US 3222706 A
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Description (OCR text may contain errors)
Dec. 14-, 1965 KAAR ETAL 3,222,706;
SWEEPING MACHINE Filed April 12, 1962 5 Sheets-Sheet l I w W YNVENTORS KENNETH B. KAAR GUY E. CQONS, DECEASED BY,SYLVIA IRENE COONS, EXECUTRIX BY'OLSEN mo STEPHENSON ATTORNEYS Dec. 14, 1965 K. B. KAAR ETAL 3,222,706
SWEEPING MACHINE Filed April 12, 1962 5 Sheets-Sheet 2 E42. ZE=E INVENTORS KENNETH B. KAAR GUY E. COONS, DECEASED BY, SYLVIA IRENE COONS,EXECUTRIX OLSEN AND gjglgkl EgSON Dec. 14, 1965 K. B. KAAR ETAL 3,222,706
SWEEPING MACHINE Filed April 12, 1962 3 Sheets-Sheet 15 EJ; SE17 f T T T 235 20 J 8 I 25\222 /2,30 l
m T X INVENTORS KENNETH a. KAAR GUY E. COONS, DECEASED SYLVIA IRENE COONS, EXECUTRIX I30 BY OLSEN AND sTgiztlgbggm United States Patent SWEEPING MACHINE Kenneth B. Kaar, Lincoln, Nebia, and Guy E. Coons, de-
ceased, late of Lincoln, Nehru, by Sylvia Irene Coons, executrix, Lincoln, Nehru, assignors to Sweep-All Company, lino, Lincoln, Nehru, a corporation of Nebraska Filed Apr. 12, 1962, Ser. No. 187,136 2 Claims. (Cl. 15-340) The present invention relates to mobile sweeping apparatus adapted to be moved over a surface such as a street, a parking area, a sidewalk, an airfield runway, or a factory or similar floor, for removing coarse trash such as pieces of paper, wood, metal, etc, as well as fine dirt and sand and similar material.
Sweeping apparatus presently in common use is ineffective in picking up both coarse and fine material and is generally objectionable because of the clouds of dust and the like which are created by use of the apparatus. It is an object of this invention, therefore, to provide an im* proved sweeping machine which is operable to remove both fine dust and larger trash from a surface to be cleaned.
A further object of this invention is to provide sweeping apparatus which includes vacuum means for removing and collecting dirt and sand from the surface to be cleaned and impeller means which operates to remove larger trash from the surface.
Another object of this invention is to provide sweeper apparatus which includes an improved vacuum and dirt collection assembly that cooperates with a sweeper brush to insure cleaning of dirt from the surface being cleaned.
Still a further object of this invention is to provide a sweeping machine with .a rotatable brush and impeller assembly which provides for removal of trash from the surface being cleaned.
Another object of this invention is to provide a sweeping machine having separate collection receptacles for trash and dirt which are arranged so that the trash and dirt are readily removed therefrom.
Yet another object of this invention is to provide a sweeping machine which is readily movable from one location to another.
Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawing in which:
FIGURE 1 is a side elevational view of the sweeping machine of this invention;
FIGURE 2 is a foreshortened vertical sectional view of a portion of the machine of this invention, showing the trash collecting receptacle in condition for receiving trash;
FIGURE 3 is a vertical sectional view of the front end portion of the sweeping machine of this invention, showing the trash receiving receptacle in a position having the front end thereof open so that the trash therein is removed from the receptacle;
FIGURE 4 is a fragmentary sectional view of the rear wheel supporting structure in the sweeping machine of this invention, showing the wheel supporting structure in an upwardly moved position corresponding to a surface engaging position of the brush in the sweeper machine;
FIGURE 5 is a vertical sectional view of the wheel supporting structure, illustrated similarly to FIG. 4, showing the structure in a downwardly moved position corresponding to a raised position of the brush in the sweeping machine of this invention;
FIGURE 6 is a rear elevational view of the sweeping machine of this invention; and
FIGURE 7 is a diagrammatic view of the hydraulic system in the sweeper machine of this invention.
With reference to the drawing, the sweeping machine of this invention, indicated generally at 10, is illustrated in FIGS. 1, 2 and 6 as including a main frame 12, which is formed of upright side frame members 14 rigidly connected by a top frame unit 16, a pair of front wheels 18, and a pair of rear wheels 20. An elongated brush 22 extends transversely of the main frame 12 between the frame side members 14 and is fixed on a shaft 24 which is rotatably supported on the frame side members 14. An impeller 26 includes a shaft 28 which is rotatably supported on the main frame side members 14 at a position forwardly of the brush 22. The impeller 26 also includes flexible vanes or blades 30 which are secured to the shaft 28 by .angle members 32.
