US1496295A - Safety razor - Google Patents

Description

H. M. CHANCE SAFETY RAZOR Filed July 20 1921 m T m V N 1 h, ha. 0AM

Patented June 3, 1924.

. U TED STATES PATENT. oFFiCE- nnnmr M. CHANCE, or PHILAJ'JELPEIA, rnnnsnvhma SAFETY RAZOR.

. Application filed July 20,

have invented certain new and useful Improvements in Safety Razors, whereof the following is a specification. a My invention relates primarily to safety razors that use a two-edged blade, that is a blade with two. cutting edges, such, forexample, as the Gillette razor blade, but its; application is not limited to that particular kind of two-edged blade, nor to the use of holders commonly used with such blades,as it is a plicable also to holders that donot curve or iiex the blade, to two-edged blades that are not of the flexible type and to single-edged blades. p

In flexible blade razors, flexing of the blade is used as a meansfor adjusting the position of the cutting edges of the blade and their angular direction, thus enabling the ,user, within certain limits, to adjust the cutting, edges to shave closely or not as may be desired. Owing to slight diflerences in such blades, all blades do, not flex or bend uniformly or symmetrically, and change in flexure of the. blade may cause the cutting edge to warp or curve in a simple or compound curve, insteadof bending to form the straight (or uniformly curved) line required for safe and efficient use. In addition to this diflicultyinherent to adjustment by flexing, ignorance, lack of skill or inattent'ion on-the part of the user in adjusting the blade for use, frequently are the cause of scraping of. the epidermis or actual cutting ofthe skin. For these reasons adjustments that do not depend for safety upon the exercise of in.- telligence, skill or .care on the part of the user are preferable to those that require skill insetting every time the razor is used.

Myinvention is intended to overcome, or

i to minimize the element of uncertainty and danger of damage in the use of safety razors. of the so-called'adjustable type and which depend upon fiexing the blade in varying degree to change the position of the cutting edge with reference to the guard. To justify the name. asafcty razor should be a prac tirally safe instrument'when assembled for use in any possible position of the cutting edge and the guard.- To effect this, it be struction of the 1921. Serial No. 486,148.

comes necessary to confine the range of the adjustment available to the user, within preciseand definite limits.

I attain this object by flexing the-blade or by flexing a portion of the holder, or the guard,jin such manner as to change the relative position. of the guard with reference to the cutting edge adjacent thereto, the degree of flexing, whether of the holder or of the blade, being positively limited by the conparts that co-act to produce the flexing. f r V Fig. I is an end and partly crosssectional View, showingmy inventionapplied tothe construction of a raz'orin which theholder is flexible andshowing the cutting edge of the blade and guard in a position insuring the greatest safety, and Fig. 11 is another view of the samevdevice showing the holder flexed and-the cutting edge of'the blade and guard in a position'adapted for close shaving. These two posit-ions being the extreme positions possible, any intermediate adjustment causes the cutting edge of the blade and of the blade with the holder and clamp in approximately the position shown, which gives little, if any, exposure of the cutting edge of the blade, and Fig. IV shows the same device with the relative positions of cuttingedgeand guard changed to permit of use for close shaving, by flexingthe blade to the greatest degree of flexingpossible, thus providing for practically the same range in relative positions ofthe cutting edges and guard as that obtained by the device illustrated by Figs. I'andII,

In Figs. I and II, 1 is a flexible holder, 2, 3 are guards, showndiagrammatically as of the comb or toothed type, 4 isa doubleedged razor blade, 5 a clamp, 6 ascrew attached to clamp 5for clamping the parts together, and 7 1s a handlewith an internal .thread fittin the screw'6-. 1 v

In Figs. I I and IV, 1' is a holder, 2', 3 are guards, 4' is a double-edge flexible razor blade, is a clamp, 6' is a screw attached thereto and 7 is a handle threaded toengage with the screw 6.

The drawings are made on a large scale and show the exposure-of the cutting edge, the clearances between the cutting edge and the guard, and the differences in angular direction of the cutting edge "more or less exaggerated in order to show clearly the vprinciple of construction. In most cases! the adjustment to be made betweenordinary at a creasing the distance that the cutting edge I and close shaving conditions is very small, amounting to but a few hundredths or thousandths of an inch. If the dimension :0 or y be relatively large, then 10 or 2 may be so small that the cutting edge to does not reach or intersect the line c-d, and yet may provide conditions that permit of satisfactory and even relatively close shaving if the razor be firmly pressed against the skin, be cause, owingto the distance being large,

the skin will curve inwards between the guard and the cutting edge a, thus bringmg the latter in contact with the skin. Un-

der these conditions the angles'bra-d, and b'a-d" will be much smaller than .those shown diagrammatically by the drawings. It will of course be understood that in this,

as in all safety razors, .the safety of the,

razor is less when the razor is designed or adjusted for close shaving than when the adjustment is for less close shaving.

