US2633940A - Brake wear take-up - Google Patents

Description

April 7, 53 G. w. OLSON 2,633,940

BRAkE WEAR TAKE-UP Filed March 8, 1948 2 SHEETS--SHEET l Qwuwwbo o GEORGE W. OLSON April 7, 1953 G. w. oLsoN BRAKE WEAR TAKE-UP 2 SHEETS-SHEET 2 Filed March 8, 1948 GEORGE W. OLSON be mounted on a corresponding timber on the wall or ceiling as may be required. In addition, and particularly for some jobs, the hoist has a bracket Welded to the mounting plate 34 and having a hook 4| and stiffening webs 42. A bolt 43 passes through the bracket and engages a clamp plate 44. The bracket may be hooked over an overhead beam (Fig. 1) and the clamp plate 44 pulled tight by the bolt 43 to solidly anchor the hoist in this position as will be readily understood.

To stop the rotation of the spool whenever required, and to hold the load, I provide a brake mechanism which will now be described. Referring particularly to Figs. 4-6, this mechanism is seen to include a brake drum 45' having a circular flange 47 and this drum is set into one end of the spool l9 through circular openings 48 in the spool end and the sprocket ring 2'! and welded in place to rotate with the spool. Positioned inside the drum are two conventionally brake surfaced brake shoes 49 and 50 of arcuate shape and at two adjacent ends these shoes are oscil-' latably mounted by being screwed upon anchor screws 5! and 52 respectively. These screws 5! and 52 extend out loosely through openings 53 in the adjacent end plate I4 and secured on the screws are collars 54 and 55 having reduced neck portions 56 (Fig. 5) also loosely fitting said openings 53. Set screws 5! are used to secure the collars '54 and 55 upon the respective anchor screws 5! and 52. Outwardly of the end plate I4 the collars 54 and 55 are cam shaped (Fig; 4), having flats 58 on adjacent surfaces, and positioned between these flats, in contact therewith, is a screw 59 by which a channel shaped lock clip or clamp is secured in place, with its edges bearing on the collars.

The opposite ends of the brake shoes 49 and 59 swing together or apart about the pivot connections with the anchor screws 5! and 52 and for adjusting the shoes in this manner, I provide an actuating cam 5! which is positioned between the shoe ends. A retractile coil spring 52 connects the shoes to normally pull them together and hold their ends in engagement with the cam 5|. The cam is ailixed to the inner end of a short shaft 63 journaled through a bearing 54 and provided, outside the end plate M, with a It will be readily understood that hand lever 55. by moving the hand lever 65 the-cam 6| may be rocked to spread the adjacent ends of the brake shoes 49 and 50 so that they will frictionally engage the brake drum and hold the spool l9 whereas opposite movement of the handle will allow the spring 52 to contract the shoes pulling them out of such braking engagement with the drum.

The bearing 64 is formed at the end of an adjusting slide 56 extending along the outer side of the end plate !4 and having one end 51 bent over and spaced from the adjacent edge of the frame leg I I. A cap screw 68 is placed through this end 61 and screwed into the leg ll so that the slide 66 maybe adjusted toward and away from the axis of the spool shaft 20. The bearing 64 passes inwardly through a slot 59 in the end plate M to permit such adjustments, while a lock screw I0 is passed through a slot H in the slide and screwed into the end plate 20 that the slide may be firmly secured in any adjusted position.

This adjustment of the slide 56 permits the shoes 49 and 50. The cam 6| is tapered, being widest at its outer side as seen in Fig. 6, and such adjustment of the cam by the slide is utilized to take up wear on the shoes and drum. In other words, as wear occurs the cam 5| may be moved inwardly, by adjusting the screw 68 and then tightening the lock screw 10, to spread the shoes at this end and compensate for such wear.

It is to maintain even bearing or braking surfaces around the shoes as the wear occurs that I have provided the mounting previously described for the anchored ends of the shoes. Normally the anchor screws 5| and 52 and collars 54 and 55 are held tightly in position by the clip 50 but by loosening this clip the collars may be turned slightly and as they are so turned their flats 58 engaging the screw 59 will force the collars apart to correspondingly spread these ends of the brake shoes and compensatingly adjust them for wear as the cam 6! is moved inwardly for the same purpose. The clip may, of course, be retightened to hold each adjustment as made.

The useful life .of the brake will obviously be greatly extendedby these adjustments, and the simplicity with which they may be carried out even with only pliers for tools, is of great importance to my hoist since, by its very nature, it is in many cases subject to abuse and misuse by unskilled and careless workmen. It will be further noted in this connection that while the frame assembly is of welded construction throughout for simplicity and durability, all parts subject to wear are mounted by screws and the like so that they may be readily replaced when worn.

It is understood that suitable modifications may be made in the structure as disclosed, provided suchv modifications vcome within the spirit and scope of the appended claims. Having now therefore fully illustrated and described my invention, what I claimvto be new and desire to protect by Letters Patent is:

1. For a hoist spool, a brake mechanism comprising a brake drum carried by the spool, a pair of. arcuate brake shoes cooperating with the drum, cam means pivotally supporting two adjacent ends of the shoes so that their other ends may swing apart into engagement with the drum. said cam means being also operative to adjust the spaces between .the pivoted ends of the whereby such adjustment thereof will adjust the spread between the cam actuated ends of the shoe.

2. For a hoist having a frame and a spool, a brake mechanism of the character-described.

comprising a brake drum secured to the spool,"

a pair of arcuate brake shoes cooperating with the drum, anchor screws pivotally mounting two adjacent ends of the shoes on the frame, cams supporting said anchor screws, means for adjusting said cams to adjust these ends of the shoes with respect to the drum, an actuating cam positioned between the opposite ends of the shoes and said actuating cam being inwardly tapered toward the axis of the drum whereby oscillation of this cam will spread these ends of the shoes, means for moving the actuating cam, and means supporting the actuating cam on the frame for movements radially of the drum to adjust the the drum. r

3. For B; hoist having a frame and a spool, a brake mechanism of the character described, comprising a brake drum secured to the spool, a pair of arcuate brake shoes cooperating with the drum, anchor screws pivotally mounting two adjacent ends of the shoes on the frame, cams supporting said anchor screws, means for adjusting said cams to adjust these ends of the shoes with respect to the drum. an actuating cam positioned between the opposite ends of the shoes and said actuating cam being inwardly tapered toward the axis of the drum whereby oscillation of this cam will spread these ends of the shoes, means for moving the actuating cam, means supporting the actuating cam on the frame for movements radially of .the drum to adjust the adjacent ends of the shoes with respect to the drum, a clamp screw on the frame between the cams carrying the anchor screws and operatively engaging said cams, and a clamp secured by the clamp screw over the cams.

GEORGE W. OLSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,113,951 Box Oct. 20, 1914 1,551,551 French Sept. 1, 1925 1,551,587 Sherbondy Sept. 1, 1925 1,821,338 Garson Sept. 1, 1931 1,860,959 Schnell May 31, 1932 1,933,671 Keese Nov. 7, 1933 2,296,184 Riise Sept. 15, 1942 2,323,800 Curtiss July 6, 1943 2,411,038

Hetteen Nov. 12, 1946

Images