A trash receiving receptacle 34 is positioned between the main frame side members 14 and supported on the main frame 12 at a position forwardly of the impeller 26. The receptacle 34 includes a bottom Wall 36 and has an open rear side 38. The front side 40 of the receptacle 34 is closable by a front door 42 which is secured to a trash removal or pusher member 44 which is positioned at the top of the receptacle 34 in the closed position of the door 42 illustrated in FIG. 2. The front door 42 and the pusher member 44 are mounted on a frame assembly 46 which is pivotally supported on a shaft 48 carried by frame members 50 mounted on the main frame 12. A pair of hydraulic cylinder assemblies 52, mounted on the main frame 12 at positions outwardly of the side frame members 14 are connected by pivot pins 54 to the frame assembly 46 and are operable on extension, to rotate the front door 42 and the pusher member 44 substantially 90 from their positions shown in FIG. 2 to their positions shown in FIG. 3 in which the front door 42 is substantially horizontal and projects forwardly from the sweeper machine 10. During such movement, the pusher member 44 is moved forwardly through the receptacle 34 so that a flexible lip 56 on the pusher member 44 moves forwardly along the receptacle bottom wall 36 so as to push any trash in the receptacle 34 forwardly there of and out the front end 40 thereof.
A housing 58, having a curved top wall 60, side walls 62, and upright end walls 64 and 66, is supported on the main frame top unit 16. An upright hollow duct 68 communicates at its top end 70 with the interior of the housing 58 and has its bottom end 72 positioned adjacent a deflector 74 which is mounted on the main frame 12 and positioned adjacent the periphery of the brush 22 adjacent the top and front sides of the brush. The deflector 74 is connected to a curved wall or shield unit 76 positioned closely adjacent the top and rear sides of the brush 22. The wall member 76 cooperates with the main frame 12 to form a downwardly opening chamber 78 on the main frame 12 which opens downwardly and communicates with the duct 68 for a purpose to appear presently. As shown in FIG. 2, the brush 22 is positioned in the chamber 78.
A hollow filter sleeve 80 is mounted on a framework 82 positioned in the housing 58. The sleeve 80 is constructed of filter paper, or other similar disposable material, and the framework 82 consists of cross frame members 84 secured to a hollow hub 86 and having wire or the like 85 mounted thereon so as to form an open body of a shape corresponding to the desired shape of the filter sleeve 80. As shown in FIG. 2, the sleeve 80 is of generally egg shape for a purpose to appear presently. One end of the framework 82 carries a cover plate 88 (FIG. 1) which is of a shape to cover an opening 90 in the housing end wall 66. In mounting the filter sleeve 80 in the housing 58, the hub 86 is supported on a rod 92 carried by the housing end wall 64 and the sleeve 80 is moved toward the end wall 64 until the adjacent end of the sleeve 80 engages the end wall 64. In this position of the sleeve 80, the cover plate 88 closes the housing opening 90.
A flexible hose 94, connected to the end cover plate 88 so as to communicate with the interior of the hollow filter sleeve 80, is connected to the inlet 96 for a suction fan or blower unit 98 having an exhaust pipe 100. The unit 98 is mounted on the top side of the main frame 12 adjacent the rear end thereof as shown in FIG. 1.
It can thus be seen that on operation of the blower unit 98, air is drawn into the housing 58 from the chamber 78 through the duct 68. This air travels through the filter sleeve 80 and the flexible hose 94 to the blower unit 98, so that any dirt in the air drawn out of the chamber 78 is filtered out of the air and deposited on the sleeve 80. A dirt collecting pan 102 projects into the housing 58 and is slidably supported on the main frame top unit 16 at a position below the filter sleeve 80 so that dirt on the sleeve 80 will drop downwardly onto the pan 102 which can then be removed to remove the dirt from the housing 58. The egg-shape of the filter sleeve 80, so that its upper end is of reduced size, facilitates the dropping of dirt therefrom into the pan 102, and if desired, additional structure, such as a vibrator (not shown) may be provided for agitating the sleeve 80 so as to further insure the removal of dirt therefrom for deposit in the pan 102. To prevent the suction of trash out of the receptacle 34 through the open rear side 38 thereof, flexible tubes 104, only one of which is shown, are connected to and extended between the housing 58 and the pusher member 44 so as to provide for substantial equilization of air pressures in all parts of the receptacle 34.
