US2641091A - Apparatus for sharpening razor blades and other blades - Google Patents

Description

June 9, 1953 w. s. BUcKLlN 2,641,091

APPARATUS FOR SHARPENING RAZOR BLADES, AND OTHER BLADES Filed July 50, 1948 5 Shees-Sheet 1 la a8 El a3' e8 30 a6 o als? ,30

June 9, 1953 w. s. BUcKLlN l 2,641,091

APPARATUSAF OR SHARPENING RAZOR BLADES, AND OTHER BLADES- Filed July 30. 1948 3 Sheets-.Sheet 2 vJune 9, 1953 w. s. BUcKLlN 2,641,091

APPARATUS FOR SHARPENING RAZOR BLADES, AND OTHER BLADES Filed July so, 1948 3 Sheets-Sheet 3 Patented June 9, 1953 APPARATUS FOB SHARPENING RAZOR BLADES AND OTHER BLADES Walter S. Bucklin, Brookline, Mass.

Application July 30, 1948, Serial No. 41,546

18 Claims.

This invention relates to improvements in apparatus for sharpening razor blades and other blades.

More particularly it provides mechanism and means for restoring keenness to razor blades of those modern types which are separable from the razor handle. Such blades are small thin plates of steel, having either a single cutting edge or two opposite cutting edges. For its fastening of the blade to the razor handle each blade may have stud holes, or have special shape. or may have a ridge, or, devoid of all such devices, may be a mere small piece of steel, a quarter inch or so wide and an inch or two long, with a single cutting edge.

It is among the objects of the invention to provide for perfection of sharpening; for speed of action; for safety of the user in his handling of such small sharp pieces of steel; and for safety of the apparatus, by preventing the strops from becoming cut by the blade. Also it is desired that no skill be required of the user, for his handling of the blade relative to a strop. Hence the invention provides so that the operating action required of the user is a mere thrusting back and forth. 'I'herefore the Sharpener is also one that can be operated by mechanical power, and so it can be used for the finishing of the original sharpening of a blade; and can be arranged for sharpening other blades, mechanically, or privately by hand.

Also it is among the objects that the apparatus shall be capable of manufacture at low cost, so as to be available for general popular distribution for private use.

Many proposals have been made for razor Sharpeners; but none has attained this combination of merits; and, so far as I am aware, no device at all has been made that would enable a private user to conserve his blades of the very small type above mentioned. Hitherto each of these has had to be discarded When its edge has become turned.

Modern blades are very thin, in some cases approximating the thickness of paper, and the very keen cutting edge easily becomes bent to one side. The Sharpener of the present invention applies two strops to each cutting edge. The term strop is used herein to indicate any of those smoothing, honing or otherwise abrading substances which are useful for sharpening a blade by rubbing its taper to a cutting edge. These two strops pinch the blade between themselves, and simultaneously rub down its taper and oir its edge with pressure which restores the straightness of any portions that have been bent, and freshens the edge by abrading the taper, without bending the extreme edge toward either side.

As suitably selected leather is extensively familiar for strapping, the Word leather is used herein to typify all stropping substances and their substitutes, except where the context indicates otherwise. However, I have conceived a very superior leather substitute, which can be used for strops of any kind. In this a flexible synthetic sheet-form composition, of any of the suitable varieties of plastic, has rouge or other very finely divided abrasive material disseminated throughout its mass. The surface of this may gradually wear away, with repeated stroppings, but at all stages of wear some of the dispersed small abrasive particles are exposed at the surface, embedded in the plastic. I believe this better than the applying of rouge superficially to leather, as heretofore practiced, for the flexible plastic acts as any other suitable sheet material might do, to press back turned portions of the blades edge, and the rouge is more effective, being uniformly distributed and more permanently present than if it were merely dabbed on in superficial masses, as hitherto practiced; and the abrading by the rouge may be more regular and more effective, because of the firm embedding of each abrading particle.

In a simple arrangement for private use, herein illustrated, a small frame holds the blade, another holds the two strops, spring-pressed together. The user thrusts the frames together and apart, guided by rails which unite the frames loosely. A forward stroke of the blade carriage propels wedges that spread the strops apart, for the blades cutting edge to enter between them; and lets them clasp the blade back of its taper. Springs hold them pinching the blade with elastic pressure, while the blade is withdrawn and so is stropped on its backward travel.

