US3512745A

US3512745A - Artist's easel

Info

Publication number: US3512745A
Application number: US750820A
Authority: US
Inventors: Cletus W Gress
Original assignee: CLETUS W GRESS
Current assignee: CLETUS W GRESS
Priority date: 1968-08-07
Filing date: 1968-08-07
Publication date: 1970-05-19
Anticipated expiration: 1987-05-19

Description

Mina-1910* C.W.GRESS 3,512,745

ARTIST S VEASEL Filed Aug. 7, 1968 v I s Sheets-Sheet 1 INVENTQR. CLETUS w. GRESS C. W. GRESS ARTIST'S EASEL May-.19, .1910

Filed Aug. 7", 1968 n b i k SSheetS-Sheet 2 INVENTOR.

CLETUS W GRESS l! 1970 c. w GRESS 3,512,745

'ARTIST'S EASEL Filed Aug. 7. 1968 v 3 Sheets-Sheet 5 INVENTOR.

CLETUS w GRESS 3,512,745 ARTISTS EASEL Cletus W. Gress, 3636 4th Ave., San Diego, Calif. 92103 Filed Aug. 7, 1968, Ser. No. 750,820 Int. Cl. A47b 97/08 US. Cl. 248-449 10 Claims ABSTRACT OF THE DISCLOSURE An improved artists easel having two Opposing T- square clamps, cross members of which contain a shaped slot and piercing points to engage the work pieces in nonslip relationship; long extensions of the clamps being held parallel to each other on either side of a common support by spring-loaded eccentric cams with accessible release levers; the common support being centered on a rotational pivot oriented at 90 to the long clamp extensions which passes through and is aifixed to a perpendicular plate containing rollers with axes oriented along radii centering on the rotational pivot, and through a pivot hole in a second perpendicular detent plate which contains multiple pairs of elevated ridges or simple depressions which mate with the circumferences of the rollers to form rotational detent stops when the two plates are parallel and held together by spring compression acting along the center line of the rotational pivot; the detent plate being fixedly attached to a perpendicular elevation roller plate which contains rollers with axes oriented along radii centering on a perpendicular elevation pivot hole through which passes an elevation pivot which is fixedly attached to a perpendicular elevation detent plate which contains multiple pairs of elevated ridges or simple depressions which mate with the circumferences of the rollers to form elevation detent stops when the two elevation plates are parallel and held together by spring compression acting along the center line of the elevation pivot; the elevation detent plate being fixedly attached to a pair of long parallel support slides which move up and down freely in recesses in an I pedestal unless locked in position by a pair of eccentric cams which are operated by a foot lever and linkage; the I pedestal rising obliquely from two foot supports and forming a base to which are attached two foldable feet which, for stowage, may be parallel to the I pedestal or, in use, may be locked in rigid support extension with the outermost ends at approximately 60 arc of separation.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to an easel-like mechanical support system for panels, artists boards and framed canvasses, etc., which provides vertical adjustment and two axial adjustments, one of which may be either concentric or eccentric to match the users positional preference.

According to the invention, an adjustable mechanical support system has a basic support structure having a pair of foldable feet from which an extensible support column controlled by one or more regenerative cams extends upward at an oblique angle and terminates in a horizontal elevation pivot bar. A detent-positioned elevation structure rotates around the elevation pivot bar and supports a second pivot at a 90 relationship to the elevation pivot. A detent-positioned rotational structure rotates around the second pivot and supports a pair of cam-locked T-square clamps with slots and piercing points to hold flat panels, artists boards, framed canvasses, etc., at various distances from a supporting plant in various degrees of elevation from the vertical to the horizontal and at various degrees of concentric or variable eccentric rotation in the plane of elevation.

' United States Patent 1 "ice An object of the present invention is to provide a rugged, versatile support for panels, artists boards, framed canvasses, etc., which positions a vertical projection of the center of gravity within the central area of an equilateral triangle formed by extended feet and is therefore stable.

Another object of the invention is the provision of adjustment linkage by which panels, etc., may be moved up or down and locked at any non-incremental position.

Still another object of the invention is the provision of multiple incremental adjustments of the arc of elevation of the panels, etc., from vertical to horizontal without secondary manual locking mechanisms and which is achieved by forcibly overcoming the positive positioning of multiple spring-loaded detent stops.