An engine 106 is mounted on the main frame 12 at a position to one side of the blower unit 98 (FIG. 6) and has a drive shaft 108 which is belt-connected to a pair of pumps 110 and 112 which are also mounted on the main frame 12. As shown in FIG. 6, a belt and pulley assembly 114 extends between a hydraulic motor 116 driven by the pump 110 and the blower 98 for driving the blower 98.
The pump 112 supplies fluid to a sweeper propelling motor 118 which is mounted on a frame member 120 and connected by chains 122 to the rear wheels 20 for driving the machine 10. The rear wheels 20 are mounted on an axle 124 which is rotatably supported on a frame member 120 which is in turn supported at its rear end on a pivot 126 carried by the main frame 12. The front end of the frame member 120 is connected by a pin 128 to the lower end of the piston rod 130 for a hydraulic cylinder assembly 132 which is pivotally supported at its upper end on a pin 134 carried by the main frame 12. As shown in FIG. 5, when the cylinder assembly 132 is supplied with fluid so as to move the piston rod 130 downwardly, the frame member 120 is swung downwardly and rearwardly about the pivot 126 to thereby move the rear end of the main frame 12 upwardly. Such movement of the main frame 12 effects a lifting of the brush 22 to a position above the ground surface so that the machine v can be more readily transported.
The hydraulic control circuit for the machine 10 is shown in FIG. 7. As shown therein, pumps 110 and 112 are driven by the motor 106 and are connected on their inlet sides by conduits 136 and 138, respectively, to a reservoir or tank 140. The tank 140 is shown in FIGS. 1 and 2 mounted on the main frame 12 at a position between the housing 58 and the blower 98. The conduits, such as the conduits 136 and 138, which connect the hydraulic components in the control circuit shown in FIG. 7, are not shown in FIGS. 1-6, inclusive, for purposes of clarity. As shown in FIG. 7, the hydraulic control circuit for the machine 10 consists of a sweeping circuit 142 having the pump therein, and a propulsion circuit 144 having the pump 112 therein, and the circuits are interconnected in a manner to be presently described. In the sweeping circuit 142, the pump 110 supplies fluid to a conduit 146 which has a pressure relief valve 148 therein and is connected to a manual two-position control valve 150.
In the position of the control valve 150 shown in FIG. 7, fluid from the conduit 146 flows through a by-pass passage 152 in the valve 150 and into a conduit 154 which connects to the propulsion circuit 144. In a second position of the valve 150, fluid from the conduit 146 travels through a passage 156 in the valve 150 into a conduit 158 which is connected to a second control valve 160 which is likewise movable between two positions. In the position of the control valve 160 shown in FIG. 7, fluid from the conduit 158 travels through a by-pass passage 162 in the valve 160 and flows into a conduit 164. In the second position of the valve 160, fluid from the line 158 travels through a valve passage 166 and flows into a conduit 168 which supplies fluid to a pair of speed control valves 170 and 172. The valve 170 is connected to a hydraulic motor 174, hereinafter referred to as the brush motor, which drives a sprocket 176 (FIG. 1). A chain 178 is trained about the sprocket 176, a sprocket 180 secured to the impeller shaft 28, an idler sprocket 182 mounted on one of the main frame side members 14, and a sprocket 184 secured to the shaft 24 for the brush 22. Thus, on a supply of fluid to the hydraulic motor 174, the brush 22 and the impeller 26 are rotated clockwise and counterclockwise, respectively, as viewed in FIG. 2. The speed control valve 172 is connected to the blower motor 116. In the second position of the valve member 160, a passage 186 therein connects a discharge conduit 188 for the motors 174 and 116 to the conduit 164 which is connected to a two-position valve 190. The valve 190 controls the supply of fluid to a pair of motors 192 and 194 which drive a pair of gutter sweepers 196 and 198 mounted on the main frame side members 14 so as to sweep areas to opposite sides of the machine 10 and direct the trash and dirt on opposite sides into the path of the impeller 26 and the brush 22. Each of the motors 192 and 194 is mounted on a bracket secured to a side frame member 14.
