US2691252A

US2691252A - Knife sharpener

Info

Publication number: US2691252A
Application number: US228610A
Authority: US
Inventors: George C Punton
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-05-28
Filing date: 1951-05-28
Publication date: 1954-10-12
Anticipated expiration: 1971-10-12

Description

Oct. 12, 1954 G. C. PUNToN 2,691,252

KNIFE SHARPENER Filed May 28, 1951 3 Sheets-Sheet l INVENTOR. .IGEORGE 0. PUNTO/V AGENT Oct. l2, 1954 G. c. PUNToN KNIFE SHARPENER Filed May 28, 1 951 3 Sheets-Sheet 2 INVENTOR. GEORGE C. PUNTO/V AGENT Oct. 12, 1954 G. c. PUNTON .KNIFE SHARPENER 3 Sheets-Sheet 5 Filed May 28, 1951 INVENTOR. GEORGE C. PUNTON Patented Oct. 12, 1954 UNITED STATES PATENT OFFICE 12 Claims.

My invention relates to a knife Sharpener, more particularly to a knife Sharpener adapted for use in precision filing and grinding of knife blade edges used in butcher shops or other production wherein knives are used, and the objects of my invention are:

First, to provide a knife Sharpener of this class which is capable of very quickly providing a precise sharp edge on a knife by removing a minimum amount of material therefrom;

Second, to provide a knife Sharpener of this class having means for adjusting the cutting or grinding spindles to the desired angle for concurrently machining opposite sides of a knife blade edge without particular attention of the operator thereto; j Third, to provide a knife Sharpener of this class having a plurality of opposed axially diverging files and a plurality of axially diverging grinding spindles, which are synchronized in their diverging angle so that adjustment thereof causes correspondence of the angle of the diverging files with the angle of the diverging grinding spindles, permitting a knife to be filed and subsequently ground to a high degree of finish without changing the machining angle dictated by the desired cutting edge angle of the blade;

Fourth, to provide a knife Sharpener of this class which may be used for sharpening variousv cutting instruments, such as knives, cleavers, or other tool, by adjusting the le and grinding spindles accordingly;

Fifth, to provide a knife Sharpener of this class having a particular arrangement of grinding spindles, wherein the axes of the spindles are staggered and in opposed relationship to each other, permitting opposed surfaces of these spindles, axially of a knife blade, to be adjusted as desired without peripheral interference of the grinding spindles;

Sixth, to provide a knife Sharpener of this class having a plurality of opposed diverging grinding spindles, and means for concurrently rotating and reciprocating said grinding spindles longitudinally of their axes, whereby the grinding operation performed upon knife blade edges does not tend to form grooves in said grinding spindles or wear the same unevenly;

Seventh, to provide a knife Sharpener of this class having a plurality of opposed diverging knife edge machining spindles, provided with guards therearound exposing only the peripheral portion of said spindles, whereby the machining of a knife blade may be precisely controlled by said guides, which prevents undue machining of the knife blade edge during sharpening thereof;

Eighth, to provide novel means for angularly adjusting a plurality of opposed diverging knife edge machining spindles;

Ninth, to provide a knife Sharpener of this class which is particularly adapted to save considerable time in sharpening knives, and to provide a very fine, precise, keen edge thereon with a minimum amount of attention on the part of the operator sharpening the knives; and

Tenth, to provide a knife Sharpener of this class which is very simple and economical of construction, efficient in operation, and which will not readily deteriorate or get out of order.

With these and other objects in view, as will appear hereinafter, my invention consists of certain novel features of construction, combination and arrangement of parts and portions, as will be hereinafter described in detail and particularly set forth in the appended claims, reference being had to the accompanying drawings and to the characters of reference thereon, forming a part of this application, in which:

Fig. 1 is a top or plan view of my knife sharpener; Fig. 2 is a side elevational View thereof, showing portions broken away to amplify the illustration; Fig. 3 is a bottom plan sectional view, taken from the line 3-3 of Fig. 2; Fig. 4 is a transverse sectional View, taken from the line 4-4 of Fig. 2; Fig. 5 is a fragmentary sectional view, taken from the line 5 5 of Fig. 4, showing the structure on enlarged scale; Fig. 6 is an enlarged fragmentary sectional view, taken from the line 6-6 of Fig. 4; Fig. 7 is a perspective View of the assembly of the le spindles of my knife Sharpener; and Fig. 8 is a fragmentary sectional View, taken from the line 8 8 of Fig. '7.