Yet another object of the invention is the provision of multiple incremental adjustments of the rotation of the panels, etc., around an axis perpendicular to the plane of the panels, etc., without secondary manual locking mechanisms and which is accomplished by forcibly overcoming the positive positioning of multiple spring-loaded detent stops.

A still further object of the invention is the provision of clamping devices by which the panels, etc., may be positively in a non-incremental manner with a perpendicular axis of rotation passing through the geometric center of the panel or through any other eccentric point on the panel.

An additional object of the invention is the provision of clamping devices with serrated grooves and/or piercing points to prevent slippage of the panels, etc., when rotated in any position around a horizontal pivot.

A further additional object of the invention is to provide an easel-like mechanical support for panels, artists boards, framed canvasses, etc., which is simple and inexpensive to manufacture and assemble and is extremely durable.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIG. 1 is a perspective view partially exploded of a preferred embodiment of the present invention;

FIG. 2 is a perspective view partially exploded of the I pedestal of the preferred embodiment (FIG. 1);

FIG. 3 is a perspective view partially exploded of the elevation mechanism from FIG. 1;

FIG. 4 is a perspective view partially exploded of the rotation and clamping mechanisms from FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to FIG. 1, basic unit 11 is divided into two separate major sub-assemblies, clamp frame 12 and base assembly 13. The base assembly 13 is supported by ro

tatable feet

14a and 14b which are held to foot supports 16a and 16b by spring-loaded

pivot bolts

17a and 17b so that the rotatable feet can be rotated around the pivot bolts to a position parallel with the I support pedestal 21 for purposes of compact shipping and stowage. Latches 18a and 18b hold the rotatable feet rigid in normal use. Cam release pedal 19 is pivoted on two supports between the foldable feet by which cams 33a and 33b can be tightened or loosened. Cams'33a and 33b are supported front and back by

pivot bars

32a and 32b. Elongated support slides 41a and 41b are fitted on each side of and slide within the recessed portion of the I support pedestal 21 so that cams 33a and 33b may be rotated to wedge the support slides 41a and 41b in any desired vertical extension. A fixed elevation detent plate 44 is firmly eonnected to support slides 41a and 41b and contains multiple detent positions so that clamp frame assembly 12 may be positioned at various convenient angles of elevation when pivoted on spring-loaded pivot bolt 51 and held captive by spring 52, washer 53 and nut 54.

The clamp frame 12 consists of rotatable elevation roller plate 46 which is in contact with the fixed elevation detent plate 44. Elevation roller plate 46 also contains a detent mechanism which allows rotation of clamp frame 12 through a full 360 arc. Central clamp support 68 of this mechanism serves as a common slide guide for clamp assemblies 81a and 81b, which may be clamped firmly against the upper and lower edges of an artists board or a frame holding the artists canvass by means of

cams

73a and 73b.

FIG. 2 shows the I support pedestal 21 with its parts in rotated exploded orientation. Removable front 22 is shown with the cam release pedal 19 projecting through slot 27. Removable front 22 is connected by means of screws 24a and 24b entering mating holes 26a and 26b on T structure 23. Slot 28 extends from the bottom of the top of T structure 23 and contains within it the push bar 29 and a compression spring 31 by which the push bar 29 is held firmly against the end of cam release pedal 19. Front pivot bar 32a on the removable front 22 and rear pivot bar 32b on the T structure 23, receive

cam pivots

36a and 36b around which eccentric wedging cams 33a and 33b rotate in an eccentric manner, the rotation being controlled by the position of cam levers 34a and 34b which contain slots that receive push bar pin 37. Small arrows show the simultaneous operation of the articulated members when cam release pedal 19 is depressed to release the eccentric wedging cams 33a and 33b. Cam levers 34a and 3412 move freely in clearance slot 38 which is provided in the removable front 22. Dowels 39a and 3% are typical dowel guides which are held firmly captive to the T structure 23.

