US2246683A

US2246683A - Maintenance machine

Info

Publication number: US2246683A
Application number: US320228A
Authority: US
Inventors: William E Holt
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-02-23
Filing date: 1940-02-23
Publication date: 1941-06-24
Anticipated expiration: 1958-06-24

Description

. June 24, 1941.

w. E. HOLT 2,246,683

MAINTENANCE MACHINE Filed Feb. 23, 1940 2 Sheets-Sheet 1 Fig. 2

BY r

j ATTORNEY.

June 24,1941. w. E. HOLT 2,246,683

MAINTENANCE MACHINE Filed Feb. 25, 1940 2 Sheets-Sheet 2 l O 17 3 m 38 i6 5 /4 35 47 16 W I I, 10

z w mam- 54 w 1 1 vW/w 1N VEN TOR.

WilliamE Holt A TTORNE Y.

Patented June 24, 1941 iJNITED PATENT QFFICE MAINTENANCE MACHINE .William E. Holt, Oakland, Calif.

Application February 23, 1940, Serial No. 320,228 4', olaiias. (01. 49)

My present invention relates to theconstruc tion and operation of maintenance machines for treating the surfaces of floors, rugs and" the like by scrubbing, polishing, sanding, grinding, or shampooing the same.

Such machines normally include an electric motor mounted on a base casting, within which' is mounted a rotary brush or disc depending on the desired operation to be performed. Machines of this type are mounted on a' pair oi supporting wheels which are adapted to be swung to an inoperative position when the machine is in actual use. M n

The main object of my invention isthe pro-1 vision of an improved constructionof amaintenance machine of the type described which is particularly characterized by a silent, low cost and efficient speed reduction system between the electric motor and rotary brush of disc. A further and more specific objectfis the provision of a belt and pulley speed reduction system for a machine of the type described which affords the desired speed reduction while" permitting a coaxial arrangement of the electric motor and rotary brush and which can be readily mounted in the base casting of themachine. A further specific object is an improved wheel mounting and arrangement for a machine of the type described.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to andiorming a part of this specification. For a better understanding of the invention; its operatin advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described apreferred embodiment of my invention.

Of the drawings: I r

Fig. 1 is a side elevation of a floor maintenance machine constructed in accordance with my in vention; v Fig. 2 is a bottom view of the body of the machine shown in Fig. 1; p i

Fig. 3 is an enlarged elevation, mainly in section, of the base casting and associated partsj and v Fig. 4 is an enlarged view, partly in section, similar to Fig. 2, with some of the parts removed.

In the maintenance machine illustrated; the base casting or housing H! has a plate section I I or fiat circular shape over most of its area and extended at its rear end to form a smaller curved section merging into the front circular section.

An electric motor and housing iii are concentrically arranged relative to and mounted on the front circular section of the base casting with the motor shaft I4 vertically arranged and projecting downwardly through an opening l5 in the base casting. The motor housing is secured in its described position on the base casting by screws i6.

' The smaller rear end of the base casting plate It has a recessed boss I! in which is detachably mounted a sleeve I8 for receiving the lower end of an inclined handle pipe 19. At its upper end the pipe [9 has a switch box 20 and a pair of handle grips 2|. At a lower point on the pipe I9 is secured a cord hook 22 which serves as a support for an electric cable 23 adapted to connect the switch box 20 to an electric outlet. Aconductor 24 extends down through the pipe H) from the switch box to the motor, a thermostatically-operated cut-out switch 25 being interposed if'desired to prevent overheating of the motor.

' The base casting has a depending peripheral flange or skirt 26 extending entirely around the plate section II and of sufiicient height to conceal the speed reduction mechanism hereinafter described. A rubber bumper strip 21 extends around the circular part of the flange 2B and is held inposition by a wire 28 detachably secured to the flange 26. The portions of the flangeZGat opposite sides of the rear end of the base casting are thickened, as shown in Fig. 4, to form short side sections 30 with straight outer sides parallel to the longitudinal axis of the base casting. The thickened side sections 39 serve to support a pair of wheels 32, a cap screw 33 being mounted in each side section and having an outer unthreaded portion forming an axle for the corresponding wheel. The wheels 32 are so arranged on the base casting and proportioned in such a manner that they are above the floor level when the machine is in actual operation, but capable of forming a wheeled support when the machine is tilted back on the wheels. The direct support and described arrangement of the wheels on the base casting eliminates any necessity for manually shifting wheel supporting parts when the machine is put in or out of operation."

Maintenance machines of the type described have a large field of use in hospitals and other places where a minimum amount of noise is essential. The electric motor preferably used in such machines is of a low horsepower high speed type, such as /4-% H. P., 1475 R. P. M. The

desired brush speed is in the range 160-185 R. P. M. Reduction gear units have been mainly used heretofore between the motor and brush shaft, but are objectionable because of their relatively high cost, inaccessability, and noisy operation.

