US2561025A - Brush of the push broom type - Google Patents

Description

My 37 3951 A. L. LE FEBVRE BRUSH OF THE PUSH BROOM TYPE '2 Sheets-Sheet l Filed June 7, 1946 ww l S\ INVENTOR. Alfred L Lef'b Vr@ BY ATTORNEY my 37, 1951 A. L LE FEBVRE 2,561,025

BRUSH oF THE- PUSH BRooM TYPE Filed June 7, 1946 2 sheets-sheet 2 lll/1111111 11,

INVENTOR. Alfred L .Lefebvre A TT 0RNE Y.

Patented July 17, 1951 .ation OFFICE sansnfor THE'PUSH BnooM'rYPE Alfred L. Le 'Febvre Windsor, Conn., assignor to The Fuller VVIarush Company, Hartford, Conn., a corporation of Connecticut Application ,J une 7,1946, Serial No. 675,236

17 Claims. i

This application is a continuation-'impart of my abandoned application for Fioor Brush of the Push Broom Type, Serial No. 594,471, filed May 18,1945.

The present invention is particularly applicab le to a brush of the push broom type,` but the invention is not necessarily so limited. A `brush embodying the invention includes a plurality .of brush stripseach comprising an elongated holder or channel member with bristles projecting therefrom, .the said strips being engaged with a suitable base which serves to hold them in proper relationship with each other.

One of the objects of the invention is to proyide a brush having a simple and inexpensive base for supporting and holding' the brush strips. Preferably and in accordance with one phase or" ,the invention, .the .base is formed of extruded materiaL ordinarily metal.

. Another object of thev invention is to provide a novel arrangement of brush strips, particularly at the ends of the brush, so as to provide amore effective distribution of the bristles.

Still another object of the invention is toy provide, in conjunction with the base and with the brush strips, end caps which serve to cover the ends of the base and the end portions oi the brush strips.

Still another object of the invention is to providean improved means for attaching ahandle to a brush of the type described.

yStill other objects of the invention will be apparent from the accompanying drawings and trom; the following specication and claims.

nIn .the drawings IV have shown in detail a .preferred embodiment of the invention, but it will be understood that various changes may be made from the construction shown,v and that the drawings are not to be construed as defining or limiting` JGhe scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

Of the drawings,

Fig. 1 is a plan view of a brush embodying .the inyention.

Fig. 2 is a side View.

Fig. 3 is an enlarged transverse sectional View taken along the line 3.-.3 of Fig. l.

Fig. 4 is an enlarged fragmentary longitudinal Isectional view taken along the line fi-t of Fig. l.

Fig. 5 is an enlarged fragmentary sectional View taken along the line 5-*5 of Fig. 2.

Fig. 6 is an enlarged transverse sectional View taken along the line 6-.6 of Fig. 1.

Fig, 1 is an enlarged Afragmentary longitudinal sectional View taken along the line 1-7! of Fig. 1.

Referring to the drawings, I0 represents the base of the brush which extends longitudinally throughout the major portion. of the brush length. The base may be varied in length as required. The base Iii is provided, preferably immediately adjacent its sides, with two longitudinal open-bottom grooves I2, I2 which are open at their ends. The grooves are narrowest adjacent their open bottoms and the side walls of the grooves converge downwardly toward the said narrowest portions. As shown, the grooves I2, Ii! are formed between downward extending longin tudinal anges I4, I 4 and I6, I6. The inner face of each flange I4 is vertical and the outer face of each iiange Iii lis inclined. Lines or planes lo cated midway 'between the said inner and outer faces of `the flanges are inclined in downward and outward directions.

Preferably, for a purpose to be presently stated, the base is provided between the flanges Il, It with oppositely inclined longitudinally extending faces. As Shown, the said oppositely inclined faces are the Vinner faces of the flanges It, I which face toward the center and are inclined so as to converge downwardly. The said inner faces of the flanges I6, I6 constitute the outer wallsI of two open-bottom longitudinal grooves which are substantially wider than the said grooves I2, I2. To conserve material the bottom edges of the flanges I5, .I6 may be provided with longitudinal grooves I8, I8.

The base ,I0 is preferably provided at the center with a longitudinal open-bottom groove 2o which is open at its ends. The groove is nar-rowest adjacent its open bottom and the side walls of the groove converge downwardly toward the said narrowest portion. As shown, the groove 2o is formed between downward extending longitudii nal flanges 22, 22, the inner faces of which converge downwardly.