In the position of the valve 190 illustrated in FIG. 7, fluid from the conduit 164 flows through a valve passage 200, through the motors 192 and 194 and returns through a valve passage 202 for flow into a conduit 204. In the second position of the valve 190, a by-pass passage 206 in the valve connects the conduits 164 and 204. The conduit 204 supplies fluid to a three-position valve 208 which controls the supply of fluid to the hydraulic cylinder assemblies 52 which actuate the front door 42 and the pusher member 44 for the trash receptacle 34. Only one cylinder 52 is indicated diagrammatically in FIG. 7 but it is to be understood that the cylinders 52 are connected in parallel, in a well-known manner, so that they operate in unison. In the neutral position of the valve 208 shown in FIG. 7 the conduit 204 connects to a valve by-pass passage 210 so that fluid flows through the passage 210 into a conduit 212. In a second, or receptacle dumping position of the valve 208, fluid from the conduit 204 flows through a valve passage 214 into a conduit 215 connected to the cylinder assemblies 52 so as to extend the piston rods therefor, and fluid flows out of the cylinder assemblies 52 through a line 216 for flow through the valve passage 218 into the conduit 212. In the third position, or receptacle closing position of the valve 208, fluid from the conduit 204 flows through a valve passage 220 into the cylinder assemblies 52 so as to retract the piston rods and out of the cylinder assemblies through the line 215 for flow through a valve passage 222 into the conduit 212.
The conduit 212 is connected to a three-position control valve 224 which controls the supply of fluid to the brush lift cylinder assembly 132. In the neutral position of the valve 224 illustrated in FIG. 7, fluid flows through a valve by-pass passage 226 into a conduit 228 so that the cylinder assembly 132 is not actuated. In a second or brush lifting position of the valve 224, fluid from the conduit 212 flows through a valve passage 230 into a conduit 232 so as to supply fluid to the cylinder assembly 132 so as to extend the piston rod 130 to thereby lift the brush 22. Fluid flows out of the cylinder assembly 132 through a conduit 235 and a valve passage 234 into the conduit 228. In a third or brush lowering position of the valve 224, fluid from the conduit 212 flows through a valve passage 236 into the conduit 235 so as to retract the piston rod 130 and lower the brush 22. Fluid flows out of the cylinder assembly 132 through the line 232 and the valve passage 238 into the conduit 228. The conduit 228 connects to a conduit 240 having a filter 242 and a check valve 244 connected in parallel therein and connected to the tank 140 so as to return fluid theret0.
The propulsion circuit 144 has the pump 112 therein connected to a conduit 243 which has a pressure relief valve 245 therein and is connected to a manual speed control valve 246. The valve 246 has two outlet connections, one of which is connected to a conduit 248 which empties into the tank 140 and the other one of which is connected to a conduit 250 which is connected to a manual control valve 252. Adjustment of the manual control for the valve 246 regulates the proportion of fluid discharge from the valve 246 which flows, respectively, into the conduits 248 and 250.
In the neutral position of the valve 252 shown in FIG. 7, a valve by-pass passage 256 connects the conduit 250 with a conduit 254 connected to the return conduit 240. In a machine forward position of the valve 252, passages 258 and 260 therein connect conduits 262 and 264 connected to the machine propulsion motor 118 so as to drive the motor 118 in a direction to move the machine forwardly. In a machine reverse position of the valve 252, passages 266 and 268 therein are connected to the conduits 264 and 262, respectively, so as to provide for operation of the motor 118 to move the machine 10 in a reverse direction.
In the operation of the machine 10, the operator stands on a platform 270 (FIGS. 1 and 6) positioned at the rear end of the main frame 12. If desired, a seat may be provided on or adjacent the platform 270. The operator steers the machine 10 by manipulating a pivoted control rod 272 (FIG. 6) which is connected in a well known manner by a steering linkage assembly 274 to the machine front wheels 18. During transport of the machine 270, the manual valve 224 is first moved to the brush lifting position in which the valve passages 230 and 234 connect the conduit 212 with the conduit 232 and the conduit 228 with the conduit 235 so that the hydraulic cylinder assembly 132 is extended to lift the brush 22 to a position above the surface on which the ground wheels 18 and 20 are traveling. The valve 224 is then moved to its neutral position shown in FIG. 7 to maintain the brush in its upper position. The manual valve 252 is moved between forward and reverse positions depending on the direction in which the machine 10 is to be moved and the valve 246 is manipulated to provide the desired speed of the machine 10. During transport of the machine 10, the valve 150 is moved to the position shown in FIG. 7 to divert fluid from the sweeping circuit 142 to the propulsion circuit 144 to provide additional fluid for the circuit 144 and thereby make it possible to move the machine 10 at higher rates of speed.
