a locked relation with casing portion 11 and. sleeve member 30.

The length of sleeve member 39 is such that the head of screw 37 when bearing on the other end of sleeve member 30 also bears centrally on the washer 35 at the other end of the washer stack, and in so doing, the originally fiat washers are deformed out of plane, as best shown in Fig. 3. The resilience of the thin washers 35 provides astress which forces the end of lever 27 into a desired frictional relation with the leg 25 of bracket 17.

Because the spring characteristics of the thin resilient washers are uniform over a wide flexing range and are susceptible to accurate predetermination, and because the dimensions of the various parts of the construction can easilybe held to reasonable tolerances, it will be seen that the stress provided by the construction may be accurately predetermined. In assembly, all that is necessary is to fit the parts together as shown in Fig. 3 and then tighten screw 37 until it locks against sleeve member 30. No individual experimenting or testing for proper tensioning is needed with this construction.

A suitable positive connection is provided between bracket 17 and lever 27 so that actuation of the latter imparts a sliding movement to the bracket. In the form of the invention illustrated, bracket 17 carries a pin 49 which rides in a slot 41 in lever 27. The slot 41 extends K in a radial direction with respect to the opening 28 in the lever, and it is cut in the face of lever 27 which bears against leg 25 of the bracket. Slot 41 is best shown in Figs. 5 and 7.

Lever 27 has a substantial length and the portion thereof extending away from the end containing opening 28 is curved to follow the adjacent contour of casing 10, as best shown in Figs. 2 and 4. The free end of lever 27 is provided with a lug 45 which extends in a lateral direction away from casing 10. Lug 45 is thus in position for convenient manipulation in either direction by the thumb of the user when the clipper is held in the manner proper for cutting hair.

From the above description it is thought that the construction and advantages of my invention will be readily apparent to those skilled in the art. Various changes in detail may be made without departing from the spirit or losing the advantages of the invention.

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

1. In a clipper having a casing portion and a bracket carried by said casing portion in sliding relation therewith, said bracket having an opening of substantial size therethrough, the following combination: a lever for actuating said bracket bearing on said bracket and having an opening in general alignment with a portion of said bracket opening, a sleeve member extending through said two openings with one end bearing on said casing portion, at least two spaced upstanding shoulders on said lever adjacent the opening therein, a stack of relatively thin, resilient washers concentric with said sleeve member, the washer at one end of said stack having radially outer por tions bearing on said shoulders, a headed screw passing through said sleeve member and threaded into said casing portion, the head of said screw bearing both on the other end of said sleeve member and the washer at the other end of said stack, said sleeve member having a length whereby said washers are stressed to apply substantial tension between said lever and said bracket, and means connecting said bracket to said lever whereby actuation of the latter imparts sliding movement to said bracket.

2. In combination, a casing portion, a bracket carried by said casing portion in sliding relation therewith, said bracket having an opening of substantial size therethrough, a bracket actuating lever bearing on said bracket and having an opening in general alignment with a portion of said bracket opening, a sleeve member extendingthrough said two openings with one end bearing on said casing portion, a stack of relatively thin, resilient washers on said sleeve member, means on said lever supporting said washer stack in spaced relation to the portion of said lever surrounding said lever opening, said means engaging at least two spaced peripheral portions of said stack, and a headed means passing through said sleeve member and anchored to said casing portion, the head of said headed means bearing both on the other end of said sleeve member and the washer stack, said sleeve member having a length whereby said washers are stressed to apply tension between said lever and said bracket.

3. In combination, a pair of relatively movable members, one of said members bearing on the other member and having an opening therethrough, an elongated sleeve member extending through said opening with one end bearing on said other member and the other end extending beyond the adjacent face of said one member, a stack of thin, resilient washers on said other sleeve member end, means supporting said washer stack in spaced relation to said adjacent face, said supporting means engaging at at least two spaced peripheral portions of said stack, and a headed means passing through said sleeve member and anchored to said other member, the head of said headed means bearing both on the other end of said sleeve member and the washer stack, said sleeve member having a length whereby said washers are stressed to apply tension between the two members.

4. In combination, a pair of relatively movable members, one of said members bearing on the other member and having an opening therethrough, a headed means extending through said opening and anchored to said other member, means cooperating with said headed means to insure predetermined, fixed spacing between the head of said headed means and said other member, a stack of thin, resilient, initially flat washers on said headed means, said stack at one end being engaged at central portions by the head of said headed means, and an intermediate member bearing on said one relatively movable member and on peripheral portions of the other stack end whereby the washers are stressed to apply tension between the two relatively movable members.

References Cited in the file of this patent UNITED STATES PATENTS

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