While the invention is not necessarily so limited, the base I0 is preferably formed by extrusion, being of uniform cross section throughout. I do not limit myself as to the material for the basebut it may suitably be made from a light metal such as aluminum or magnesium or an Aalloy thereof. In the manufacture of brushes the bases Ii) therefor are cut to suitable lengths ,from long strips of the extruded material.

The brush includes a plurality of brush strips, portions of which are engaged with the grooves I2, I2 and with the groove 2G when such groove is provided. Each brush strip comprisesk ametallic member 24 which constitutes the holder for the bristles 2,6 of the strip, the said member being bent so that it is U-shaped in cross ksection and constitutes a channel, the bristles 26 being doubled within the U-shaped holder or channel member and being held by the walls of the member and by a central core wire 28. In the manufacture of the 'brush thev required brush strips are, cut to length from previously formed longer strips. It will be understood that the term bristles as herein used is intended to be generic 3 and to include bristles or fibers of any kind suitable for use in brush manufacture.

Entered endwise in the grooves I2, l2 are brush strip portions and 32, the holders 24 of the said strip portions engaging the converging side walls of the grooves above the narrow bottoms thereof so that the brush strips are firmly held against relative downward movement. The sizes of the holders 24 and of the grooves are so related that considerable force is required for the endwise insertion of the holders in the grooves. The resultant friction is sufficient to prevent any accidental or unintended removal of the holders from the grooves. Preferably the two strip portions 30 and 32 are connected by means of an integral end portion 34, the said portions 30, 34 and 32 being formed from a single main strip which is bent so that the portions 30 and 32 are substantially parallel. As shown in Figs. 3 and 4, the holder or the channel member of the brush strip is additionally bent so that transverse lines midway between the sides thereof are inclined in downward and outward directions and so that the bristles 26 are inclined in downward and outward directions. The angle of inclination is the same as the angle of the lines or planes midway between the sides of the grooves l2, I2. Preferably in the initial bending of the strip the portions 30 and 32 diverge slightly. Upon insertion into the grooves they are forced into longitudinal parallelism and this tends to increase the friotion-al resistance to removal of the holders from the grooves. Preferably strip portions such as 3B and 32 are inserted in the grooves l2, I2 in the base from both ends, and for convenience in manufacture each strip portion 32 is substantially longer than the strip portion 30. As shown in Fig. 1, this provides juncture points 36, 36 near the ends of the base. The brush may have any one of a variety of lengths and the length of the base IU is varied accordingly. For convenience in manufacture it is preferred to make the shorter strip portions 30 always of the same length regardless of the length of the brush, and to vary thelength of the longer strip portions 32 in accordance with the length of the brush.

In order that there may be a larger body of bristles at the ends of the brush I preferably provide at each end a supplemental brush strip which is bent to provide a connecting end portion 38 and two parallel portions 40, 40. This brush strip is preferably identical in construction with the brush strip already described, except that in bending the said Strip the central plane of the holder or channel member thereof is maintained in vertical position instead of being inclined. The spacing between the two brush strip portions 4U, 40 is such that the holders of the said portions can be firmly engaged with the 'downwardly converging faces of the flanges I6, i6 as shown in Fig. 3. 'Ihese converging faces serve to prevent relative downward movement of the strips. Each strip is initially bent with the portions 40, 40 slightly diverging, and these portions are forced into parallelism as the strip is inserted endwise, and this assists in resisting endwise removal of the strips.

When a central groove such as 20 is provided, brush strip portions are inserted therein in the manner already described in connection with the brush strip portions 36 and 32. Preferably there are two brush stripy portions 42, 42 which are inserted in the groove 20 from opposite ends thereof. Each brush strip portion 42 is similar in construction to the brush strip portions 30 and 32, but may differ therefrom in cross section, as shown in Fig. 3.

In order to cover the ends of the base and the parts of the brush strips which project beyond the said ends, I provide two end caps 44, 44. Each end cap is recessed as indicated at 46 to receive the end portion of the base I0 and each end cap is preferably provided with integral inward projections 48, 48 which engage the bottom of the base at the sides thereof. These projections 48 prevent upward movement of the cap relatively to the base. Each end cap 44 is suitably shaped to cover the connecting end portions 34 and 38 of the brush strips, and when the said connecting end portions are circularly curved, as shown, the end of the cap 44 is similarly curved.

