US1834737A

US1834737A - Hair clipper

Info

Publication number: US1834737A
Application number: US459882A
Authority: US
Inventors: Casper L Redfield
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-06-09
Filing date: 1930-06-09
Publication date: 1931-12-01
Anticipated expiration: 1948-12-01

Description

Dec. 1, 1931. Q REDFIELD 1,834,737

HAIR CLIPPER Filed June 9, 1930 Patented Dec. 1, 1931 PATEN oFFicE CASPER Ii. B ennium, or oHIoAeo, rumors HAIR-CLIPPER,

A plication-elem un 9, 1930. Serial No. 459,882.

In ordinary animal shears, the upper blade is driven by an arm; which swings in a fixed plane, and the upper blade restson theface of a lower ,blade,'which face is a plane substantially parallel with the plane in which the arm swings. Under such conditions, it'is a comparatively simple matter to 'keep the two blades in proper contact with each other.

In hair clippers for the use of b-arbers, it is desirable to have the blades set at an angle of about forty-five degrees,'-more or less, to the plane which the-driving arm swings. In a caseof this kind, the face of the lower blade forms one side of apolygon, and the driving arm'act's to move the upper blade in'the arc of a circle.- To make the upper blade move in a straight line when its driver acts to move it in a curve, it'is customary to insert some kind of a spring in the connection between thedriving arm and the upper blade. Such spring is flexed to a greater or-less extent at each strokeof the blade, and such flexing consumes power. It also acts to lift one end of the upper blade'an-d depress the other alternately, and such action operates to produce non-uniform pressureibetween the blades. The main purposeof the present invention is to produce an improved form of connection between the driving arm and the upper blade, when the plane of the blade movement is at a considerable angle to the plane in which the driving arm moves.

In the accompanying drawings Fig. 1 is a plan with the case in section; Fig. 2 is an elevation "with the case in section; Fig. 3 is a section on line 33 of Fig. 2

Fi 4 is a view in the direction 4 of Fig. 2;

Fig 5 is a partial section on line 5-5 of Fig. 2; and

Figs 6 and 7 are exaggerated diagrams to show the mode of operation.

At the rear of the device is a head 10 hav ing a' projection 11 in the form of a channel. A screw 12 serves to hold a metal bar 13 in a fixed position in the ch annel of the projection 11, and at the same time furnishes a pivot for another metal bar 14. Preferably, the bar 13 is somewhat stiffer than the bar 14. A

blade is at an angle ofabout forty-five deface of the lower .blade. Y

screw 15 acts as an adjustable means for pressin the bars apart.

At a point a little to the left of the screw 15, the bars are bent outward from each other and then back to positions substantially parallel with each other. At points 16, the bars are bent toward each other, and then to sub stantial parallelism. In the rectangular space thus formed, is a magnetic core 18 and coil -19 supported on bar 13 and acting uponbar 1 as an armature. a a

When an electric current flows thru the magnet, the bars are attracted toward each other, and when such a current ceases to flow, the bars move from each other by their own resiliency. Because the bar 13 is relatively stiff and carries a considerable load, it moves a less distance than does the bar 14. The device is conveniently operated by an alternating current, and in such operation all movement is confined tothe bars 13 and 14. That is, none of the movement is conveyed to the case 32 which is held in the hand .while the device is being operated.

On the left end of the bar 13 is secured a bracket 20, in the form ofa section of a T- iron, and on the feet oft-his bracket is an ordinary lower blade 21seci1red in the ordinary manner by'screws 22. T 1e face of this grees to the plane in which the bars 13 and 14 move when attracted by the magnet.

On the left end of the bar 14 is another bracket 23 having wings 24, and on the lower faceof this bracket is a narrow rib 25 which lies transversely to the spread of the wings 24. Secured in the wings 24 are pins26 which enter correspondingholes in the upper blade 27.. Then. the bar 14 is reciprocated, the pins 26 serve to drive the upper blade on the 9 V Secured at a suitable place on bar 13 is a sprin'g28, and similarly secured to bar 14 is ,a spring 29. :These springsoverlap each other, as shown in' Fig.3, and a' screw 30,

threaded into spring 28 and acting on spring 29, serves to apply tension to press the bar 14 downward on its pivot 12. This tension operates thru bracket 23 and rib 25 to press the upper blade 27 against the lower blade 21.