In this stropping stroke the strops pinch-rub and abrade and bend to straightness the edge of the blade, with simultaneous opposed pressures that set the edge in the mid-plane of the blade. The strops may be of resilient material, each with a curved rubbing surface, so that, under their spring pressure, they bear along all of the blades cutting edge, and leave it in the desired medial position, by reason of the simultaneity of their opposite pressures. The curvature of the strops contacting surface may be attained by pre-shaping this part of the strop, or by bending each strop around the edge of a leaf spring which serves as a core; or has a separate core; and the shank of that spring is held clamped rigid in the apparatus. Thus the leatherrounded end of one strop is pressed against the leather-rounded end of the other strop. The holding of each strops stiff shank in a screw clamp permits of each strop being removed and exchanged for a fresh or a different strop.

At each strop, the ends of its core project transversely of the Sharpener as rounded hubs. Thus the strops of a pair can be spread apart by thrusting Wedges between the hubs of that pair. After the wedges have passed through between them, those released hubs spring back together. Hence at the end of the forward stroke of the wedges and blade, the released strops are pinching the blade behind the wedges.

For the withdrawal stroke, on which the blade is stropped, the wedges have to be extricatedi. e. gotten past the hubs-without separating the strops. The device for getting the wedges past the hubs from their final forward position back to their initial forward position, includes means to displace the wedges. In one illustrated species the wedges are rigidly attached to the blade carriage, and the wedge displacing is lateral from the path of withdrawal. In another instance the displacing is longitudinal. There is lost motion between the wedges and the blade carriage which propels them. These species, details of which appear later herein, have it in common that the wedges are driven from one side to the other side of the hubs while the strops continue pinching the blade.

The carriage has side rods, projecting fore and aft loosely into the strops-holder. These are rails which support the blade-carriage frame for movement to and fro in the strops-holding frame. The rails are attached by means which permit of their being set to suit different types of blades, according to their differing widths, so that in every case there can be proper timing for the wedges to separate the hubs before the blade reaches the strop. The wedges, mounted on the blade carriage in advance of the blade, receive the users positive propulsion against the hubs. In the blade carriage, magnetism may be provided to steady the blade preliminarily, and so to assist the user in positioning it properly for his clamping it there.

In the species in which the wedges are rigidly attached to the carriage, each wedge is a hollow wedge, made of leaf springs arranged in V-form, and these springs can be separated at the point of the V. On a forward drive they act as a wedge, separating the strop hubs, which then close behind them. On a backward drive the closed strop hubs become entrapped in the hollows of these V wedges and displace outward the spring walls thereof. These wedge walls close together to restore their V-form after their ends have passed the strop hubs. To` protect the strops from mismanagement by any user, who might push forward before he has fully extricated the hubs from within the long hollow wedges, a spring latch may be provided. This may be set in the side wall of the strop holder between the spring leaves that make the wedge, projecting thence inward enough to engage the hubs, and set enough in advance of the blade to guard the strops. Whenever the blade has passed out from between the strops, any forward stroke of the blade carriage will be stopped by the latches, safely before the blade reaches the strops, unless the points of the wedges have already passed the hubs, in which case the points enter between the hubs and separate the strops, as in a fresh stroke.

Alternatively the wedges may be solid. In this case each wedge is a block or button, each end of which is a Wedge. The blade carriage is` rigidly mounted on side rods that slide toand fro in the strop carriage and, for each wedge that is to separate the strops, there is an extent of its rod, limited by abutments, in a part oi the total travel of the rod, in which that wedge block can be moved idly. On a` forward stroke of the blade carriage the encounter of the block with the strop hubs makes that wedge block slide idly backward on the rod, until the limit of idle motion is reached, when the continued forward propulsion of the blade carriage drives the forward wedge-end of the block between the hubs, separating the strops while the blade enters, and letting them close together on the blade after the wedge blocks have passed through their hubs. Upon the blade-stropping withdrawal stroke, the encounter of the rear ends of the wedge blocks with the closed hubs displaces those blocks lengthwise, pushing each idly forward along the rod or rail on which it is strung, until the backward-moving abutment at the forward limit of travel of the wedge block forces the rearwardfacing wedge to separate the hubs to let the block through between them. The parts are located so that this does not happen until the blades edge has passed out from between the strops. The passing of the wedge block lets the strops close together, ready for a fresh forward stroke on which the wedge will slide idly backward, pushed by the strop hubs, until it reaches the rear abutment of the rail and is thereby forced forward to act as a wedge between the hubs as above described.

The wedge ends are rather blunt, pushing these blocks away very easily on their rails, within their extent of idle or lost motion, while encountering the spring-closed pair of hubs, but, when limiting abutments arrest this retreating, the positive propulsion of the users forward or rearward stroke requires them to act as wedges and to separate those spring pressed hubs, and to pass between them.