In order to prevent endwise removal Vof the cap from the base the cap is providedv with a lug 50 which projects downward between the end of the base and the connecting end portions of the holders of the strips, as clearly shown in Figs. 4 and 5. The lug 50 may be recessed, as shown at 52, to receive the end portion of the corresponding brush strip 42. It will be seen that the lug 50 serves by reason of its engagement with the connecting end vportion 38 of the supplemental brush strip to firmly hold the cap in place. In assembling the brush the central brush strips 42, 42 are put in place first. Then the cap and the corresponding main and supplemental brush strips are preliminarily assembledwith each other and the entire preliminary assembly is forced endwise with respect to the base. After completion of assembly the said brush strips are held in place frictionally and the end cap is held in place by means of the lug 50.

Preferably the base Ill is provided with a, central transverse slot 54 which is open at the top and which communicates with the groove 23. A handle holding member 56 extends through the slot 54 and portions of the said member are seated in the groove 20 between the inner ends of the brush strips 42, V42 in the said groove. Preferably, the portions of the member 56 which are seated in the groove are pivot elements 58, 58 which enable the member 56 to move pivotally in the slot 54 about the pivotal axis of the said elements. A handle 60 is provided, this being connected with the handle holding member 56. Preferably and as shown, the handle holding member is threaded and the handle is provided with a threaded member 62 at its lower end which receives the threaded upper portion of the member 56. Carried by the base l0 is a bracket 64 which has an arcuate face 66 concentricl with the axis of the pivot elements 58 58. The bracket 64 has a slot 68 through which the member 56 extends. When the handle is loosely engaged, it can be adjusted to any relative angular position within the limits of the slot 68, and by then turning the handle about its own axis the threaded engagement of the member 62 with the member 56 forces the said member 62 into clamping engagement with the arcuate face of the bracket to lock the handle in its adjusted position. It will be understood that the bottom face of the member 62 is spherical in shape so as to provide suitable engagement with the arcuate face of the bracket for any rotative position of the handle. Certain details of the handle connection as shown and described do not constitute any part of the present invention, being set forth 'and claimed inl my copending application for Brush of theV Push Broom Type, Serial No. 714,681,

5; led December '7, 19.46, .as ya .continuation-impart of this .present application.

WhatI claim is:

1. In a brush of the type described, the combination of a rigid extruded .unitary base uniform vin .cross `section from end to end and provided with two .parallel integrally formed openbottom grooves which are open at .their ends and have downward converging side walls, and two similar brush elements each .comprising a holder U-shaped in cross section and having bristles projecting downward therefrom which holder vis bent ,to provide a .connecting .end portion beyond one end of the lbase and also to .provide two parallel portions, the said .parallel portions of the holders .being entered endwise in the saidgrooves from opposite ends thereof with their ends in substantially .abutting relationship .and .the said parallel portions `engaging the downward converging side walls of the grooves to prevent relative ldownward .movement and .being iirrnly held frictionally by .the .groove walls to resist endwise withdrawal.

.2. In a brush of the type rdescribed, the combination of a rigid extruded unitary base uniform `vcross section from end to end and provided with two parallel vintegrally formed open-bottom grooves which are open at their ends and .have downward converging side walls, and two similar brush elements each comprising a holder U- shaped in cross section and having bristles prc jecting downward therefrom which holder is bent to vprovide a connecting end portion beyond one end of the base and also to provide two parallel portions of diiferent lengths, the said parallel portions of the holders being enteredendwise in the said grooves from opposite ends thereof .with their ends in substantially abutting relationship and the said parallel portions engaging the down* ward converging side walls of the grooves -to prevent relative downward movementand being rn ly held frictionally by the groove walls to resist endwise withdrawal.

3. In a brush of the type described, the-combination of a rigid base provided'with two parallel longitudinal integrally formed vopen-bottom grooves which are narrowest adjacent their bottoms andare open at their ends and also provided with two integral longitudinal walls-spaced inward from the grooves and having similar oppositely inclined faces, a brush-strip comprising a holder U-shaped in-cross section and also comprising bristles projecting downward from the holder, the holder of the said strip being bent to provide a connecting end portion beyond one end of the base and to also provide two parallel portions which are entered endwise in the two grooves in the base and which engage with the side walls of `the 4grooves above the narrowest portions thereof, and a second brush strip similar to the first and having its holder similarly bent to provide a connecting end portion between the first said end portion and the corresponding end of the base and vto -also provide two parallel portions which are engaged by endwise movement with the said oppositely inclined faces on the base and are thus held in place.