In the machine illustrated the desired speed reduction between the motor and brush is effectively obtained by a belt and pulley system housed in the base casting and consisting of a small pulley wheel 35 mounted on the lower end of the motor shaft it slightly below the lever of the plate section II. The pulley 35 drives a large rear pulley 36 mounted on a vertical jack shaft 3'! through a belt 39. The jack shaft 31 is rotatably supported in a bearing 38 in the bass I! of the base casting. The shaft 31 is eccentrically mounted in the bearing 38 as indicated in Figs. 3 and 4 and the bearing can be turned in the boss ll through a wing extension 38 to vary the position of the jack shaft longitudinally of the machine and thus control the tightness of the

belts

39 and 42. As shown, the shafts l4 and 31 have their axes intersecting the longitudinal center line of the base casting, providing a balanced arrangement. The pulley wheel 35 forms the upper part of a double pulley carried by the shaft 31, the smaller and lower pulley thereof having a drive connection through a belt 52 with a large front pulley 43 carried by an implement shaft 44 below and in axial alignment with the motor shaft M. The upper belt and pulleys form the first stage of speed reduction, while the lower belt and pulleys form the second stage.

The shaft 44 is mounted in a suitable bearing 45 in a flanged bearing casing 46 supported from the plate section of the base casting by means of set screws 4'! securing the casing 46 to a group of spaced bosses 48 depending from the underside of the plate section II. The bosses 48 are arranged to avoid interference with the belt 39, as indicated in Fig. 4, and extend downwardly sufficiently to provide clearance between the bottom of the motor shaft and the top of the shaft M. The hub of the pulley 43 is extended downwardly and a brush holder 59 secured to the bottom thereof by screws The brush holder has symmetrically spaced peripheral lugs 52 which are adapted to register with corresponding slots in a plate 53 and interlock with cam surfaces on the plate to hold the same in position. The plate 53 forms the upper part of a suitable rotary implement, such as the scrubbing brush 54 illustrated, for giving a floor or other surface the desired treatment. As shown the working side of the brush 54 is below the level of the wheels 32, so that the Wheels 32 need no adjustment to avoid contact with the floor when the brush is in operation.

The operation of the machine will be apparent from the foregoing description. The machine is moved to any desired location by tilting the same rearwardly until the supporting wheels are in contact with the floor and the brush is free. At the desired place, the motor is switched on and the power transmitted through the two stage belt and pulley system to the brush shaft 44 and brush 54. All of the rotary parts rotate in the same direction about axes symmetrically arranged relative to the base casting. The interlocking parts of the brush and brush holder are arranged so that the direction of rotation of the brush will maintain the same interlocked.

The machine can be readily assembled with only one reaming operation and six drilled and tapped holes required in the base casting. The speed reduction parts are especially simple and cheap, and practically noiseless in operation. Repairs and renewals of these parts can be quickly made by unskilled labor due to their simple construction and accessability.

While in accordance with the provisions of the statutes I have illustrated and described the best form of the invention now known to me, those skilled in the art will understand that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by my claims, and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

Iclaim:

1. A floor maintenance machine comprising a horizontally arranged base housing, an electric motor mounted on said housing with its shaft vertically arranged and extending downwardly through said housing, a vertical implement shaft positioned below said motor shaft, a speed reduction system connecting said motor and implement shafts and comprising a rotatable bearing mounted in said housing, a vertical jack shaft eccentrically journaled in said bearing, a belt and pulley drive connection between said motor shaft and said jack shaft, a second belt and pulley drive connection between said jack shaft and said implement shaft, an implement holder mounted on said implement shaft within said housing, and a rotary implement detachably mounted on said holder.

2. A floor maintenance machine comprising a horizontally arranged symmetrically shaped base housing, an electric motor symmetrically arranged relative to and mounted on the front portion of said housing with its shaft vertically arranged and extending downwardly through said housing, a vertical implement shaft positioned below and in axial alignment with said motor shaft, a speed reduction system connecting said motor and implement shafts and comprising a rotatable bearing mounted in the rear portion of said housing, a vertical jack shaft eccentrically journaled in said bearing, a belt and pulley drive connection between said motor shaft and said jack shaft, a second belt and pulley drive connection between said jack shaft and said implement shaft, an implement holder mounted on said implement shaft, and a rotary implement detachably mounted on said holder.

3. A floor maintenance machine comprising a horizontally arranged base housing, an electric motor mounted on the front portion of said housing with its shaft vertically arranged and extending downwardly through said housing, spaced depending bosses on said housing around said motor shaft, a bearing carried by said bosses, a vertical implement shaft mounted in said bearing below and in axial alignment with said motor shaft, a speed reduction system connecting said motor and implement shafts and comprising a vertical jack shaft rotatably mounted in the rear portion of said base housing, a belt and pulley drive connection between said motor shaft and said jack shaft, a second belt and pulley drive connection between said jack shaft and said implement shaft, and a rotary implement mounted on said implement shaft.

4. A floor maintenance machine comprising a horizontally arranged base housing having a symcomprising a vertical bearing mounted in the rear portion of said housing, a vertical jack shaft journaled in said vertical bearing, a belt and pulley drive connection between said motor shaft and said jack shaft, a second belt and pulley drive connection between said jack shaft and said implement shaft, an implement holder holder mounted on said implement shaft, and a r0- tary implement detachably mounted on said 10 holder.

' WILLIAM E. HOLT.