The apparatus may be arranged to: hold the strops and a blade rmly in any suitable way. Illustratively both are shown as being clamped removably but firmly by thumb screws. The bed which is to receive the blade may have size and shape to secure any of several popular sizes and shapes of blades. It may be magnetized so as to prevent the slipping of any blade that may be set upon it, while the user adjusts and clamps it into proper position for being stropped. In one embodiment a screw is illustrated for the clamping; but a construction for quicker operatio-n has merely a stiff hinged flap to cover the blade. This may be merely pinched by ones fingers to clamp the blade on its bed during the reciprocating push land pull of the sharpening.

In the sharpening apparatus thus described the rods that extend between the strop-holder and the blade carriage constitute rails that guide these two to and from each other when the user reciprocates them. There may be two sets of strops, between which the user will reciproca-te the carriage, to sharpen both edges at once of a double edged blade. On a forward stroke by the user, the Wedges separate the strops by positive propulsion; and then they let the strops clasp together upon the blade. This positive spreading of the strops at the approach of the blade assures that the strops will not become cut. An innocuous returning of the wedges, to their first position, is provided by making the wedges displaceable by the strop hubs, either laterally or longitudinally, while the strops are doing the stropping. Misuse, by any user essaying a forward stroke before complete return, is prevented by a spring latch. Variations of construction and arrangement may be made within the appended claims; and it is intended to express in them whatever features of patentable novelty are in the invention disclosed.

In the accompanying drawings, which illustrate embodiments of the invention,

Figure 1 is a plan, on an enlarged scale, of a sharpener for stropping both edges at once of a double edged blade, using solid wedges which are displaceable lengthwise from the strops during the stropping part of the stroke;

Figure 2 is a side elevation of the same, in medial section on the line 2-2 of Figure 1;

Figure 3 is a side elevation of the same, sectioned on line 3--3 of Figure 1, showing the blade carriage at substantially its extreme position to the left;

Figure 4 is a View similar to! Figure 3, showing the blade carriage in a position approaching the end of the movement to the right;

Figure 5 is a plan of 'another embodiment, in which the Sharpener is arranged to strop a blade, doing only one edge at a time; .also showing a type of wedge which is hollow and is displaceable laterally from the strops during the stropping part of the stroke;

Figure 6 is a side elevation of the same, in medial section on the line 6-6 of Figure 5;

Figure 7 is a plan of a Sharpener of the same general type as shown in Figures 5 and 6, arranged to hold a different shape of blade;

Figure 8 is a side elevation of the same, in section on the line 8-8 of Figure 7;

Figure 9 is a similar sectional elevation of the same, showing the cover closed upon the blade, but at the stage of stroke where the strops are about to be released from the wedge, to clasp the blade;

Figure 10 is a plan of a fragment of a Sharpener of the same general type as shown in Figures 5 and 6, arranged holding a blade of a very small plain type, the blade-cover being open;

Figure 11 is a side elevation of the same, in section on line I I-I I of Figure 10;

Figure 12 is a side elevation of the same, on a larger scale, in medial section on the line I2--I2 of Figure 10, but with the blade-cover closed, and showing the strops clasping the blade as at the beginning of the stropping stroke; and

Figure 13 is a plan of a Sharpener of the type shown in Figure 5, arranged to sharpen both edges of a double edged blade simultaneously.

It will be understood that, for clearness, the thickness of blades is necessarily exaggerated, and that the acuteness of cutting edges cannot be represented exactly.

Each strop Ill has leather, or other suitable strop material, at the end of a broad flat spring I2 whose shank I4 is clamped firmly in an end part of the apparatus, as by a thumb screw I6. The part of each strop I0 that is to bear against a blade is of soft leather, as suede or chamois, bent around the edge of the sheet spring I2 and enclosing there a core rod 30 which may be of brass or other stiff wire which holds the strop straight. The ends of this core project sidewise 0f the STOD and. constitute hubs 32, by which the strop can be lifted, bending the spring I2. And, as here represented, the core 30 is enclosed within a tube I5 of soft rubber, around which the said leather II is folded. 'Ihus each strop has a straight and stiff yet soft cylindrical surface to be rubbed clown over the taper, and off the eX- treme edge, of each blade that is to be sharpened. The basic firm pressure of the spring I2 against the equal and opposite basic pressure of a similar spring I2, the curvature which concentrates the pressure, and the intimate elastic flexibility of their backing I5, make the pinch-rubbing strops act upon all low points as well as high along the blades edge.

In the type represented in Figure 2 two strops I 0 are at each end of a frame I9; and a blade carriage 20 is reciprocable by the operator, having what is here called a forward stroke to thrust a cutting edge part of its blade 22 between the separated strops of a pair, which then clasp the blade behind the cutting edge; and having what is herein called a stropping stroke which then withdraws the edge from between the strops that are clasped upon that edge.