When the machine 10 has been moved to the surface which it is desired to clean, the valve 224 is moved to the brush lowering position in which the valve passage 236 connects the conduits 212 and 235 and the valve passage 238 connects the conduits 228 and 232 to thereby effect a retraction of the hydraulic cylinder assembly 132 to its position shown in FIG. 4 in which position the brush 22 is engageable with the surface to be cleaned. The valve is moved to a position in which the valve passage 156 connects the conduits 146 and 158 so that the sweeping circuit 142 is operable and is disconnected from the propulsion circuit 144. The valve 160 is moved to a position in which the valve passage 166 connects the conduits 158 and 168 to provide for a supply of fluid to the blower motor 116 and the brush motor 174. During operation of the motor 116, the blower unit 98 operates to produce a suction in the duct 68 so that air is drawn out of the chamber 78 into the housing 58, through the filter sleeve 80 and the flexible hose 94 into the blower unit 98. Also, at such time the chain 178 is driven to provide for a rotation of the brush 22 in a clockwise direction as viewed in FIG. 2 and to provide for a rotation of the impeller 26 in a counterclockwise direction as viewed in FIG. 2. The valves 246 and 252 are then manipulated to provide for a forward movement of the machine 10 over the surface to be cleaned. During such movement, the impeller 26 contacts any large pieces of trash, such as discarded cigarette packages and boxes, pieces of wood, pieces of metal, etc., and throws each piece of trash upwardly and rearwardly toward the rotating brush 22. On contact with the brush 22, the trash thrown up by the impeller 26 is thrown by the brush 22 into the open rear end of the receptacle 34 so that it accumulates in the receptacle 34. The deflector 74 prevents any of the trash thrown up by the impeller 26 from being thrown over the top side of the brush 22.
The rotating brush 22 picks up fine particles of dirt and sand and this material on the brush 22 is drawn off the brush by the suction in the chamber 78 created by the upward flow of air in the conduit 68. In addition the lower end 72 of the duct 68 is located relative to the brush 22 such that the dirt and sand on the surface being cleaned is thrown upwardly by the brush 22 toward the lower end of the duct 68. Consequently, dust picked up by the brush 22 is mixed with the air being drawn upwardly in the conduit 68 so that the dust is carried upwardly into the housing 58 and accumulates on the filter sleeve 80. Accordingly, only filtered air travels out of the housing 58 through the flexible hose 94, and the dirt on the filter sleeve 80 falls off the sleeve into the dirt collection pan 102. The substantially egg-shape of the fil-ter sleeve 80 provides a filter sleeve having a top surface, from which it is more difficult to remove the dust, of minimum size. Consequently, the shape of the filter sleeve 80 contributes to the efficient discharge of dust therefrom into the pan 102. The hoses 104 between the housing 58 and the trash receptacle 34 provide for an equalization of pressures in the receptacle 34 to prevent trash from being drawn out of the receptacle 34 into the chamber 78. By virtue of the cooperative action of the impeller 26 and the brush 22, and the implementing action of the vacuum chamber 78, an efllcient and thorough cleaning of the surface to be cleaned is effected.
In the event gutters or areas close to building walls and the like are to be cleaned, the valve is moved to its position shown in FIG. 7 to provide for operation of the gutter sweepers 196 and 198 which are mounted on opposite sides of the main frame 12 so that they can move through a gutter or a surface adjacent a building wall without having to move the machine 10 dangerously close to the wall.
When the dust collection pan 102 becomes filled with dust, it is readily removed from the housing 58 by sliding it outwardly on the top frame unit 16. After dumping of its contents, the pan 102 is replaced. When the filter sleeve 80 becomes clogged with dust particles, it is readily removed and replaced by merely removing the supporting framework 82 from the housing 58. To remove trash from the receptacle 34, the operator moves the valve 208 from its neutral position shown in FIG. 7 to its lift position in which the valve passage 214 connects the conduit 204 with the hydraulic cylinder assemblies 52 so as to extend the piston rods in the assemblies 52. Extension of the piston rods provides for an upwardly pivotal movement of the supporting framework 46 so that the trash receptacle front door 42 is moved upwardly to its position shown in FIG. 3 and the trash pusher member 44 is swung in a clockwise direction about the pivot 48 from its position shown in FIG. 2 to its position shown in FIG. 3. The lip 56 on the pusher member 44 moves forwardly across the receptacle bottom wall 36 to push all the trash in the receptacle out the front end 40 thereof. The trash may be dumped either in a trash collection area or into another container which is used to transport the trash to a collection area.