Similar characters of reference refer to similar parts and portions throughout the several views of the drawings.

The motors 2 and 3, supported in the frame i, provide for the operation of the

grinder spindles

5, 6, 'l and 8, and the file spindles 9, I0, II and I2, by means of the belts I3, Id and I5. It will be noted that the motor 2 is provided with a shaft 2a, on which the pulley 2b is fixed. This pulley 2b is a double grooved pulley with which the belts I3 and I4 are engaged. The motor 3 is provided with a shaft 3a having a pulley 3b fixed thereon, and engaging this pulley 3b is the belt I5. The idler pulleys 35 and 3l,

' 33 and 39, are stationary pulleys engaging the belts I3, I4 and I5 for directing the same relative to the pulleys of the

grinder spindles

5, 6, 'I' and 8, and the file spindles 5, ill, H and i2. The idler pulleys 3G, 3l and 38 are stationarily iixed to the frame I, while the idler pulley 3S is supported on the track frame 2? by means of the depending bracket 2id, all as shown best in Fig. 2 of the drawings.

The grinder spindles 5, 6, l and are provided with pulleys 2S, 58, 29 and SI, respectively, secured to the lower ends thereof, and the pulleys are engageable with the belts S3 and i4, as shown best in Fig. 3 or" the drawings. t will be noted that the belt i4 passes over the idler 3l and the

pulleys

28 and 30, while the belt I3 passes over the idler 36 and over the pulleys 29 and 3 I The belt I5, engaging the

idlers

35 and 35, passes over the

pulleys

32, 33, 54 and 35, on the lower ends of the file spindles 9, I5, li and l2, respectively. The spindle bearing supports i6 and Il` are provided with intermeshing nger portions Ia and Ila, in which the nie spindles 9, it, H and I2 are rotatably mounted. It will be noted that the file spindles I5 and i2 are rotatably mounted in the nger portions Iia of the spindle bearing support i6, while the iile spindles 9 and I I are rotatably mounted in the nnger portions Ila of the spindle bearing support Il.

The opposite ends of the spindle bearing support l1, as shown in Fig. '7 oi the drawings, are fixed in the channel-shaped track frames 25 and 2 by means of the set screws 25a. Likewise, the spindle bearing support iii is mounted at its opposite ends in the channel-shaped in

cross-section track frames

24 and 25, which are rigidly interconnected by the bar 26a. Thus parallel alignment of the track frames 24 and 2B is maintained. The

track frames

25 and 2l, 20 and 22 and 2| and 23 are interconnected in a similar manner.

The ends of the

track frames

24 and 25 are pivotally interconnected by means of the pin 25?), and the ends of the track frames 26 and 2l are pivotally connected by means of the pin 25e. The track frames 25 and 2i are pivotally interconnected =by a pin similar to the pin 25h, while the track frames 22 and 231 are also pivotally connected by means of a pin similar to the pin 25h hereinbefore described.

All of the spindle frame supports i6, Il, I8 and I9 are maintained in fixed relationship with their respective track frames by means of set screws similar to the set screw 25a. hereinbefore described and illustrated in Figs. 7 and 8 of the drawings.

The spindle assembly frame 54 provides a support for the

track frames

24, 25, 25 and 21, and the pin 25h extends through the side 54a of said spindle assembly frame 54, and a similar pin 25e on which the spindle frames 26 and 2 are pivoted, extends through the side 54h of the spindle assembly frame 54. As shown in Fig. fi, the spindle assembly frame 55 is mounted in channel tracks la and ib of the frame l, and similar tracks at the opposite end of the frame I support the spindle assembly frame 54, hereinbefore described.

The

spindle assembly frames

54 and 55 are slidably mounted in the tracks of the frame i, so that the spindle assemblies may be readily removed from the frame i, as desired.

It will be noted that the springs 45 and 46a are secured to downwardly depending arms connected with the track frames 2?, 2i, 22 and 23, tending to pivot the same on the pins similar to the pins 25h and 25e illustrated in Fig. 7 of the drawings. Thus, these

springs

40 and 40a tend to angularly diverge the

grinding spindles

5, 6, l and 8, and cause the cam portions 22a, and 23a connected with the

spindle frames

22 and 23, to engage the wedge 48, which is mounted on the screw 49, in screw-threaded relationship therewith. The screw 49 is maintained against endwise movement in the frame I, and is rotatably mounted, so that the wedge 48 is caused to longitudinally traverse the screw 4S when it is rotated by the hand wheel 50.