The blade 22 is of the familiar type having two opposite cutting edges 2I, 23; and there is a thumb screw 24 which clamps the blade 22 iirmly yet removably in the blade carriage 20. At its flanks, in channels in the strop-holding frame I 9, the blade carriage 20 has rigid parallel round rails 26 that extend forward and backward to penetrate and constitute bearings 28 to support the blade carriage in both end parts of th-e strop holding frame. On the bearings the blade carriage 2B can be pushed back and forth in the frame I9. Each rail 26, at each side of the blade carriage, carries a wedge block 29, strung loosely upon it, With free movement between abutments 34 and 36 that limit the travel of the block 29 on the rail; and the rails are aligned so that their blocks 29 acting as wedges can engage between the hubs 32 of each pair of strops, and can spread those hubs and their strops I0 while the cutting edge of a blade 22 enters between the strops, and, after the wedges have passed the strops, close upon the blade behind the wedges. Each said block 29 has a wedge end facing forward, and a wedge end facing backward. These wedges are rather blunt, illustrated at about 45, and each is so loose on the rail that it slides idly unless it is backed by one of its limiting abutments 34 or 36.

Since the strop hubs have round surfaces and stand a little distance apart, the blocks which are to be pushed between them, to separate them further, are not necessarily wedge shaped, but actual wedge shapes are preferable.

The rails are conveniently made of stiff straight wires, on which short tubes are secured in positions to constitute the abutments.

The wedges are conveniently made by provid-v ing thick cylindrical tubes and pointing their ends.

The users reciprocation of the blade carriage far from the blade carriage that the stropping of the blades edge is completed before the forward abutment begins to thrust the wedge backward between the strop hubs. Similarly the rear abutment 34 is located so that it forces the wedge to separate the strops before the cutting edge of the blade reaches the strops.

The portion of each strop which presses on 'the blade and does the actual rubbing preferably has a surface that is rather soft and. flexibly yielding, so that, under pressure, the surfaces of the strops conform to the shape of the surfaces on which they are pressing. Thus the two strops simultaneously, and with opposing pressures, pinch-rub the taper to the very extremity of the cutting edge. The desired softness of pressure may be attained by using a soft Variety of leather, or a soft plastic which may contain disseminated iine abrasive, such as rouge, or by providing the illustrated backing of elastic rubber between the leather and the core around which the leather is bent, at the edge of the sheet spring that carries the strop.

At the beginning of a forward stroke the wedge blocks will usually be at the forward end of their extent of loose and idle travel. As the blade carriage moves forward, the strop hubs idle the blunt wedges, by pushing them backward until they reach the rear abutments, whereupon the positive forward drive of those abutments overcomes the bluntness so that the wedges penetrate between the hubs, separate them while the blade enters between the strops, and then let the strops close to clasp the blade on the final part of the forward movement of the carriage. The withdrawal stroke then begins, with the stropping above described, being a gentle straightening or abrading applied by pressure of the sheet springs I2, on both sidessimultaneous and opposite-So that the cutting edge is. not thereby over-bent to either side of the median plane of the blade. Meantime during this stropping the closed hubs press the wedge blocks idly forward, as their respective rails move backward, until the forward abutments, moving backward, encounter and force those wedges backward between the strop hubs until the hubs again close. When the wedge blocks have thus passed the hubs backward, the next forward stroke follows immediately as above described.

In this structure the forward stroke of one edge of the blade is the backward or stropping stroke of its other edge. When the user has iinished his thrusting of the carriage back and forth, both edges will have been sharpened.

Alternative embodiments producing similar re- 4suits are shown in Figures 5-12. The blade carriages in these figures illustrate the holding of any of a variety of shapes of blades to strop only one cutting edge; also the clamping of the blade under a hinged cover; also wedges which can pass the hubs by becoming displaced laterally, being hollow and split.

The strops 50 of these gures may be as is described with reference to Figures 1-4, being sheet springs 52, whose Shanks are clamped by screws 54 in a strop holding frame 5S, and which have terminal surfaces of stropping material. The strop holding frame has a body portion 58, with serrated surface for firmness of grasp by the users fingers, and has deep longitudinal holes 69, one at each side, to receive and to constitute guides for rails 62, one at each side of the blade carriage 64, the end parts cf which rails slide 8 to`and fro in these holes as the blade 66 is thrust to and from the strops 50.