In Fig. IV the cutting edge of the blade is shown projecting quite an appreciable distance beyond the line c d', a con dition that involves some element of danger unless care be exercised by the user, and this exaggerated condition shown may be avoid-' ed in practice, either by flattening the curve of the holder, lengthening the guards or de projects beyond the holder 1'.

In carrying out my invention, I do not limit myself to the comb or toothed type of guards shown by the drawings. It is ObVl".

ous that any suitable type of guard may be used, with or without teeth. If a bar be used as a guard, it may be separated from the cutting edge and from the adjacent part of the holder by an open slot. Such bar guards may be made with a smooth surface or may, be provided with corrugations, projections or teeth. The advantage of thebar-type of guard is that it does not clog, is easily cleaned and it facilitates the use of an an lar sliding movement of the razor by which the cutting edge is drawn diagonally across the hairs instead of squarely across them. In using atwo-edged blade, it may often be desirable to use different types of guards for the two cutting edges. It will be understood that the resiliency of the holder, when a flexible holder is used, or of the blade, when a flexible blade is used, keeps a stress u on the screw 6 which tends to hold or loc it in macaw place, thus keeping the razor firmly clamped in the position in which it is set.

In the type of construction shown by Figs." I and II, the .end, 10, of the holder adjacent to the guard, is in contact'with the blade close to its cutting edge, firmly pressing. the blade against the clamp 5, thus keeping the cutting edge from warping longi tudinally and holding it rigidly in place.

tion to each other such that-the cutting edge has its minimum degree of exposure and its maximum degree of protection by the guard, and is not therefore in the position best adapted for close shaving;

. 2. If the clamp be further tightened, the position of the cutting edge and guard with relation to each other is changed in such manner as to increase the exposure of the cutting edge, and decrease the degree of pm:

I tection of the. guard, thus bringing the cutting edge. into a position better adapted for close shaving;

3. Ifith'e tightening of the clamp be carried to the limit imposed by the relations and dimensions of the clamp and holder, the position of the cutting edge and guard with relation to each other is changed in such manner as to further increase the exposure of the cutting edge, and further decrease the ,protect'ion- ,of the guard, thus bringing the cutting edge into a position adapted for close shaving, without, however, causing sufficient exposure of the cutting edge to destroy the element of safetyin use;

4. As further movement of the parts is impossible, it-is evident that the desired adjustments are-effected between two definitely fixed limits, and that the razor is safe irrespectiveof the way in which it may be adjusted by'the user. i

5. After tightening the clamp to the'limit,

that is, toithe close shaving position, any

change made by slackening the stress upon the clamp, decreases the exposure of the'cutting edge, increases the protection of the guard and increases the factor of safety in use.

My invention thus provides a new method for adjusting safety razors in which increase in the clamping pressure decreases the factor of safety upto the permissible exposure of mg pressure increases the factor of safety so that, as shown by the drawings, Figs. I

and III, the parts may be so proportioned Ill see

the cutting edge and decrease in the clampes es as to give no exposure of the cutting edge when the razor blade is in its initial position as clamped for use, and maximum exposure consistent with safety, when the clamp is tightened to the limit fixed by the construction and proportions of the parts.

I do not limit myself to the particular applications of my improvement which I have described in detail, nor to the use'of the two types of appliances illustrated by the drawings, as my lnvention, as already indicated, may be carried out by other means and may be applied to other types of holders and clamps than those shown and described. While I prefer the types in which progressive tightening of the clamp changes the adjustment from the least to the greatest exposure of the cutting edges consistent with safety in use, my improvement may be applied to types of holders and clamps pronate the distance by which the cutting edge of the blade projects beyond a line drawn tangent to the outer surface of the clamp and also tangent to the outer surface of the guard, as indicated by the broken line e-d of Fig. I and ca5 of Fig. IV.

Having described my invention, 1 claim,

1. A safety razor including a holder hav ing a guard, a handle therefor, a clamp engaging said holder, a blade between clamp and holder, one of said elements being flexible, means to flex said element, said blade, at the initial position of flexure of the flexible element, having surface contact with said clamp, and a line contact with said holder.

2. A safety razor including a holder having a guard, a handle therefor, a clam engaging said holder, a blade between 0 amp and holder, ble, means to flex said element, said blade at the initial position of flexure of the flexi ble element, having surface contact with said clamp, and two line contact with said holder. i

3. A safety razor including a holder having a guard, a handle therefor, a clamp engaging said holder, a blade between clam and holder, one of said elements being flex1 ble, means to flex said element, said blade at the initial position of flexure of the fiexi ble element, having surface contact with said clamp, and a line contact with said holder, said line contact being between the longi tudinal center of said holder and the guard said surface contact including a portion of the blades upper surface.

In witness whereof I have hereunto placed my hand this 16th day of July, 1921.

HENRY MI. CHANGE. Witnesses CHAS. BUSH, CARL K. SOHULZE.

one of said elements being flexi-

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