The wobble plate 5I is provided with an upper concave surface 5Ia, and is pivotally mounted in the frame I on the axle 52, as shown best in Fig. 4 of the drawings. The link 53 pivotally connects the wobble plate 5l with the crank disc 4a on the shaft of the motor 4, which is adapted to cause the wobble plate 5I to pivot back and forth over the axis of the axle 52, which is stationarily mounted in the frame i.

The link 42 interconnects the track frames24 and 26 and the track frames 85 and 22, inasmuch as the link 42 is pivotally connected at one end to the arm 24a and at the other end to the arm 20a. `The link 43 interconnects the track frames 25 and 2l and track frames 2| and 23 by its pivotal connection at one end to arm 25d and at the other end to arm ZIa. Thus it will be seen that the movement of

track frames

24 and 26 are synchronized with the movement of

track frames

20 and 22 and similarly the movement of track frames 25 and 2l are synchronized with the movement of track frames 2l and 23. The operation of the wedge 48 therefore causes pivotal divergence or convergence of the file spindles 9, In, II and I2 identical to that of the grinding spindles 5, B, 'i and 8.

The

spindle guards

44 and 45 are substantially L-shaped, as shown in Fig. 5 of the drawings, and are secured at their base portions to the spindle bearing supports I8 and i9 by means of the screws 45a passing through slots 44a, which provide for adjustment of these

spindle guards

44 and 45 relative to the axis of the

grinding spindles

5, 6, 'I and 8. It will be noted that the spindle guard 45 is adjacent to the grinding spindles 1 and 8, while the spindle guard 44 is adjacent the

grinding spindles

5 and 6. It will be noted that each of these

spindle guards

44 and 45 is provided with notch portions therein, which substantially receive and surround the

grinding spindles

5, 6, 'I and 8.

The

grinding spindles

5 and 6 axially diverge relative to the grinding spindles 'I and 8, and the peripheral portions of these

grinding spindles

5, 6, 'I and 8 project very slightly beyond the face portions of the

spindle guards

44 and 45. The spindle guard 45, as shown in Fig. 5 of the drawings, is provided with aface 45h, which may be spaced a small fraction of an inch from the peripheral surface 5a of the grinding spindle 8. The same relationship applies to the grinding spindle 5 and the spindle guard 44, so that a knife inserted between the

spindle guards

44 and 45 may be ground to a predetermined depth without damaging the knife edge and removing an undue amount of material therefrom.

The construction of the spindle guards 46 and 4l, adjacent to the ille spindles 9, l0, II and I2, is substantially similar to the

spindle guards

44 and 45, hereinbefore described.

Each of the grinding spindles 5, G, l and 8 is provided with a supporting shaft and bearings all similar in construction. The grinding spindle 8, as shown in Fig. 5, is provided with a shaft 8b, having a pair of 'bearing

races

8c and 8d, which are mounted in the spindle bearing support I9. ISecured to the shaft 8b lis the pulley 3I,`and surrounding the shaft 8b is the spring 8g, which engages a thrust bearing 8e, all of which tends to force the shaft 8b downwardly into engagement at its lower end 8f with the upper surface Sla of the wobble plate 5|.

It will be noted that the shaft 8b is slidably mounted in the inner races of the

bearings

8c and 8d, in order to provide axial reciprocal movement of the grinding spindle 8 caused by action of thewobble plate 5I.

