US2294815A - Floor surfacing machine - Google Patents

Description

P 1942- B. TOBIAS ETAL 2,294,815

FLOOR SURFACING MACHINE Filed March 21, 1939 2 Sheet sSheet 1 HUM mm w a Sept. 1, 1942. B. TOBIAS EFAL FLOOR SURFACING MACHINE Filed March 21, 1939 2 Sheets-Sheet 2 Patented Sept. 1, 1942 UNHTED ST TES ATET OFFIQE FLOOR SURFACING MACHINE Application March 21, 1939, Serial No. 263,138 In Great Britain March 21, 1938 2 Claims.

This invention relates to machines used for surfacing floors (by which term we also include decks and the like), comprising in essence a body, supporting driving means such as an electric motor and a surfacing drum which may be a sanding drum, or cutter block, or polishing drum.

A principal object of the invention is to enable such a machine to work close up to the skirting board; to this end the surfacing drum is arranged by its mode of support in such a manner that one end of its line of contact with the floor extends at least to the side of the machine.

The accompanying drawings illustrate an embodiment of the invention.

Figure 1 is a front View of the machine in section on the axis of the drum,

Figure 2 is a side view and Figure 3 is a plan view.

In the example the drum 23 is fast on a shaft 24 carried by bearings 25, 26 within a hollow cantilever 21. Since machines of the character in question are heavy there is a substantial bending moment at the junction of the cantiliver with the body and a substantial twisting moment between the section of the body to which the cantilever is joined and the part of the body to the rear of the drum. To provide adequate strength this section of the body is made as a double sided box section and as indicated in the drawings the cantilever, which can be ribbed, traverses the box section and is with the box section and the remainder of the body 30 cast in a single piece. One bearing 25 is preferably located as shown midway of the length of the drum with the drum boss 23 as close as possible. This minimises bending moment on the shaft; with even pressure on the drum there is then no bending moment on the section in the bearing and the maximum accidental value due to bumps on the floor can only have a lever arm of half the drum length. The other bearing 26 is placed as close as convenient to the driving member, again shown as a pulley 29.

The body must not of course extend beyond the outer end of the drum; indeed the drum may project a little beyond the side of the body. In view of the width of the box section above described this brings the mid point of the drum substantially to one side of the centre line of the body and the weight distribution will not be even. This can be corrected as shown in Figure 3 by employing a rear castor 3| set a suitable The proper distance will be such that the castor lies in a vertical plane, indicated by a chain line, which passes through the mid length of the drum and the centre of gravity 0. G. of the machine. be used. Two other wheels (32 in Figure 2) are preferably located close to the drum and adjustable spring means provided for varying the pressure on the drum in known manner. For instance part of the body carrying the drum may be hinged to the part supported by the wheels, or the front pair of wheels 32 may be carried on a rocker 33 pivoted at 34 to the body, an adjustable spring 35 acting thereon. Either mechanism may also be provided with known controls for lifting the drum off the floor for moving the machine from place to place or putting paper on the drum. Access for the latter purpose may be further facilitated by hinging distance to the other side of the centre line;

a cover 36 to the body which overhangs the drum during operation as shown in Figure 2. Such hinged cover may be provided with buffers 31. Other buffers may be provided on the side of the body to prevent actual contact of the drum end with the skirting board and the projection of all buffers may be adjustable. The rest of the machine including a suction device for collecting dust may be constructed on any suitable known lines. Also chain or gear drive can be employed.

What we claim is: I

1. In a fioor surfacing machine the combination of a body, a double sided box section rigid with said body on one side and at the front end thereof, a hollow transverse cantilever projecting from said box section towards the other side of said body, a shaft journalled within said cantilever, a surfacing drum fast to the end of said shaft at the free end of said cantilever, a driving member fast to the other end of said shaft, driving means on said body coupled to said driving member, and a single castor at the rear end of said body constituting with the drum the sole support for the machine when in operation under maximum out, said castor being placed towards the same side of said body as said box section so as to lie approximately in the vertical plane passing through the mid length of said drum and the centre of gravity of the machine.

2. A floor surfacing machine as set forth in claim 1 wherein said cantilever traverses said box section, and said body, box section and cantilever are constituted by an integral casting.

BENJAMIN TOBIAS. HAROLD KAI-IAN WARR-LANGTON.

Two castors suitably placed can also

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