US1496296A

US1496296A - Safety razor

Info

Publication number: US1496296A
Application number: US491547A
Authority: US
Inventors: Henry M Chance
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-08-11
Filing date: 1921-08-11
Publication date: 1924-06-03
Anticipated expiration: 1941-06-03

Description

Jam 3 wzw CHANCE SAFETY RAZOR File u 11 192.1 2 Sheets-Sheet 1 YINVENTOR.

WI T NE $555.-

.Be 3, 924. 1,496,296 H. M. CHANCE SAFETY RAZOR Filed Aug. 11. 1921 2 Sheets- Sheet 2 ar; 26/ all 4 12' 12'17' 17' a! w 0U WITNESSES: INVENTOR.

Patented June 3, 1924.

" UNITED STATES PATENT or'rlcn.

HENRY M. CHANCE, OF PHILADELPHIA, PENNSYLVANIA.

SAFETY RAZOR.

Application filed August, 1921. Serial No. 491,547.

My invention relates to means for the application to adjustable safety razors of the Gillette type, of an improvement in safety razors which I have described and claimed in an application for patent Serial No. 486,- 146, filed July 20, 1921, for improvement in safety razors which consists in confining the adjustability of the cutting edge of such razors within a range between two fixed limits, one of which provides little or no exposure of the cutting edges and the other of which provides maximum exposure of the cutting edges consistent with a reasonable degree of safety in use. I

In adjustable safety razors as usually constructed, when the parts are assembled in osition but before the blade is flexed by tig tening the clamp, the cutting edges of the blade project beyond lines tangent to the outside faces of the clamp and guard and are about of an inch above the guard, presenting an exposure of the cutting edges much exceeding that possible for safe use; but when the blade is flexed by progressive tightening of the clamp, the cutting edges move towards the guard until they reach a. position in which they project very slightly beyond aline tangent to the outside faces of the clamp and guard, presenting a very small exposure of. the cutting edges of the blade and a highdegree of safety in use. The

adjustability of the cutting edges of the blade is through a range extending by im-' perceptible graduatio-ns from a. position in which the cutting edge is dangerously exposed to one'in which there is very small, if any, exposure. After clamping tightly, with the cutting edges occupying a position with minimum exposure, a ver slight reduction in the clamping pressure y a-movement of the clamp or cover a few thousandthsof an inch is sufiicient toincrease the exposure of the cutting edges to the maximum-exposure consistent with safety, further reduction in the clamping pressure with but slight movement of the 0 amp or cover increasing this exposure to one inconsistent with safety in use.

Fig. I is an end view of a 201' of the Gillette type showing modifications in the construction of holder and clamp to confine the adjustability of'the exposure of the cuttnig'edges of the blade to within safe limits, the drawing showing the clamp 5 tightened upon the blade 4, but without producing apreciable flexing thereof and showing the lade with about the maximum exposure consistent with safety and adapted to close shavmg. Fig. II shows the same construction illus trated by Fig. I but with the blade tightly clamped and flexed to the limit of possible. fiexure, in which posit-ion the cutting edges have very small or perhaps no exposure, this position being adapted to less close, shaving L than that shown by Fig. I.

Fig. III is a similar end view in which tightening of the clamp or cover 1 will flex the razorblade in a direction opposite to that of the construction illustrated by Figs.

Y I and II. In this Fig. III the clamp, 5, is

shown tightened upon the blade, 4:, but with out sufficient pressure to produce appreciable flexing of the blade. In this position the cutting edges of the blade have little or no exposure and their position with relation to the guards is one adapted to ordinary shaving conditions. In this type of construction, tightening of the clamp, 5, increases the exposure of the cutting edge. Fig. IV is a re production of Fig. III showing the condition when the clamp 5 is tightened to the limit of motion, thus producing the maximum flexing of the blade, corresponding to maximum exposure of its cutting edges consistent with safety in use and "providing a condition adapted to close shaving.

In the drawings like numbers refer to like parts. Th drawings are made on a scale enlarged to about four (4) times the most convenient size for razors of this type.