The operation of my knife Sharpener is substantially as follows:

When it is desired to sharpen a knife, in using my knife Sharpener, the motors 2, 3 and 4 are operated by closing the

switches

56 and 51,

shown best in Fig. 1 of the drawings. When the motors 2, 3 and 4 are operating, the

pulleys

2b and 3b drive the belts I3, I4 and I5, causing rotation of the file spindles 9, I0, II and I2, and the

grinder spindles

5, 6, 'l and 8. Assuming that a knife blade is very rough, it is placed between the le spindles II and I2, as shown in Fig. 2 of the drawings, in engagement with the spindle guards 46 and 4l, and is drawn therethrough. The slight peripheral projection of the le spindles II and I2 beyond the guards 46 and 4l causes the knife blade to be filed at opposite converging edges. The knife blade may then be drawn between the pair of grinding spindles l and 8 -and the pair of grinding

spindles

5 and 6, adjacent to the spindle guards 44 and 45, which finishes the edge on the knife blade. During rotation of the grinding

spindles

5 and 8, together with the spindles 5 and l, the motor 4, by means of the crank disc 4a, link 53 and wobble plate 5I, causes the grinding spindles 6, 'I and 8`to reciprocate axially, which prevents peripheral grooves being worn in' said grinding spindles during their engagement with the knife blade supported intermediate the spindle guards

y

44 and 45.

The upper curved surface 55a of the wobble plate 5I, during pivotal movement on the axle 52, alternately forces the shafts of the grinding

spindles

5, 6, 'I' and 8 upwardly through the spindle bearing supports 'I8 and i9. The springs 8g return the shafts 8h downwardly with each reciprocal movement, while the thrust bearings 8e prevent twisting of the springs 8g.

When it is desired to adjust the angular relai tionship of the diverging grinder and lfile spindles, the hand wheel' 5l) is rotated, causing rotation of the screw 49, which axially adjusts the wedge 48, acting on the arms 22a` and 23a fixed to the spindle bearing supports I8 and I9. The

links

42 and 43, as hereinbefore described, cause synchronized adjustment of the spindle bearing supports I8' and llover the axes of the pins 25h and 25e, sor that the diverging angle to which a knife blade is subjected is the same intermediate the le spindles and the grinding spindles, for preliminary cutting andy nish grinding.

The springs 4D and 4I tend to hold the axes of the grinding spindles and the file spindles in ac-d cordance with the engagement of the wedge 48 by the arms 22a and 25a, hereinbefore described. The set screws 25a, as shown in Fig. 8 of the drawings, permit the spindle bearing supports I6 and I7 to be adjusted relative to each other for spacing or crossing the axes of the le spindles, while similar set screws permit the relative adjustment of the spindle bearing supports I8 and I9 in the track frames 20, 2|, 22 and 23, for similarly adjusting the axes of the grinding spindles. The spindle guards 44 and 45, as shown in Fig. 1 of the drawings, at their lowermost L-shaped portions, are provided with slots 44awhich are longitudinally adjustable over the screws 45a, in order to promote the setting of the spaces of the spindle guards in slight spaced relation to the peripheral portions of the grinding spindles, in order to predetermine the depth of cut on a blade inserted between said spindle guards 44 and `45, when sharpening the same.

Though I have shown and described a particular construction, combination and arrangement of parts and portions, I do not wish to be limited to this particular construction, combination and arrangement, but desire to include in the scope of my invention the construction, combination Iand arrangement substantially as set forthv in the appended claims.

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

l. In a knife Sharpener, a'plurality of blade surfacing cylindrical spindles arranged in axially diverging relationship to each other, said spindles being mounted for rotation about their axes, guards for said spindles exposing only a; slight portion of the peripheral surfaces of said spindles for controlling the depth of machining on a blade inserted between said guards and said spindles during rotation of said spindles, and means for rotating and axially reciprocating said spindles.

2. In a knife Sharpener, a plurality of blade surfacing cylindrical spindles arranged in axially` diverging relationship to 'each other, said: spindles being mounted for rotation about their' axes, guards for said spindles exposing only `a slight portion of the peripheral surfaces of said spindles for controlling the depth of machining on a blade inserted between said guards and said spindles during rotation of said spindles, means for rotating and axially reciprocating said spindles, bearings for said spindles, and spindlebearing supports for holding said bearings, individually pivotal relative to eachother,

for changing the diverging angle of said spindlesv relative to each other.

3. In a knife Sharpener, a plurality of blade surfacing cylindrical spindles arranged in axialv ly diverging relationship to each other, said spindles being mounted for rotation about their axes, guards for said spindles exposing only a slight portion of the peripheral surfaces of saidv spindles for controlling the depth of machining on a blade inserted between said guards and said` spindles during rotation of said spindles, means for rotating and axially reciprocating said spindles, bearings for said spindles, spindle bearing supports for holding said bearings individually pivotal relative to each other, for changing the diverging angle of said spindles relative to each other, and means for moving said spindle bearing supports toward or away from each other, comprising overlapping fingers in which said bearings are supported, whereby the axes of said spindles may be moved toward or away from each other for accommodating various blades and thicknesses thereof.