4. In a brush of the type described, the combination of a base, a brush strip comprising a holder U-shaped in cross section and also coml prising bristles projecting downward from the holder, the holder of the said strip being bent to provide a connecting end portion beyond one end .of the baseand-.toalsoprovide two parallel portions which are engaged with the base at .the

bottom thereof, a second brush strip similar .to the first and having its holder similarly .bent to provide a connecting end portion between :the first said end portion and the corresponding end of the base and to .also provide two parallel portions which are engaged with the base at the bottom thereof and between the parallel portions. of the .first said strip, and a Vcentral brush strip comprising a .holder U-shaped .in cross section and .also comprising bristles projecting downward from the holder, the said .central strip having its holder positioned between the parallel portions of .the holders of the rst and second strips and engaged .with the base.

5. In a brush vof the type described, the combination of a rigid base provided with two parallel longitudinal integrally .formed open-bottom grooves which are narrowest adjacent their .bottoms and are open at their ends and also provided with two integral longitudinal walls spaced inward from the grooves and having similar oppositely inclined faces, the said base being further provided with a central longitudinal integrally .formed open-bottom groove which is nar.- rowest adjacent its bottom and is open at 'its ends, a brush strip comprising a holder U-shaped in cross section and also comprising bristles'projecting downward from the holder, the holder of the said strip being bent to provide a connecting end portion beyond one end of the base and to also provide two parallel portions which are entered endwise inthe iirst said grooves in the base and which engage the side Walls of the grooves above the narrowest portions thereof, a second brush strip similar to the rst and having its holder similarly bent to provide a connecting end portion between the first said end portion and the corresponding end of the base and to also provide two parallel portions which are engaged by endwise movement with the said oppositely inclined faces on the base and are thus held in place, and a central brush strip comprising a holder U-shaped in cross section and also corn-- prising bristles projecting downward from the holder, :the said .central strip being positioned between the lparallel portions of the rst and second strips and having its holder entered endwise inthe central groove in the base in engage# ment with the side walls thereof above `the nar rowest portion.

6. In a brush of the type described, the com-- bination of a base, a brush strip comprising a channel strip U-shaped in cross section andhaving bristles projecting downward'therefroin which holder is bent to provide a connecting endportion beyond one end of the base and two parallel portions which engage the base, the said holder being further-bent so that transverse lines midway between the sides of all portions thereof are inclined in downward and outward directions, and a second brush strip similar to the first and having its holder bent to provide a connecting end portion between the first said end portion and the corresponding end of the base and to also provide two parallel portions which engage the base between the parallel portions of the rst said holder, the second said brush strip having the transverse lines midway between all portions thereof perpendicular to the bottom of the base.

`7. VIn a brush of the type described, the com` bination of a rigid base having two parallel integrally formed open-bottom grooves which grooves are open at their ends and have downward converging walls so disposed that ,planes midway vbetween the walls of the respective grooves diverge in the downward direction, and a brush strip comprising a holder U-shaped in cross sections and having bristles projecting downward therefrom which holder is bent to provide a connecting end portion beyond the end of the base and two parallel portions and which is further bent so that planes midway between the sides of the two parallel portions of the holder diverge in the downward direction in conformity with the aforesaid diverging midway planes of the grooves in the base, the said parallel portions of the holder being entered endwise in the said grooves in the base and engaging the downward converging walls of the said grooves.

8. In a brush of the type described, the coinbination of an extruded base uniform in transverse cross section and provided'with two longitudinal open-bottom grooves which are narrowest adjacent their bottoms, the said base being also provided with two longitudinal walls spaced inward from the grooves and having similar oppositely inclined faces, a brush strip comprising a holder U-shaped in cross section and also comprising bristles projecting downward from the holder', the holder of the said strip being bent to provide a connecting end portion beyond one end ofthe base and to also provide two parallel portions which are entered endwise in the two grooves in the base and which engage with the side walls of the grooves above the narrowest portions thereof and the said parallel portions being firmly held frictionally by the groove walls to resist endwise withdrawal, and a second brush strip similar to the first and having its holder similarly bent to provide a connecting end portion between the first said end portion and the corresponding end of the base and to also provide two parallel portions which are engaged by endwisemovement with the said oppositely inclined faces on the base and are thus held in place.