The upper portion of base. assembly 13 is shown in FIG. 3 with elongated support slides 41a and 41b held in parallel relationship by spacer block 43. Said elongated support slides contain dowel grooves shown typically at 42a and 42b which fit over and assume a sliding relationship with typical dowel guides 39a and 3%, respectively, as shown in FIG. 2. Fixed elevation detent plate 44 is shown in exploded rotated relationship with its mating member, rotatable elevation roller plate 46. These two are held in pivoted relationship by means of a spring-loaded pivot bolt 51 which enters the pivot hole 49. Said fixed elevation detent plate contains multiple pairs of heavy

metallic staples

47a and 47b, 470, etc., which cooperates to form matched detent depressions for

detent rollers

48a, 48b and 48c, shown partially recessed into the rotatable elevation roller plate 46. These multiple staples form convenient detent locations to allow elevation variation between the detent plate 44 and roller plate 46 through an arc of at least 90. Rotatable elevation roller plate 46 also contains a bolt clearance slot 56 and

mating holes

57a, 57b and 570 for attachment of a fixed rotation detent plate 59 (FIG. 4).

FIG. 4 illustrates the various parts of clamp frame assembly 12 in exploded relationship, the major parts being the fixed rotation detent plate 59, the clamp support assembly 64, the clamp assembly, upper 81a (not shown) and clamp assembly lower 81b. The fixed rotation detent plate 59 contains a multiplicity of metallic staple pairs 61a, 61b and 610 in matched relationship to roller positions 61a (not shown), 62b and 620, located in the hidden surface of rotatable roller plate 63.

Screws

58a, 58b and 580 pass through fixed rotation detent plate 59 and :mate with

holes

57a, 57b and 570 (FIG. 3) to hold the detent plate firmly against rotatable elevation roller plate 46 (see FIG. 3). Rotatable roller plate 63 is held in spring-loaded pivotal relationship to fixed rotation detent plate 59 by means of spring pivot bolt 66 which passes through pivot hole 67 and is held captive by a means of a spring, was-her, and nut (not shown). The central clamp support 68 is held vertical to the back surface of rotatable roller plate 63 by means of attaching screws 69a, b, c and d. Front pivot supports 71a and 71b and rear pivot supports 72a and 72b position

eccentric wedging cams

73a and 73b adjacent to and parallel with the left (not shown) and right faces of the central clamp support 68. These cams are supported and rotate eccentrically around

cam pivots

74a and 74b and are controlled in rotation by cam levers 76a and 76b which are held in a locked position by

tension springs

77a and 77b.

The central clamp support 68 contains on each face a pair of captive guide dowels 78a and 78b which mate with dowel grooves 79a and 7911, respectively, in clamp bar 82 of clamp assembly 81b. When cam lever 76b is moved downward against the spring tension, the clamp bar 82 can be inserted between the central clamp support 68 and eccentric wedging cam 73b, and can be positioned at any convenient vertical location and locked by eccentric wedging cam 73b when cam lever 76 is released.

Clamp assembly 81b includes a cross head 83 to which are attached clamp strips 84a and 84b adjacent to a serrated clamp groove 86 dimensioned to penetrate and firmly grip the thinner boards used by artists. Cross head 83 is fixed attached in a relationship to clamp bar 82 and contains metallic points 8701 and 87b for penetrating canvass covered wooden frames normally used by artists for holding the frames captive when the clamp frame assembly is rotated to any angle.

OPERATION Referring now to all of the figures, it can be seen that a panel, artists board, framed canvass, etc., can be clamped by the piercing points 87 or serrated clamp grooves 86 of the clamp assemblies 81 so that it is firmly held when the clamp bars 82 are in a horizontal position and that the panel may be clamped up or down, left or right, relative to the center of central clamp support 68 from which projects the spring pivot bolt 66. Clamp assemblies 81 are firmly held in desired positions by

eccentric wedging cams

73a and 73b with a regenerative action, i.e., a slight compressive bow in the panel, etc., acts to push the clamps 81 apart, but any motion in that direction causes the eccentric wedging cams 73 to rotate and apply a greater locking pressure against the clamp bars 82, thereby resisting the motion. Locking positions being non-incremental, are infinitely variable and may be released by cam levers 76. Should the user decide to rotate the panel, etc., he may forcibly overcome the spring-loaded positive positioning of rollers 62 resting on staple pairs 61 and rotate the roller plate 63 relative to detent plate 59 through an incremental arc until the rollers engage another matched set of staple pairs. In like manner, should the user decide to vary the elevation arc of the panel, etc., he forcibly overcomes a similar detent action between roller plate 46 and detent plate 44 and elevates or depresses the entire clamp frame 12 through an incremental arc until the rollers engage another matched set of staple pairs.