4. In a knife Sharpener, a` plurality of blade,

surfacing cylindrical spindles arranged in axially diverging relationship to each other, said spindles being mounted for rotation about their axes, guards for sa'id spindles exposing only a slight portion of the peripheral surfaces of said spindles lor controlling the depth of machine on a blade inserted between said guards and said spindles during rotation of said spindles, means for rotating and axially reciprocating said spindles, bearings for said spindles, spindle bearing supports for holding said bearings individually pivotal relative to each other, for changing the diverging angle of said spindles relative to each other, means for moving said spindle bearing supports toward or away from each other, comprising overlapping lingers in which said bearings are supported, whereby the axes of said spindles may be moved toward or away from each other for accommodating various blades and thicknesses thereof, and means for pivoting said spindle bearing supports. for adjusting the diverging angle of said spindles.

5. In a knife Sharpener, a plurality of blade surfacing cylindrical spindles arranged an axially diverging relationship to each other, said spindles being mounted for rotation about their axes, guards for said spindles exposing only a slight portion of the peripheral surfaces of said spindles for controlling the depth of machining on a blade inserted between said guards and said spindles during rotation of said spindles, means for rotating and axially reciprocating said spindles, bearings for said spindles, spindle bearing supports for holding said bearings individually pivotal relative to each other, for changing the diverging angle of said spindles relative to each other, means for moving said spindle bearing supports toward or away from each other, comprising overlapping lingers in which said bearings are supported, whereby the axes of said spindles may be moved toward or away from each other for accomodating Various blades and thicknesses thereof, means for pivoting said spindle bearing supports for adjusting the diverging angle of said spindles, and secondary spindle bearing supports having secondary blade machining spindles in connection therewith, and link means interconnecting said .first-mentioned spindle bearing supports and said second-mentioned spindle bearing supports for synchronizing the adjustment of the diverging angle of said first-mentioned spindles and said second-mentioned spindles.

6. In a knife Sharpener, a plurality of blade surfacing cylindrical spindles arranged in axially diverging relationship to each other, said spindles being mounted for rotation` about their axes, guards for said spindles exposing only a slight portion of the peripheral surfaces of said spindles for controlling the depth of machining on a blade `inserted between said guards and said spindles during rotation of said spindles, means for rotating and axially reciprocating said spindles, bearings for said spindles, spindle bearing supports for holding said bearings individually pivotal relative to each other, for changing the diverging angle of said spindles relative to each other, means for moving said spindle bearing supports toward or away from each other, comprising overlapping fingers in which said bearings are supported, whereby the axes of said spindles may be moved toward or away from each other for accommodating various blades and thicknesses thereof, means for pivoting said spindle bearing supports for adjusting the diverging angle of said spindles, secondary spindle bearing supports having secondary blade machining spindles in connection therewith, and link means interconnecting said first-mentioned spindle bearing supports and said second-mentioned spindle bearing supports for synchronizing the adjustment of the diverging angle of said first-mentioned spindles and said second-mentioned spindles, all of said spindles having pulleys in connection therewith, and liexible belts engaging said pulleys for rotating all of said spindles.

'7. In a knife sharpener, a plurality of blade surfacing cylindrical spindles arranged in axially diverging relationship to each other, said spindles being mounted for rotation about their axes. guards for said spindles exposing only a slight portion of the peripheral surfaces of said spindles for controlling the depth of machining on a blade inserted between said guards and said spindles during rotation of said spindles, means for rotating and axially reciprocating said spindles, bearings for said spindles, spindle bearing supports for holding said bearings individually pivotal relative to each other, for changing the diverging angle of said spindles relative to each other, means for moving said spindle bearing supports toward or away from each other, comprising overlapping fingers in which said bearings are supported, whereby the axes of said spindles may be moved toward or away from each other for accommodating various blades and thicknesses thereof, means for pivoting said spindle bearing supports for adjusting the diverging angle of said spindles, secondary spindle bearing supports having secondary blade machining spindles in connection therewith, and link means interconnecting said lirst-mentioned spindle bearing supports and said second-mentioned spindle bearing supports for synchronizing the adjustment of the diverging anglel of said firstmentioned spindles and said second-mentioned spindles, all of said spindles having pulleys in connection therewith, and flexible belts engaging said pulleys for rotating all of said spindles, said spindle bearing supports having tracks in which said bearings are adjustable, spindle assembly frames for said tracks, and a main frame in which said spindle assembly frames are slidably mounted.