The bed part of the blade carriage 64 may be magnetized and thus, by holding the blade still on the bed, aids the user when he is inserting or removing the blade. As shown in these figures the blade carriage cover 'l0 is hinged for being opened or closed. Its external surface has roughness 'I2 to aid ones grasp when operating the Sharpener. The inner surface of the hinged cover is shaped to fit the blade. Thus it enables the mere grasp of the user to clamp the blade 66 firmly against the blade bed, when the cover is closed and the blade is in its allotted position. The blade shown in Figures 5 and 6 is of the twoedged type that has a long medial holding-slot parallel to its edges. The bed of the blade holder 64 has a corresponding channel 'I3 into which a bar 8U may be set with'its width projecting upward to enter said holding slot of any blade of this type; and this channel and its bar are arranged so as to locate the cutting edge of the blade 66 for cooperating properly with the strops as herein described. When the cover is open to the position shown in Figure 5, a blade set on the bed G4 will surround the bar Se and be positioned by it. After the user flips the cover 10 shut, his grasp of the blade holder will hold the blade securely, ready for being stropped.

The rails 02 are rigid rods projecting from the blade carriage to a distance which can be adjusted land be held by set screws 63, to set the edge, of whatever type of blade is to be sharpened, properly for cooperation with the strops. The stropseparating wedges 8l illustrated in these figures are mounted rigidly with respect to the blade carriage, and are each composed of two separable leaf springs that are set as cams in V-form, so that the point of the V can enter between the hubs, and so that these cams together can constitute a wedge that will separate the hubs Sd, as is seen in Figure l1, and thence can release the strops, which thereupon clasp the blade along and behind its cutting edge as is i dicated in Figure l2. On a forward stroke of the blade carriage the strop hubs 84 become separated, f rom what is seen in Figure 6; but when the hubs reach the ends of the cam ramps their springs 52 clasp them with opposing pressures on the blade 66, as can be understood by considering the changes of position of hubs, from Figure 6 to those seen in Figures 11 and 12. The frame of the blade carriage has channel shaped sides which project forward beside the path of reciprocation toward and from the strops, outside of the breadth of position occupied by the strops. The rails 62 project adjustably from the ends of these channels. Within these channels are 1ocated the cams 8l, constituting the V-form wedges. They are mounted on the middle wall 88 of each channel, these being the extreme side walls of the apparatus. These cams are aligned with the strop hubs 84. They are located so that, on a forward stroke, the spread hubs separate the strops before the cutting edge of the blade E6 reaches the strops; hold them separated while the blade enters between the strops; and then release the hubs in the end part of the forward stroke, for the strops to clasp the blade 56 back of its cutting edge. When the stropping stroke begins, the two hubs of a pair, being then lclose together, become entrapped between the two cam ramps over whose outer sides they, passed on the forward stroke. As the stroppng stroke proceeds, each pair of hubs encounters `the inner faces of those cam strips, and displaces those same strips laterally of the direction of stroke, splitting their V-wedge formation. When the hubs have passed through between them the strips return to their V-form, being made of spring material.

Figures 7, 8 and 9 represent arrangement to hold a blade of the type that carries on its back edge a folded plate 90. In these figures the groove 'I8 of Figure 8 holds a bar 92 with upstanding pins that lit into the holes by which blades of this type are secured.

Figure 9 shows how a blade cover, hinged at 94 as in Figures 5, 6, 7 and 8, may appear when it is closed. The hinge is not necessarily located at the particular edge which is here illustrated. The users grasp of the closed cover pinches the blade rmly for the sharpening.

Figures 10, 1l and 12 illustrate a similar securing of a very small plane blade |00. The blade bed |04 has a recess I8 for a bar 80, whose width upstands as above described beside the back edge |06 of the blade when it is set on the bed of the carriage. This with the frame constitutes 'retaining means for three edges of the inserted blade. The fourth edge of the blade has the cutting edge, which is slightly short of the full length of that fourth edge, as at |08; and this fourth edge is retained by small projections from the frame that engage the non-cutting end parts f of this edge. Thus a four-sided socket is formed, in which the users grasp retains such a blade.

However the apparatus itself may secure the blade; as is illustrated by Figures l0, 1l and 12. Herein the cover ||2 has a reversible control spring H4, to hold the cover firmly closed, or open. Pressure by the user on the thumb piece `l I6 opens the cover to the position of Figures l0 and 11; and opposite pressure closes it to the position of Figure l2.