Should the user desire to raise or lower the panel, etc., he depresses cam release pedal 19 releasing eccentric wedging cams 33 while manually supporting the movable mass, re-positions it, and releases pedal 19 which allows spring 31 to act on cam levers 34 and re-lock eccentric wedging cams 33 which act in a regenerative manner against the force of gravity. Feet 14 may be released at locks 18 and rotated upward around pivot bolts 17 to create a more compact configuration for storage and shipment.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure which do not further fixedly clamping said Work pieces, said long constitute departures from the spirit and scope of the member having at least one guide means extending invention.

The invention claimed is: 1. A mechanical support system for supporting and orienting work pieces therein comprising:

a rotatable support member to which an easel head is fixedly attached, said easel head comprising two T-square clamps with supporting and locking structures for same;

a fixed rotation support member for cooperation with member are coupled in load-bearing relationship with axial alignment by which means rotation is prevented when spring bias is not forcibly overcome;

parallel to a long edge along at least one surface thereof;

a clamp support member for cooperation with said T-square clamps comprising an elongated strip having at least one complementary guide means extending parallel to a long edge along each of two opposite parallel sliding surfaces thereof for effect ing a parallel sliding relationship with the guide said rotatable support member and having a fixed means of said T-square clamps; central axis; first and second wedging means mounted in operable one of said rotatable support member and said fixed proximity to said clamp support member for forcing rotation support member having a plurality of rollers a locking engagement of said first and second T- positioned in fixed radial relationship to the central quare clamps against the parallel sliding surfaces axis thereof and the other of said rotatable support of said clamp support member and each of said first member and said fixed rotation support member and second wedging means having a lever projection having a plurality of complementary recesses in fixed for manual urging of said locking engagement; radial relationship to the central axis thereof; spring bias means urging locking engagement of said a rotatable coupling means coupling said rotatable sup- T-square clamp against said clamp support member; port member to said fixed rotation support member at least one elongated support slide to which said clamp and effecting a load-bearing proximity relationship support member is fixedly attached in oblique relaand axial alignment between said rotatable support tionship and having at least one guide means extendmember and said fixed rotation support member; ing parallel to a long edge along at least one surface spring bias means urging the positioning of said rollers thereof;

within said recesses when said rotatable support a support pedestal for cooperation with said elongated member and said fixed rotation support member are support slide comprising an elongated strip having at coupled in a load-bearing relationship with axial least one complementary guide means extending paralignment by which means rotation is prevented when allel to a long edge along at least one of two parallel spring bias is not forcibly overcome; sliding surfaces thereof for effecting a parallel sliding a pedestal stand to the top of which said fixed rotation relationship with the guide means of said elongated support member is fixedly attached in an oblique support slide; relationship. at least one wedging means for each said elongated 2. A mechanical support system for supporting and support slide mounted in operable proximity to said orienting work pieces therein comprising: support pedestal for forcing a locking engagement of a rotatable elevation support member having a central said elongated support slide against one parallel axis of rotation and to which an easel head is fixedly sliding surface of said support pedestal and each attached, said easel head normally comprising two said wedging means having a lever projection for T-square clamps with supporting and locking strucmanual urging of said locking engagement; tures for same; spring bias means urging locking engagement of said a fixed elevation support member for cooperation with elongated support Slide ag Said pp Pedestal; said rotatable elevation support member and having a pedal member mounted in operable proximity to a fixed central axis; said support pedestal; one of said rotatable elevation support member and a transfer linkage connected between said pedal memsaid fixed elevation support member having a plu- 5 ber and at least one of the said wedging means by rality of rollers positioned in fixed radial relationwhich motion of said pedal member effects motion ship to the central axis thereof and the other of said of said wedging means; rotatable elevation support member and said fixed a base member comprising two foot support members elevation support having a plurality of complementto which said support pedestal is fixedly attached in ary recesses in fixed radial relationship to the central an oblique relationship; axis thereof; two rotatable feet attached to the foot support members a rotatable coupling means coupling said rotatable eleof said base member and extensible to form an aP- vatio support member to said fixed elevation supproximate equilateral triangle around a vertical port member and effecting a load-bearing proximity projection of the center of gravity of all aforemenrelationship and axial alignment between said rotattioned members; able elevation support member and said fixed elevatwo compression spring biased pivot bolts effecting an tion support member; abutted rotational relationship between said foot spring bias means urging the positioning of said rollers support members and said rotatable feet;

