US3422576A - Belt sander or grinder - Google Patents

Description

Jan. 21, 1969 HUBBLE 3,422,576

BELT SANDER 0R GRINDER Filed March 19, 1965 i 8 m? mwfiw WH MA Am United States Patent 3,422,576 BELT SANDER OR GRINDER Ira L. Hubble, Box 9681, Birmingham, Ala. 35215 Filed Mar. 19, 1965, Ser. N 0. 441,073 US. "Cl. 51148 1 Claim Int. Cl. B24b 23/06; B24b 21/00; F16h 7/08 ABSTRACT OF THE DISCLOSURE A self-contained, portable, light-weight belt sander or grinder in which the entire apparatus is mounted on and supported from the motor itself and having means to maintain the belt in tension, which means also permits ready changing of the belt when necessary.

This invention relates to an improved, lightweight, portable belt sander or grinder and contemplates such apparatus which is essentially adapted for grinding or sharpening small tools and the like.

An object of my invention is to provide an inexpensive, portable, lightweight belt sander or grinder in which the motor for driving the belt forms the base or support for the entire device.

An object of my invention is to provide a sander or grinder of the character designated in which behind the belt, in the work area thereof, is provided a back-up member so that when the work piece is pressed against the belt, the belt is suitably backed up, thus giving a firm, accurate grinding surface.

Another object is to provide a sander or grinder of the character designated in which the upper or idler pulley is supported from a standard by means of a bellcrank or the like and in which the belt is held taut by means of a spring having one end anchored on a lever extending from the =bellcrank and the other end anchored to the standard.

Apparatus illustrating features of my invention and forming a part of this application is shown in the accompanying drawings in which:

FIG. 1 is a side elevational view;

FIG. 2 is an enlarged detail side elevational view viewed from the opposite side of FIG. 1;

FIG. 3 is an enlarged fragmentary front elevational view taken from the side toward which the work is applied to the belt; and,

FIG. 4 is a detail sectional view taken generally along line 4-4 of FIG. 2.

Referring now to the drawings for a better understanding of my invention I illustrate the same as embodying a small fractional horsepower motor indicated generally by the numeral 10. As customary, the motor embodies a base 11 and an output shaft 12.

Secured to an end of the motor is a bracket 13. Secured to the bracket and projecting upwardly, laterally removed from a vertical plane within which is included the output shaft 12, is a standard 14.

At the top of the standard is a horizontally disposed bearing 16. Passing through the bearing 16 is a pin 17. Fast on one end of the pin 17 is an arm 18 and fast on the other end is an arm 19.

Mounted in the forwardly extending portion of the arm 18 is a bearing pin 21 for rotatably supporting an idler pulley 22. It will be seen that the pin 21 is also horizonta1 ly disposed and is included within the vertical plane which also includes the output shaft 12. Thus, pulley 22 and a lower, driven pulley 23 fast on the shaft 12 are in alignment. A flexible sanding or grinding belt 24 passes over the pulleys.

Patented Jan. 21, 1969 The belt is held taut by means of a spring 26 having one end secured at 28 to the standard and the other end secured at 29 to the lower end of the arm 19. The pulleys are crowned as at 30, thus to hold the belt in alignment while the machine is operating.

Projecting forwardly from the standard 14 is a platelike member 31. On the forward end of the plate member 31 is a vertically directed back-up member or platen 32 which is adapted to back up the belt in the area where the work piece is to be applied thereto. The member 31 may be secured to the standard by means of a screw or the like 33 and the end of the screw 33 may project to provide the attaching point 28 for the spring 26.

In view of the foregoing the method of constructing and using my improved sander together with the advantages thereof "may now be explained and understood. With the device constructed as shown it will be apparent that the motor 10 and its base 11 support the entire superstructure. With the belt 24 trained over the pulleys and with the motor in operation it will be apparent that a work piece may be pressed against the grinding surface of the belt 24 in the area of the back up or support plate 32. Further, when it is desired to change belts it is only necessary to pull upwardly, as viewed in FIG. 2, on the lower end of the arm 19, thereby pivoting the arm 18 and hence the idler pulley 22 downwardly, thus to loosen the belt whereupon the belt may be slipped off the pulleys and a new one installed.

In view of the foregoing it will be apparent that I have invented an improved, lightweight and portable sander or grinder which is entirely supported from the motor which operates the same. My invention thus serves as an adjunct to heavy duty grinding equipment necessary in shops and the like for maintaining tools. Since the motor itself suports the apparatus it is quite portable and may be taken immediately to the job where needed. In view of the mounting of the upper pulley as shown, the changing of the belts requires but a few seconds.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefor, that only such limitations shall be placed thereupon as are specifically set forth in the appended claim.

What I claim is:

1. In a portable belt grinder,

(a) an electric motor embodying a housing, base and output shaft,

(b) a vertically upstanding standard rigidly secured to the housing and laterally of .a vertical plane within which is included the longitudinal axis of the output shaft of the motor,

(c) a first horizontally disposed bearing on the upper end of the standard,

(d) a pin rotatable in the first bearing,

(e) an arm fixed at one end to the pin and having a second horizontally disposed bearing at its opposite end, said second bearing having a longitudinal axis coincident with said vertical plane,

(f) a belt pulley rotatable in said second bearing,

(g) a belt pulley fixed to the output shaft of the motor,

(h) an endless, flexible grinding belt passing over the pulleys,

(i) spring means urging the pulley on said arm away from the pulley on the output shaft, thereby to maintain the belt tight, and

(j) a platen having a flat surface for the belt carried by the standard and against which the rear surface of the belt is pressed when a work piece is held 3 4 against the front working surface of the belt out- 2,780,033 2/1957 Albright 51-148 X wardly of the platen. 3,127,712 4/1964 Krogen 51148 References Cited LESTER M. SWINGLE, Primary Examiner.

UNITED STATES PATENTS 5 D. G. KELLY, Assistant Examiner.

2,313,254 3/1943 Mead 5l148 2,431,795 12/1947 Elmes s1 141

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