From the above description it is seen that this invention provides a sweeping machine which, by virtue of the vacuum action of the machine 10 and the cooperative action of the impeller 26 and the brush 22, is operable to remove both fine dust and larger trash from a surface to be cleaned. By virtue of the replaceable filter sleeve 80, the vacuum system is readily maintained in an efficient condition. Furthermore, the contents of the machine 10 can readily be removed for dumping. By virtue of the arrangement of the circuits 142 and 144 shown in FIG. 7, the machine 10 may readily be transported at higher speeds to the desired point of use.
It will be understood that the sweeping machine which is herein disclosed and described is presented for purposes of explanation and illustration and is not intended to indicate limits of the invention, the scope of which is defined by the following claims.
What is claimed is:
1. In a sweeping machine having a main frame which has ground wheels providing for movement of said machine over a surface, means on said main frame forming a chamber intermediate the ends of said main frame, a brush rotatably mounted on said main frame and disposed in said chamber, suction means on said main frame disposed above said chamber and communicating therewith for removing dirt from said brush and said chamber, removable filter means operatively associated with said suction means for collecting dirt removed from said brush and chamber, means pivotally supporting at least one of the ground wheels on said main frame, power means on said main frame connected to said wheel supporting means for moving at least one of said whee-ls up and down to move said brush between a surface engaging position and a position spaced above said surface, an impeller rotatably mounted on said main frame at a position forwardly of said brush for impelling trash into the path of said brush, guard means mounted on said main frame and projecting into said chamber at a position adjacent the front and top sides of said brush for deflecting trash impelled toward the top side of said brush by said impeller, a trash collecting receptacle on said main frame having an open rear side disposed above said impeller and located so that trash impelled into the path of said brush is thrown into said receptacle through the open rear side thereof, said receptacle having a front door and a pusher member connected thereto which extends rearwardly from said front door, means pivotally mounting said door and pusher member for rotation about a substantially horizontal axis disposed above said receptacle, and means for rotating said door and pusher member in a direction to move said door away from the front end of said receptacle and move said pusher member forwardly through said receptacle to move trash therein out the front end thereof.
2. In a sweeping machine having a main frame provided with front and rear ground wheels, a brush rotatably mounted on said main frame, an impeller rotatably mounted on said main frame at a position forwardly of said brush for impelling trash into the path of said brush, first hydraulic motor means for driving said brush and said impeller, a trash receptacle on said main frame having an open end positioned so that trash impelled into the path of said brush is thrown by the brush into said receptacle through the open end thereof, a trash removal member mounted for movement through said receptacle so as to remove trash therefrom, second hydraulic motor means for moving said trash removal member, third hydraulic motor means for moving some of said ground wheels vertically relative to others of said ground wheels for raising and lowering said brush, fourth hydraulic motor means for driving said ground wheels, engine means on said main frame, first pump means arranged in a driven relation with said engine and connected in a first hydraulic circuit with said first, second and third motor means, second pump means arranged in a driven relation with said engine and connected in second hydraulic circuit with said fourth motor means, conduit means connecting said first and second circuits, and manually operable valve means in said conduit means operable in one position to direct fluid from said first pump means to said second circuit.
References Cited by the Examiner UNITED STATES PATENTS 574,850 1/ 1897 Carrier. 2,300,280 10/ 1942 Teager. 2,484,491 10/ 1949 Daugherty. 2,663,045 12/1953 Conway 15354 X 2,682,153 6/1954 Fink 280--43.23 X 2,739,340 3/1956 Blydenburgh et al. 15340 X 2,789,067 4/1957 Link 1583 X 2,833,116 5/1958 Rush. 2,913,744 11/1959 Gregersen 15340 X 3,087,179 4/1963 Talboys 1555 FOREIGN PATENTS 479,455 2/ 1938 Great Britain.
CHARLES A. WILLMUTH, Primary Examiner.
WALTER A. SCHEEL, Examiner.