within said recesses when said rotatable elevation two locking means by which said foot support memsupport member and said fixed elevation support bers may be fixedly coupled to said rotatable feet to prevent rotation in the extended position of said rotatable feet. 4. A mechanical support system for supporting and orienting work pieces therein comprising:

at least one elongated support slide to which said a rotatable support member to which an easel head clamp support member is fixedly attached in oblique is fixedly attached, said easel head comprising two relationship and having at least one guide means ex- T-square clamps with supporting and locking structending parallel to a long edge along at least one tures for same; surface thereof. a fixed rotation support member for cooperation with 3. A mechanical support system for supporting work 7 said rotatable support member and having a fixed pieces therein comprising: central axis;

first and second T-clamps each having a long member one of said rotatable support member and said fixed and a cross member, said cross member having at rotation support member having a plurality of rollers least one serrated groove for receiving and fixedly positioned in fixed radial relationship to the central clamping work pieces and having piercing means for axis thereof and the other of said rotatable support member and said fixed rotation support member having a plurality of complementary recesses in fixed radial relationship to the central axis thereof;

a rotatable coupling means coupling said rotatable support member to said fixed rotation support member and effecting a load-bearing proximity relationship and axial alignment between said rotatable support member and said fixed rotation support member;

spring bias means urging the positioning of said rollers within said recesses when said rotatable support member and said fixed rotation support member are coupled in a load-bearing relationship with axial alignment by which means rotation is prevented when spring bias is not forcibly overcome;

a rotatable elevation support member having a central axis of rotation and to which said fixed rotation support member is fixedly attached with central axis of same at ninety degrees to the central axis of said rotatable elevation support member;

a fixed elevation support member for cooperation with said rotatable elevation support member and having a fixed central axis;

one of said rotatable elevation support member and said fixed elevation support member having a plurality of rollers positioned in fixed radial relationship to the central axis thereof and the other of said rotatable elevation support member and said fixed elevation support having a plurality of compl mentary recesses in fixed radial relationship to the central axis thereof;

a rotatable coupling means coupling said rotatable elevation support member to said fixed elevation support member and effecting a load-bearing proximity relationship and axial alignment between said rotatable elevation support member and said fixed elevation support member;

spring bias means urging the positioning of said rollers within said recesses when said rotatable elevation support member and said fixed elevation support member are coupled in load-bearing relationship with axial alignment by which means rotation is prevented when spring bias is not forcibly overcome;

a pedestal stand to the top of which said fixed elevation support member is fixedly attached.

5. A mechanical support system for supporting and orienting work pieces therein comprising:

a clamp support member for cooperation with first and second T-square clamps comprising an elongated strip having at least two opposite parallel sliding surfaces for effecting a planar sliding relationship with said conventional T-square clamps;

first and second wedging means mounted in operable proximity to said clamp support member f r forcing a locking engagement of said first and second T- square clamps against the parallel sliding surfaces of said clamp support member and each of said first and second wedging means having a lever projection for manual urging of said locking engagement;

spring bias means urging locking engagement of said T-square clamp against said clamp support member;

a rotatable support member to which said clamp support member is fixedly attached and having a central axis of rotation;

a fixed rotation support member for cooperation with said rotatable support member and having a fixed central axis;

one of said rotatable support member and said fixed rotation support member having a plurality of rollers positioned in fixed radial relationship to the central axis thereof and the other of said rotatable support member and said fixed rotation support members having a plurality of complementary recesses in fixed radial relationship to the central axis thereof;

at least one elongated support slide to which said fixed elevation support member is fixedly attached and having at least one long planar surfac a support pedestal for cooperation with said elongated support slide comprising an elongated strip having at least one long planar surface for elfecting a planar sliding relationship with said elongated support slide;

at least one wedging means for each said elongated support slide mounted in operable proximity to said support pedestal for forcing a locking engagement of said elongated support slide against one parallel sliding surface of said support pedestal and each said wedging means having a lever projection for manual urging of said locking engagement;

spring bias means urging locking engagement of said elongated support slide against said support pedestal;

a base support member to which said support pedestal is fixedly attached.