Fig. 6 is a diagram in which the movable blade 27 is represented in mid-position, and Fig. 7 shows the same parts at one extreme of movement. The lever or arm 14L of Figs. 6 and 7 represents the bar 14 of Fig. 1, and the pivoting point 15 of thediagram corresponds to a point above the screw 15, of Fig. 1. The face of the rib is the arc of a circle drawn from 15 (Fig. 6) as a center, and'the upper face of the blade 2? is tangent to this are. In other words, there is a rolling contact between the bracket 23 and theblade 27, and pressure for this contactis maintained by the

springs

28 and 29.

In blades of the kind in'common use-with banners,the pitch of the teetln'the distance from one tooth to the next adjacent tooth, commonly about one-sixteenth of an. inch. If the upper blade moves this distance each side of the center line, it is ample for ordinary purposes. In this device, when the upper blade moves in'one direction, the lower blade moves-in the opposite direction, but as the aggregate of both movements from extreme to extreme does not need to be more than one-eighth of an inch, we can proceed on the assumption that the movement is all in the upper blade.

The distance from the rolling contact on the upper blade to the screw 15 would commonly be in the neighborhood of six inches, and the width of the face of the rib 25 may be less than one-fourth of an inch. IVhile this face is the arc of a circle, that are isso short that it does not differ sensibly from a straight line.

In the exaggerated drawing of Fig. 7, there is shown an open space A between the face of the movable blade and the are where it terminates in a' shoulder. The'proporti'ons of short are and long radius in the actual structure are such that this space is always less :than the diameter of a hair which will .0 cut by the device. The object ofthis isto prevent any scrap of hair getting between theroller 25 and the face ofthe'blade 27.

The roller 25 becomesthe rib '25 by cutting into the roller-to produce shoulders-31 (Fig. 7) beyond which the bracket 23 becomes the wings 24- carrying 'pins' 26. The notch thus produced may have a deptlrof about one onehu-ndredth of an inch,- but I make it about twice that amount. The reason for this is to avoid crushing any scrapof hair which might fall into this space while the bracket- 23 rolls on the upper face of blade 27. It will thus be seen that the open spaces under'the rib 25 are always so small that a piece of hair cannot enter, and the spaces under the wings 24 are always so large that a piece of hair will not be caught and crushed. 5

The pins 26 are in the nature-oftee'th to a gear which has its center above the screw 13 and 14.

VVh-at I claim is:

1. In a'hair clipper, a lower blade furnishing anupper plane surface, an upper blade mounted upon said surface, a driving arm moving in a plane at a considerable angle to the plane of f-the lower blade and having wings extending over the upper blade, driving connections carried by-the wings and engaging the upper blade to drive it, and a COIllZflCtyIlb carried by thearm and engaging the upper blade between the driving connections.

2. In a hair clipper, the'combination with a movable blade and a vibrating arm, of a connection secured to said arm, said connectionhaving wings providedwith pins which enter corresponding holes in the blade, and saidconnect-ion having a blade contacting rib between said pins.

3; In a-hair clipper, the combination with a movable blade and a vibratory arm, of a connection secured to said arm, said connection having a centrally disposed rib engaging the upper faceof said blade and having laterally disposed wings raised a material dis tance above the upper face ofsaidblade, and pins securedin said wings and entering corresponding'holes in said blade.

4. Apairof cutting blades, a support for the lower blade, a-segment of a gear having two teeth engaging openings in the upper blade to drive it, said gear'having an are between the-teeth corresponding to the pitch line of the gear and said arc engaging the surface of the upper blade between the openings therein, means for operating the-gear to reciprocate the blade, and tension means operating thru the arc of the gear to press 'the upper bladeagainst the lower blade;

CASPER L. REDFIELD.