Means for preventing misuse, by a person who might push the strops and blade together too soon, after the strops are off the blade but before the strop hubs have escaped from within the hollow wedge, is provided by a spring latch |20. This, as seen in Figures and 11, may be mounted on the middle wall of the channel 88 and is a leaf spring whose end portion is within the hollow of the wedge 8|, and projects into the path used by the strop hubs on the stropping stroke. This Vspring latch |20 yields to let the hubs pass it to accomplish a normal stropping stroke; but it -springs back into the path of the hubs, and is a barrier to movement of the blade in forward direction against the closed strops, in case a person inadvertently tries to move the blade for another stropping before the hubs have been removed from within the hollow wedge.

The elements thus described for the stropping -apparatus may be constructed mostly of metal,

but plastics or other materials may be used, and the combination may have its described elements associated in various ways. f

10 A suitable grasp of the blade being provided, the users simple driving of the frames back and forth makes the strops open, clasp the blade, and pinch-rub its edge.

For stropping a double-edged blade in half the time required for stropping its two edges separated, two arrangements are shown. As seen in Figures 1 4, the forward stroke of one blade-edge to its pair of strops is the backward or withdrawal and stropping stroke of the other edge, done by the strops'that are clasped on that other edge. In this arrangement the stropping of edges is alternate, and both are complete in one single operation comprising a few strokes.

For blades that have only a single edge the arrangement shown in Figures 5-12, is adapted. However, the carriage seen in Figures 5 and 6, can hold a two-edged blade. and this style can be designed to sharpen the two edges by merely repeating on the left of the blade the structure which is seen at its right. This is seen in Figure 13 where a blade 66, held in place by the bar |80 and cover, hinged at one end and latched closed at its other, |10, can be approached simultaneously by two pairs of strops |50, each mounted on stiff shanks |52. The user grasps the end frames |56, which are roughened for his convenience at |58 and with rapid motion reciprocates all strops simultaneously toward the blade and then apart from the blade. In this action there are guide rods |62 running in holes |60; and the strops have core rods and hubs |84 that control the strops, as in the other instances. When they are together the strops clasp both edges of blade; and as they are pulled apart they pinch-rub both edges of the blade simultaneously, with the same time-saving eect as in the case of Figures 1 4.

I claim:

l. A blade Sharpener comprising, in combination, two frames constructed and arranged with provision for one of them to slide to and fro within the other; springs and a pair of strops thereby held spring-pressed together in one of those frames, the pair of strops having, at their flanks, projecting hubs by which the strops may be separated; means in the other said frame to hold a blade with its cutting edge toward the strops; hubs-separating cams at the flanks of the blade holder, said cams having separate supporting means but being movable with the blade holder, said cams being aligned and set to reach and separate the hubs on forward stroke before the held blade reaches the strops, and to release the hubs from separation when the strops are in position to clasp the blade behind its cutting edge; the said clasping becoming, in the withdrawal stroke, a pinch-rubbing of the blades taper and cutting edge; each said cam being aligned to collide with and to pass its pair of said hubs, on the blades withdrawal stroke, but being displaceable by pressure of that collision while the blade continues clasped by the strops.

2. A blade Sharpener as in claim 1, in which one of the said frames has channelled side bars; said hub separators are within said channels; and the said provision to slide to and fro comprlses guide rails, fast to the blade holding frame and projecting loosely into the other frame.

3. A blade Sharpener as in claim 1, in which the said blade holding frame has, at each side, a projecting rail; and each said cam is a hubsseparating block loose for travel upon the rail, and each rail has abutments limiting that travel set for the one of those abutments to drive the block forward between the strop hubs, for the Il' blade to enter between the strops; the other f them being set to drive the block back between the hubs; and the Said looseness making the block displaceable along the rail, by the 'strop hubs, while the blade is being withdrawn from between the strops.

4. A blade Sharpener as in claim 3 in which each end of a said block is a 'Wedge for separating strop hubs.

5. A razor blade Sharpener as in claim 1, in which each pair of lhubs-separating cams is a wedge comprising a pair of leaf springs set in V-form, in advance of the blade, and adapted on forward stroke to enter between said hubs to spread them; the said displaceabilty of this Wedge by collision pressure on stropping stroke being by the elastic lateral yielding of its leaves.

6. A blade Sharpener as in claim 5 in which the blade holding frame has side bars with channels, e-xten'd-ing to the strop holding 'frame open toward the ends of the strop hubs, andthe said V-form spring leaves are located in those channels and have shank Iportions secured on the middle wall of the channel; and each said cam portion provides clear space at its end for the Y strop hub which it engages to spring to bladeclasping position.