6. A mechanical support system for supporting and orienting work pieces therein comprising:

first and second T-clamps each having a long member and a cross member, said cross member having at least one serrated groove for receiving and fixedly clamping work pieces and having piercing means for further fixedly clamping said work pieces, said long member having at least one guide means extending parallel to a long edge along at least one surface thereof;

a clamp support member for cooperation with said T- square clamps comprising an elongated strip having at least one complementary guide means extending :parallel to a long edge along each of two opposite parallel sliding surfaces thereof for effecting a parallel sliding relationship with the guide means of said T-square clamps;

first and second wedging means mounted in operable proximity to said clamp support member for forcing a locking engagement of said first and second T-square clamps against the parallel sliding surfaces of said clamp support member and each of said first and second wedging means having a lever projection for manual urging of said locking engagement;

one of said rotatable support member and said fixed rotation support member having a plurality of rollers positioned in fixed radial relationship to the central axis thereof and the other of said rotatable support member and said fixed rotation support member having a plurality of complementary recesses in fixed radial relationship to the central axis thereof;

a rotatable coupling means coupling said rotatable support member to said fixed rotation support member and eifecting a load-bearing proximity relationship and axial alignment between said rotatable support member and said fixed rotation support member;

spring bias means urging the positioning of said rollers within said recesses when said rotatable support member and said fixed rotation support member are coupled in a load bearing relationship with axial alignment by which means rotation is prevented when spring bias is not forcibly overcome;

one of said rotatable elevation support member and said fixed elevation support member having a plurality of rollers positioned in fixed radial relationship to the central axis thereof and the other of said rotatable elevation support member and said fixed elevation support having a plurality of complementary recesses in fixed radial relationship to the central axis thereof;

at least one elongated support slide to which said fixed elevation support member is fixedly attached and having at least one guide means extending parallel to a long edge along at least one surface thereof;

a support pedestal for cooperation with said elongated support slide comprising an elongated strip having at least one complementary guide means extending parallel to a long edge along at least one of two parallel sliding surfaces thereof for effecting a parallel sliding relationship with the guide means of said elongated support slide;

at least one wedging means for each said elongated support slide mounted in operable proximity to said sup port pedestal for forcing a locking engagement of said elongated support slide against one parallel sliding surface of said support pedestal and each said wedging means having a lever projection for manual urging of said locking engagement; spring bias means urging locking engagement of said elongated support slide against said support pedestal; a pedal member mounted in operable proximity to said support pedestal; a transfer linkage connected between said pedal member and at least one of the said wedging means by which motion of said pedal member effects motion of said wedging means; base member comprising two foot support members to which said support pedestal is fixedly attached in an oblique relationship;

two rotatable feet attached to the foot support members of said base member and extensible to form an approximate equilateral triangle around a vertical projection of the center of gravity of all aforementioned members;

two compression spring biased pivot bolts effecting an abutted rotational relationship between said foot support members and said rotatable feet;

two locking means by which said foot support members may be fixedly coupled to said rotatable feet to prevent rotation in the extended position of said rotatable feet.

7. The mechanical support system of claim 6 wherein:

spring bias means urging locking engagements comprises an extension spring coupled between the lever attached to said wedging means and an adjacent static structure.

8. The mechanical support system of claim 6 wherein: wedging means comprises at least one rotatably mounted eccentric cam.

9. The mechanical support system of claim 6 wherein: spring bias means urging the positioning of said rollers within said recesses comprises a compression spring acting along central axis to which said rollers and said recesses are in fixed radial relationship.

10. The mechanical support system of claim 6 wherein: said complementary recesses each comprises a pair of raised durable bosses, i.e., the cross member of U-shaped staples so spaced that the raised bosses alone contact the circumference of said rollers.

References Cited UNITED STATES PATENTS 368,677 8/ 1887 Maxwell 248457 556,650 3/1896 Smith et al 248448 729,432 5/1903 Sidway et al. 248184 X 2,032,872 3/ 1936 Friedrichs 248449 FOREIGN PATENTS 2,055 2/ 1885 Great Britain.

ROY D. FRAZIER, Primary Examiner F. DOMOTOR, Assistant Examiner U.S. C1. X.R. 248452, 453, 457