8. In a knife Sharpener, a pair of pivoted spindle bearing supports having intermeshing ngers, spindle bearings mounted in said lingers, grinder spindles rotatably mounted in said spindle bearings, tracks for said spindle bearing supports pivoted on an axis aligned with said overlapping linger portions, `and means for adjusting the angular divering relationship of the axes of said grinder spindles by pivoting said tracks.

9. In a knife Sharpener, a pair of pivoted spindle bearing supports having intermeshing lingers, spindle bearings mounted in said lingers, grinder spindles in said spindle bearings, tracks for said spindle bearing supports pivoted on an axis aligned with said overlapping linger portions, and means for adjusting the angular diverging relationship of the axes of said grinder spindles by pivoting said tracks, guard means adjustable laterally of the axes of said grinder spindles, adapted to substantially surround the same and expose only a small portion of the surface of said grinding spindles, said guards being opposed to each other and adapted to support a knife blade therebetween, which may be sharpened by the exposed portions of said grinder spindles.

10. In a knife Sharpener, a pair of pivoted spindle bearing supports having intermeshing fingers, spindle bearings mounted in said lingers,

9 grinder spindles in said spindle bearings, tracks for said spindle bearing supports pivoted on an axis aligned with said overlapping nger portions, and means for adjusting the angular diverging relationship of the axes of said grinder spindles by pivoting said tracks, guard means adjustable laterally of the axes of said grinder spindles, adapted to substantially surround the same and expose only a small portion of the surface of said grinding spindles, said guards being opposed to each other and adapted to support a knife blade therebetween, which may be sharpened by the exposed portions of said grinder spindles, and means for axially reciprocating and simultaneously rotating said grinder spindles.

11. In a knife Sharpener, a pair of pivoted spindle bearing supports having intermeshing fingers, spindle bearings mounted in said fingers, grinder spindles in said spindle bearings, tracks for said spindle bearing supports pivoted on an axis aligned with said overlapping finger portions, and means for adjusting the angular diverging relationship of the axes of said grinder spindles by pivoting said tracks, guard means adjustable laterally of the axes of said grinder spindles, adapted to substantially surround the same and expose only a small portion of the surface of said grinding spindles, said guards being opposed to each other and adapted to support a knife blade therebetween, which may be sharpened by the exposed portions of said grinder spindles, and means for axially reciprocating and simultaneously rotating said grinder spindles, said means comprising a wobble plate having an upper concave surface engageable with the lower ends of said spindles.

12. In a knife Sharpener, a pair of pivoted spindle bearing supports having intermeshing ngers, spindle bearings mounted in said lingers,

10 grinder spindles in said spindle bearings, tracks for said spindle bearing supports pivoted on an axis aligned with said overlapping finger portions, and means for adjusting the angular diverging relationship of the axes of said grinder spindles by pivoting said tracks, guard means adjustable laterally of the axes of said grinder spindles, adapted tosubstantially surround the same and expose only a small portion of the surface of said grinding spindles, said guards being opposed to each other and adapted to support a knife blade therebetween, which may be v'sharpened by the exposed portions of said grinder spindles, and mea-ns for axially reciprocating and simultaneously rotating said grinder spindles, said means comprising a wobble plate having an upper concave surface engageable with the lower ends of said spindles, said spindles having pulleys near their lower ends and flexible belts engaging said pulleys.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 386,544 Johnson et al July 24, 1888 1,007,951 Hunter Nov. 7, 1911 1,134,587 Callahan Apr. 6, 1915 1,426,911 Rogers Aug. 22, 1922 1,933,640 Schafer Nov. 7, 1933 2,124,646 Barsch July 26, 1938 2,181,923 Smolarek Dec. 5, 1939 2,294,715 Bruno Sept. 1, 1942 FOREIGN PATENTS Number Country Date 2,603 Great Britain Sept. 14, 1867' 155,914 Great Britain Dec. 29, 1920 474,100 Great Britain Oct. 26, 1937