7. A blade Sharpener comprising, in combination, two frames constructed and arranged with provision for one of them to slide to and fro within the other; a pair of strops, spring pressed together in one of 'those frames,v and hav-ing, at their anks, projecting hubs by which the strops may be separated; lmeans in the other said frame to hold la blade with its cutting edge toward the strops; and means on fthe blade holding frame to separate, and 'then to release, the strop-hubs, for the blade to enter, and then be clasped, and on withdrawal to be stropped, each said strop comprising a `sheet of spring material whose shank is clamped in 'the strop hold'- ing frame `land whose end is of `'stropping ymaterial and is by the said shank pressed toward the corresponding end ofthe other strop of the same pair; thereby, on withdrawal *of la blade that may n be clasped lby 'those strops, to pinch-rub 4'both sides of that blade.

`8. A blade Sharpener as in claim il -further jcharacterized .in that the said stropping material 'at the end of said sheet of spring material has 'an elastically yielding curved surface `for its strop- :ping contact with the bla-de.

9. A blade sharpener comprising, in combination, two pairs of strops; holders for 'those pairs, Spr-ings holding the strops of each ,pair 'springpressed together.; rails loosely penetrating the said holders, yand a carriage for a double edged blade on those rails, located between the rails and between the pairs of strops; the strop 'holders being movable toward each other on `the rails, for each to reach `an edge of the blade held on the carriage; each Astrop carrying outwardly -projecting hubs at its flanks for cooperation with separating elements; separating elements fixed to said blade holding carriage and movable therev with and arranged to separate and then release the strops on the forward stroke of the blade holding carriage; the release of said `strops being arranged to permit the strops to engage the blade rearwardly of the cutting edges thereof.

10. A 'blade Sharpener comprising, lin combination, two pairs of strops, holders for those pairs, springs holding the strops of each pair spring-pressed together; rails 4loosely penetrating the sadholders, and a carriage for 4a double edged blade on those rails, located between the rails and between the pairs of strops; said rails constituting guides for travel of the blade holder relative to each strop holder; each strop carrying outwardly projecting hubs at its flanks for cooperation with separating elements; vand separating elements xed to said blade holding carriage and movable therewith and arranged to separate and then release the strops on the forward stroke of the blade holding carriage; the release of said strops being arranged to permit the strops to engage the blade rearwardly of the cutting edges thereof.

11. A blade Sharpener comprising, in combination, two frames constructed and arranged with provision for one of them to slide to and fro within the other; springs; a pair of strops held spring-pressed together in one of said `frames by said springs; the pair of strops having at their flanks projecting hubs by which the strops may be separated; means in the other of Said frames to hol-d a blade with its cutting edge toward the strops; hub-separating cams at the flanks of the blade holder; said cams being supported on side bars on the blade-supporting frame and extending to the blade separating frame; said cams each Icomprising a wedge formed of a pair of leaf springs set in V-form, in advance of the blade; said leaf springs being aligned and set to enter between said hubs on the forward stroke to separate them before the held blade reaches the strops and to release the hubs from separation when the strops are in position to clasp the blade behind its cutting edge.; the said clasping becoming in the withdrawal stroke a pinch-rubbing of the blades taper and cutting edge; each said cam being aligned to collide with and to pass its pair of said hubs -on its withdrawal stroke, the displaceability of the cam by collision pressure of the stropping stroke being by the elastic lateral Vyielding of its leaves; and a spring latch on each side bar located between the V-form leaves, this latch being in alignment with said hubs and set to permit passage of said hubs on the withdrawal stroke of the blade from between the strops and thereafter on an approach of the blade to the strops, while the hubs are between lthe V-form .leaves of the wedge, to engage the hubs and arrest the approach.

12. A blade Sharpener comprising, in comblnation, two frames constructed and arranged with one of them having projecting side rails constituting guides to slide to and fro within the other; a pair of strops; each of said strops comprising va sheet of spring material Whose shank is clamped in one frame and whose end is 'of stropping material and being pressed by said shank toward the corresponding end of the other strop of the pair to pinch rub both sides of the blade when the blade is withdrawn; 'projecting hubs at their flanks by which the strops may be separated; means on the other frame including a magnetized bed to .hold fa blade with its cutting edge toward the strops; `means to clamp the vblade on said bed.; and hub separating elements xe'd to said blade-.holding frame and moving therewith and arranged to separate and then release the hubs on the forward stroke of said `blade-holding frame with the strops clasping theblade rearwardly of its cutting edge.