. 9. For a brush of the type described, an eX- truded base uniform in transverse cross section and provided with two longitudinal open-bottom grooves which are narrowest adjacent their bottoms and also provided with two longitudinal open-bottom grooves substantially wider than the rst said grooves and spaced inwardftherefrom, the last said grooves having their respective outer faces converging in the downward direction, the said base being also provided between the said wider grooves with a central longitudinal open-bottom groove which is narrowest adjacent its bottom.

10. The combination in a brush of the type described, of a base, a brush strip comprising a holder U-shaped in cross section and also comprising bristles projecting downward from the holder, the holder of the said strip being bent to provide a connecting end portion beyond one end of the base and to also provide two parallel portions which are engaged with the base at the bottom thereof, and a cap projecting beyond the end of the base and recessed to receive and nt the end portion of the base, the said cap being shaped to cover and closely i'it the parts of the holder which project beyond the base.

ll. The combination in a brush of the type described, of a base, a brush strip comprising a holder U-shaped in cross section and also comprising bristles projecting downward from the holder, the holder of the said strip being bent to provide a connecting end portion beyond one end of the base and to also provide two parallel portions the holders of which are engaged with the base at the bottom thereof, and a cap projecting beyond the end of the base and recessed to receive and t the end portion of the base and provided with integral inward projections which engage the bottom of the base at the sides thereof, the said cap being shaped to. cover and closely nt the parts of the holder which project beyond the base.v

12. The combination in a brush of the type` described, of a base having two parallel integrally formed open-bottom grooves which are narrowest adjacent their bottoms and are open at their ends, a` brush strip comprising a holder U-shaped in cross section and also comprising bristles projecting downward from the holder, the holder of the said strip being bent to provide a connecting end portion beyond one end of the base and to also provide two parallel portions which are entered endwise in the two grooves in the base and which engage with the side walls of the grooves above the narrowest portions thereof, and a cap projecting beyond the end of the base and recessed to receive and t the end portion of the base and provided with integral inward projections which engage the bottom of the base at the sides thereof, the said cap being shaped to cover and closely nt the parts of the holder which project beyond the base and the said cap being provided with a lug projecting downward between the end of the base and the connecting end portion of the holder and serving to lock the cap in place.

13. In a brush of the type described, the combination of a base provided with two parallel longitudinal integrally formed open-bottom grooves which are narrowest adjacent their bottoms and are open at their ends and also provided with two integral longitudinal walls spaced inward from the grooves and .having similar oppositely inclined faces, a brush strip comprising a holder U shaped in cross section and also comprising bristles projecting downward from the holder. the holder of the said strip being bent to provide a connecting end portion beyond one end of the base and to also provide two parallel portions which are entered endwise in the two grooves in the base and which engage with the side walls of the grooves above the narrowest portions thereof, a second brush strip similar to the rst and having its holder similarly bent to provide a connecting end portion between the iirst said end portion and the corresponding end of the base and to also provide two parallel portions which are engaged by endwise movement with the said oppositely in clined walls on the base, and a cap projecting beyond the end of the base and recessed to receive and nt the end portion of the base and provided with integral inward projections which engage the bottom of the base at the sides thereof, the said cap being shaped to cover and closely t the parts of the two holders which project beyond the base and the said cap being provided with a lug projecting downward between the end of the base and the connecting end portion of the second holder and serving to lock the cap in place.