Fig. I is an end and partly cross-sectional view comprising a holder 1, a guard v2, shown as a bar surmounted by teeth 10 forming a comb and separated from the holder 1, by an open slot 8, but connected to the holder 1 at each end by a wing 9; another guard? is shown as a toothed guard of a adapted to engage with an internal thread 6' cut on the inner wall of the handle T,

The holder 1 is provided with a raised ridge 11 at both sides which acts as a fulcrum on which the blade 4. may be flexed. lhe cover 5 is provided with outer raised ridges 12 for flexing the blade 4: and also a second raised ridge 13,1and has a broad ridge in the form of a contact plane 1a which is not in contact with the blade until flexing of the blade commences, and limits the movement of the clamp 5 to prevent flexing of the blade beyond the predetermined limit. The holder 1, is provided with a similar contact ridge 16, which co-acts with ridge 14 to limit the movement of the clamp 5. It will be understood that the contact ridge 16 may be lowered provided a corresponding change be made in contact ridge 14:, without materially affecting the action of these two contact ridges in limiting the downward movement of the clamp 5 in the desired manner. In this Fig. I the clamp 5 is shown tightened upon the blade 4, thus producing pressure on the blade along the lines of

contact

12 and 13, this pressure being opposed by counter-pressure along the line of contact 11 and by the contact plane 16, the pressure thus applied being suflicient to hold the blade firmly in place in a position adapted to close shaving with the cutting edge slightly projecting beyond the line cd drawn tangent to the clamp 5 and guard 3, but the pressure so applied not being suificient to produce appreciable flexing of the blade 4.

All the drawings show guards of the bar type and an open slot on the left hand side of the holder and toothed guards of the comb type with their upper surfaces shaped to form a channel on the right hand side. It will be understood that the holder may be made symmetrical with guards either of the curved tooth type or of the bar and open slot type on both sides.

In Fig. 11 which is a duplication of Fig. I except that the guard 2 is shown as a simple bar without teeth, the clamp 5 is shown as tightly drawn down upon the blade until the

contact planes

14 and 16 are both in contact with the blade 4. In moving from the position shown in Fig. I. to that shown in Fig. II, the

ridges

12 and 13 of clamp 5, co-acting with ridge l1 and contact plane 16, flex the blade 4 in a reversed curve, thus producing longitudinal corrugations which tend to stiffen the blade longitudinally, and also produce a flexing near the cutting edge a". that lowers the cutting ed es slightly below the line 0-d, thus providin or no exposure, a con ition ada ted to shaving with a high degree of sa et but not to what is ordinarily described as close shaving.

In Fig. III the relative positions of the flexing ridges on the clamp and on the for a very small aeeaee holder are so located that flexing of the blade 4: causes a movement of the cutting edges in an opposite direction to the movement shown by Figs. I and II, progressive tightening of the clamp increasing the exposure of the cutting edges from a position with little or no exposure, to a maximum exposure consistent with safety in use as shown by Fig. IV. In this application of my invention the clamp 5 does not extend over the channel formed by the upper surfaces of the teeth of the guard 3 as shown by Figs. I and II, nor over the'open slot adjacent to

guards

2 and 2 of Figs. I and II.

It will be understood that the ridges on the surfaces of the holder and clamp may be relatively wide, or narrow, or with sharp, flat, or rounded crests; the crests of symmetrical corrugations upon said surfaces may be used as such ridges, and the crest of the ridges on the holder may be located mid way between that of those on the clamp and vice versa. To confine the adjustability of the cutting edges of the blade to exposures of the cutting edges that are within the to make the actual movement of the parts by which flexing of the blade is produced very small, because the maximum permissible change in position of the cutting edges is limited, to a few thousandths or to one or two hundredths of an inch, if a proper deproducing appreciable flexing of the blade,

the application of the pressure and of the counterpressure by which flexing is to be accomplished must be at points which are very close together, but the resistance of the blade to flexing may be increased by supporting the blade, as illustrated by the draw ings at one or more points intermediate those near the ends of the blade, thus dividing the blade. longitudinally into two or more narrow sections each of which will present greater resistance to flexing than the a further movement where the maximum or minimumdegreeiof flexin has been reached.

This provides a means of hmiting the clamping pressureand the flexing to which the blade can be. subjected, and is alsoa safegiiaard against cracking or deforming of the do by. subjecting, it to an excessive stress.

I 'The actual'movement of the cutting edges between the defined limits is so small that it has been necessary to somewhat exaggerate it the drawings to make the construction plain.

It will be evident to those skilled in the art that my invention may be carried out with holders, clamps, guards and clamping means other than those shown by the drawings used toillustrate my invention, and that the method of clamping the blade to secure rigidity and stifl'ness may be applied to both rigid and flexible holders and clamps. I have utilized the right half of each drawing to illustrate the use of guards of the bar type with. or without teeth,'and separated fromgtl-iel holder by an open slot over which :the cutting edge of the razor blade projects, because this form of guard and. the slot behind it have several vadvantages over the comb type of guard with or without an interposed channel between the teeth and the cutting edge. These advantages are, less obstruction in front of and below the cutting edges, greater facility for the escape of lather, cut hairs, etc. from the vicinity of the cutting edges, smooth passage of the bar over the skin, the wiping away of superfluous lather from the hairs immediately before they are intercepted by the cutting edge and ease in cleansing the holder, guards and blade after use.