13. A blade Sharpener comprising, lin bombi- 'nation, two .frames constructed and arranged with one of them having projecting side rails constituting guides to slide to and fro within lthe other; a pair of strops; each of said strops comprising a sheet of spring material whose shank is clamped in one frame and whose end is of stropping material vand being pressed by said shank toward the corresponding end of the other strop of the pair to ypinch rub both sides of the blade when the blade is withdrawn; projecting hubs at their flanks by which the strops may be separated; means on the other frame to hold a blade with its cutting edge toward the strops; said blade holding means comprising a bed having `a groove across the direction of stroke; 'a bar fitting in said groove and extending above said bed and through an opening in a blade on said bed; means to clamp said blade to said bed; and hub separating elements xed to said bladeholding frame and movable therewith and arranged to separate and then release the hubs on the forward stroke of said blade-holding frame, the release of said hubs being arranged to permit the strops to engage the blade rearwardly1 of the cutting edge thereof.

14. A blade Sharpener comprising, in combination, two frames constructed and arranged with one of them having projecting side rails constituting guides to slide to and fro within the other; a pair of strops; each of said strops comprising a sheet of spring material whose shank is clamped in one frame and being pressed by said shank toward the corresponding end of the other strop of the pair to pinch rub both sides of the blade when the blade is withdrawn; projecting hubs at their flanks by which the strops may be separated; means on the other frame to hold a blade with its cutting edge toward the strops; said blade-holding means comprising a bed having edge walls upstanding to enclose four edges of a blade, the enclosing of the cutting edge being only at the ends of that edge and beyond the cutting portion of that edge; means to clamp the blade to the bed; and hub separating elements fixed to said blade-holding frame and movable therewith and arranged to separate and then release the hubs on the forward stroke of said blade-holding frame, the release of said hubs being arranged to permit the strops to engage the blade rearwardly of the cutting edge thereof.

15. A blade Sharpener comprising, in combination, two frames constructed and arranged with one of them having projecting side rails constituting guides to slide to and fro within the other; a pair of strops; each of said strops comprising a sheet of spring material whose shank is clamped in one frame and being pressed by said shank toward the corresponding end of the other strop of the pair to pinch rub both sides of the blade when the blade is Withdrawn; projecting hubs at their anks by which strops may be separated; means on the other frame to hold a blade with its cutting edge toward the strops; said blade holding means comprising a bed having upstanding means to prevent sliding of a blade thereon, a plate hinged to an edge portion of said bed and foldable over said bed, and hub separating elements fixed to said blade-holding frame and movable therewith and arranged to separate and then release the hubs on the forward stroke of said blade-holding frame with the strops clasping the blade rearwardly of the cutting edge thereof.

16. A blade sharpener comprising, in combination, a strop-carrying frame and a blade-holding frame constructed and arranged with provision for one of them to slide to and fro within the other; a pair of strops carried by said stropcarrying frame, means carried by said stropcarrying frame spring-pressing said strops together, said strops having, at their ilanks, projecting hubs by which the strops may be separated; means in the blade-carrying frame to hold a blade with its cutting edge toward the strops; and hub-separating cams mounted on said blade-holding frame at the anks of said frame and cooperable with the projecting hubs of said strops, said cams being movable with said blade-holding frame and being located and shaped to separate the hubs on the forward stroke with the strops in spaced blade-receiving relation and then, also on the forward stroke, to release the hubs to permit the strops to clasp the received blade, said cams being further displaceable out of hub-separating position by said hubs, during that portion of the withdrawal stroke within which the blade is between the strops.

17. A blade Sharpener comprising, in combination, two frames constructed and arranged with one of them having projecting side rails constituting guides to slide to and fro within the other; a pair of strops, means spring-pressing together said strops in one of those frames, having at their anks protecting hubs by which the strops may be separated; means in the other said frame to hold a blade with its cutting edge toward the strops; said blade holding means including hub-separating elements moving therewith and set to separate and then to release the hubs on forward stroke, this release being in position for the strops to clasp the blade behind its cutting edge.

18. A blade Sharpener comprising, in combination, two frames constructed and arranged with provision for one of them to slide to and fro within the other; a pair of strops, means to hold said strops spring-pressed together in one of those frames; means to hold a blade on the other said frame with its cutting edge toward the strops; strop-separating means on said last named frame for causing the blade to enter and be clasped between them, and means supporting said separating means on one frame and connected to the other frame for the separating means to be actuated by the propulsion of the frames together.

WALTER S. BUCK'LIN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,015,938 Brockhurst Jan. 30, 1912 1,034,422 Christiansen Aug. 6, 1912 1,048,571 Muth Dec. 31, 1912 1,543,386 Holtzrnan June 23, 1925 1,557,601 Magee Oct. 20, 1925 2,328,998 Radford Sept. 7, 1943 2,413,551 Englund Dec. 31, 1946 FOREIGN PATENTS Number Country Date 460,686 Great Britain Feb. 2, 1937 139,163 Great Britain Nov. 18, 1920

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