14. In a brush of the type described, the combination of a base provided with two parallel longitudinally integrally formed open-bottom grooves which are narrowest adjacent their bottoms and are open at their ends and also provided with a central longitudinal integrally formed open-bottom groove which is narrowest adjacent its bottom and is openy at its ends, a brush strip comprising a holder U -shaped in cross section and also comprising bristles projecting downward 9 from the holder, the holder of the said strip being bent to provide a connecting end portion beyond one end of the base and to also provide two parallel portions which are entered endwise in the rst said grooves in the base and which en gage the side walls of the grooves above the narrowest portions thereof, a central brush strip comprising a holder U-shaped in cross section and also comprising bristles projecting downward from the holder, the holder of the said central strip being positioned between the parallel portions of the holder of the rst strip and being entered endwise in the central groove in the base in engagement with the side walls thereof above the narrowest portion, and a cap projecting beyond the end of the base recessed to receive and t the end portion of the base and provided with integral inward projections which engage the bottom of the base at the sides thereof, the said cap being shaped to cover and closely t the parte of the first said holder which project beyond ne base and the said cap being provided with a lug projecting downward between the end of the base and the connecting end portion of the rst said holder and serving to lock the cap in place which lug has a longitudinal groove for receiving the end of the holder of the central brush strip.

l5. In a brush of the type described, the combination of a rigid base provided with two parallel longitudinal integrally formed open-bottom grooves which are narrowest adjacent their bottoms and are open at their ends and also provided with two integral longitudinal walls spaced inward from the grooves and having similar oppositely inclined faces, the said base being further provided with a central longitudinal integrally formed openbottom groove which is narrowest adjacent its bottom and is open at its ends, a brush strip comprising a holder U shaped in cross section and also comprising bristles projecting downward from the holder, the holder of the said strip being bent to provide a connecting end portion beyond one end of the base and to also provide two parallel portions which are entered endwise in the first said grooves in the base and which engage the side walls of the grooves above the narrowest portions thereof, a second brush strip similar to the first and having its holder similarly bent to provide a connecting end portion between the rst said end portion and the corresponding end of the base and to also provide two parallel portions which are engaged by endwise movement with. the said oppositely inclined faces and are thus held in place on the base, a central brush strip comprising a holder U-shaped in cross section and also comprising bristles pro jecting downward from the holder, the said cenm tral strip being positioned between the parallel portions of the rst and second strips and having its holder entered endwise in the central groove in the base in engagement with the side walls thereof above the narrowest portion, and a cap projecting beyond the end of the base recessed to receive and t the end portion of the base and provided with integral inward projections which engage the bottom of the base at the sides thereof, the said cap being shaped to cover and closely t the parts of the rst and second holders which project beyond the base and the said cap being provided with a lug projecting downward beu tween the end of the base and the connecting porn tion of the second holder serving to lock the cap in place which lug has a longitudinal groove for 0 Number receiving the end of the holder of the central brush strip.

16. In a brush of the push broom type, the combination of a base provided with two parallel longitudinal integrally formed open-bottom grooves near its sides which are narrowest adjacent their bottoms and are open at their ends and also provided with a central longitudinal integrally formed open-bottom groove which is narrowest adjacent its bottom and is open at its ends, the said base having a central opening extending downward from the top and communieating with the last said groove, brush strip portions each comprising a holder U-shaped in crosssection and each also comprising bristles projecting downward from the holder, the holder of each strip portion being entered endwise in one of the side grooves in the base and engaging with the side walls thereof above the narrowest portions, two central brush strips each comprising a holder U-shaped in cross section and also comprising bristles projecting downward from the holder, the holders of the said central strips being entered endwise from opposite ends in the central groove in the base in engagement with the side walls thereof above the narrowest portion, and a handle holding member extending through the central opening inthe base and entering the central groove at both sides of the said openings and between the holders of the brush strips in the said groove.

17. In a brush of the push broom type, the combination of a base provided with a central longitudinal integrally formed open-bottom groove which is narrowest adjacent its bottom and is open at its ends, the said base having a transverse central slot extending downward from the top and communicating with the last said groove, two central brush strips each comprising a holder U-shaped in cross section and also comprising bristles projecting downward from the holder, the holders of the said central strips being entered endwise from opposite ends in the central groove in the base in engagement with the side walls thereof above the narrowest portion, a handle holding member extending through the central opening in the base and having pivot elements entering the central groove at both sides of the said opening between the brush strips in the said groove. and a handle secured to the handle holding member and pivotally movable therewith about the axis of the said pivot elements.

ALFRED L. LE FEBVRE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Trautrnan Sept. 14, 1915 Kogler Sept, 25, 1928 Fitzgerald Aug. 20, 1929 Lofstrand July 12, 1938 Zehetner Apr. 30, 1940 Brock July 2, 1940 Ross Mar. 18, 1941 FOREIGN PATENTS Country Date Great Britain Dec. 1'7, 1894 Number

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