The term reversed curve in the specification and the claims hereof is used to designate a compound curve in which the direction of curvature changes, as in one in which the centers of curvature are on op osite sidesof the curve, thus in Fig. H the lads between contact points 12, 11 and 13 is flexed in a reversed curve, and the blade between 13, the shoulder of 16 and the shoulder or edge of 14, is flexed in another reversed curve, and the left hand half of the blade is similarly. flexed in two reversed curves, making 4: reversed curves in all. If the ridge 13 be omitted the fiexure of the blade is effected by

rid cs

12, 11, 16 and 14 on each side which wil produce a reversed curve in the blade on each side of its center, or two reversed curves in all. Similarly in Fig. IV the ridges or lines of contact 11', 12', 11', 13,114' and 16, on each side produce two reversed curves in both the right and left hand halves of the blade, or four in all, which are reduced to two in all-if the ridges 13' and 11" be omitted from both sides. Figs. I and II illustrate the use of 3 -ridges on-the' holder and 5 on the clamp, and

Figs. III and IV illustrate the use of 5 ridges on both holder and clamp. It is apparent that the number of reversed curves, or corrugations produced in the blade will depend upon the number of ridges or lines of flexing contact upon the holder and clamp, and these may be increased, or de-.

creased, from those shown by the drawings, theridges dividing the blade into two or more relatively narrow sections which present greater resistance to flexing than the whole blade if flexed as a unit, the blade thus being bent into two or more corrugations, with corresponding increase in its longitudinal stiffness. When the blade used is not one likely to be damaged by the pressure to which it is subjected by tightening of the clamp, the resistance of the blade to further flexing becomes a means for limiting the adjustability of the cutting edge in one direction, and actual contact of the blade and of

ridges

14 and 16 to effect such limitation becomes unnecessary. The resistance of the blade to flexing increases rapidly as the span between the ridges is decreased, the deflection caused by the application of a given pressure varying inversely with the cube of the span between the two ridges upon which the flexing force is applied, thus in Fig. l where the span on the holder l, between ridge 11 and the edge of ridge 16 is about of the width of the razor blade, the force necessary to produce a given deflection in this span is, theoretically, 125 (the cube of 5) times that necessary to produce the same deflection if.

the, blade be flexed as a whole. It is therefore apparent that if the span be small 7 enough a relatively large pressure may be may therefore be applied to the construction of a safety razor, or safety razor blade holder, as a means for holding the cutting edge firmly in a position best adapted to average shaving conditions, without adjustable flexing of the blade.

In this specification and the claims hereof, the wor exposure is used to designate the distance by which the cutting edge of the razor blade projects beyond a line tangent to 1 the outer surface of the clamp an to the outer surface ofthe guard, such tangents being shown on the drawings by broken lines lettered 0-97, and 0'-d.

Applicant does not herein claim limitation .of the range of adjustment in adjustable safety razors to Within safe limits, except in combination Withthe types of construction herein described and shown, as limitation of the range of adjustment to within safe limits has been broadly claimed in another application filed by applicant July 20,1921 for improvement in safety razors, Serial No. 486,146. 7

Having described my invention, I claim:

1. An adjustable safety razor comprising in combination a holder with guards, a transversely flexible two-edged razor blade, a clamp .for clamping said blade to said holder, means for clamping said holder,

' blade and clamp firmly together, a plurality of parallel longitudinal ridges on the surfaces of said clamp, and of said holder adapted to contact with said razor blade and so spaced that said ridges on the holder are not directly opposite to those on the clamp, said ridges projecting from said holder and said clamp a distance suflicient to permit said blade to be flexed without coming into controlling contact with said adapted to contact with such razor blade when such blade is inserted between said holder and clamp and clamping pressure is applied, said ridges being so spaced that those on the said holder are not directly opposite to those on said clamp, said ridges projecting from said holder and said clamp a distance sufiicient to permit said blade to be flexed without coming into controlling contact with said holder and said clamp except along its lines of contact with said ridges, whereby upon application of sufficient clamping pressure said blade will be transversely flexed in a plurality of reversed curves or corrugations and whereby the position of the cutting edges of said blade with reference to their respective guards is changed.

3. A safety razor including a holder hav ing a guard, a handle for said holder, a clamp engaging said holder, a flexible blade between clamp and holder, said clamp en-l gaging ,said blade along four substantial,

lines, means to cause said clamp to approach said holder, whereby said blade is simultaneously flexed and counter-flexed.

In witness whereof I have hereunto set my hand this 10th day of August 1921.

HENRY MS. CHANCE Witnesses:

Gnoncn Manx, GHAs. BUSH.