US1974176A

US1974176A - Braking apparatus

Info

Publication number: US1974176A
Application number: US604917A
Authority: US
Inventors: Dick Burns
Original assignee: Wagner Electric Corp
Current assignee: Wagner Electric Corp
Priority date: 1932-04-13
Filing date: 1932-04-13
Publication date: 1934-09-18
Anticipated expiration: 1951-09-18

Description

Sept. 18, 1934. s. DICK BRAKING APPARATUS Fi1ed.Apri1 15, 1932 2 Sheets-Sheet 1 Inventor BU DICK Att'y.

Sept. 18, 1934. B. DICK BRAKING APPARATUS Filed.Apri1 1a, 1932 2 Sheets-Sheet 2 Inventor BURNS DICK Patented Sept. 18. 1934 PATENT OFFICE BRAKING APPARATUS Burns Dick, Ferguson, Mo., assignor'to Wagner Electric Corporation, St. Louis, Mo., a corporation of Delaware Application April 13, 1932, Serial No. 604,917 9 Claims. (c1. 188 -78) My invention relates to braking apparatus and more particularly to an improvement in band brakes of the type in which the reinforcing web has been divided intermediate the ends of the band into two portions which are pivoted together and free from the lining carrying flange adjacent the point of division, as described in the joint application of Steve Schnell and myself filed February 26, 1932, Serial No. 595,244.

The principal object of my invention is to pro- .duce an improved band brake of the type referred to that will require less pedal pressure to bring it into engagement with the drum and will also have less distortion of that part of the lining carrying flangethat is free from the reinforcing web. I

Another object of my invention is to provide improved means for pivotally connecting the two portions of the reinforcing web. I v

Other objects will become apparent from the following description of two embodiments of my invention taken in connection with the accompanying drawings in which Figure 1 is a side elevation of a brake assembly (the drum being brake band; Figure 2 is a cross sectional view on the line 2--2 of Figure 1; Figure 3 is a side elevation of a modified form of brake employing my improved'brake band; Figure 4 is a cross sectional view on the line 4-4 of Figure 3; and Figure 5 is a cross sectional view on the line 5-5 of Figure 3.

Referring to Figures 1 and 2, the numerall indicates the drum of the brake which is secured in the usual manner to 'the wheel of the vehicle and is enclosed on its open side by a backing plate or support 2 secured to some fixed part "of the vehicle. The brake shoe 3 is of the band type and is mounted within the drum and is adapted to have its ends expanded into engagement with "the drum by suitable means such as the hydraulic mechanism 4. The band is biased to off" position by the usual spring 5, its position clearance at each end being determined by the adjustable stops 6. s

The brake band 3 is of the T-s'ection type and comprises a lining receiving flange '7- and a reinforcing web 8. The web 8 is separated from 50 the flange at the central part of the band and degrees on each side of the center of the band, as

indicated at 9. The web 8 comprises two

spacedapart portions

10 and 11 formed by cutting out a shown in cross section) embodying my improved over an are extending approximately forty-five :adjaoent ends of the

web portions

10 and 11 are connected together by a pair of

links

12 and 13, the links .being pivoted at their ends to the web portions by suitable pins 14. This link connection between the web portions forms a very important part of my invention for by it the web 8 is provided with a double hinge joint at its center which allows each web portion to pivot about the link without aifecting the other portion or producing any distortion of the free portion of the flange 7.

When the hydraulic mechanism 4 is actuated, the force required .to bring the band ends into engagement with the drum will be only that necessary to overcome spring and to bend the flange 7 at its'central portion, since the inner ends of the web portions and 11 and the connecting link, are free to move inwardly relative to bend ng of the flange. The

links

12 and 13 are provided with coinciding

elongated openings

15 and 16 for the reception of an anchor pin 17 which is mounted in the backing plate 2. In order to provide additional bearing support for the anchor pin, the backing plate is provided with a reinforcing plate 18 which may be secured thereto by welding. The anchor pin carries an eccentric disc 19 positioned between the link 13 and the backing plate which cooperates with the flange '7 for adjusting the of! position clearance of the band at its center.- The external end of the anchor pin is headed and carries a spring 20 for holding the disc 19 in its adjusted position against the backing'plate. A washer 21 secured to the inner end of the anchor prevents. the links from slipping off the anchor pin. Two tension springs 22 and 23, connected to the backing plate and the web portion of the band as shown, tend to hold the center of the band in its 01f position.

When the hydraulic mechanism 4 is actuated,. the ends of the brake band are moved outwardly into engagement with the drum whose rotation may be assumed as in the direction of the arrow (Figure 1). The force to accomplish this, as previously stated, is that necessary to overcome the spring 5 and to bend the flange 7- at its center. Since the flange 7 is free from the web over its central portion, the high pressure that is usually built up in front of the anchor when the flange is not free from the web, is decreased due to the increased flexibility of the band. Also, the pivoting of the

web portions

10 and 11 about the flange and will not; therefore, restrain the I the links when the ends of the band are expanded,

flange 7 over the central portion and cause distortion of the freepart of the flange, as would be the case if the links were eliminated and the

web portions

10 and 11 pivoted directly together.

In the modification disclosed in Figures 3, 4 and 5, two

anchors

24 and 25, each comprising an adjustable pin 28 carried by the web and cooperating with an abutment plate 32 secured to the backing plate, one of said anchors being on one side of the link connection and the other anchor being on the opposite side. .The brake band 3 is identical with the band shown in.Figure 1 except that the

links

12 and 13 have been replaced by the

links

12 and 13 which are not provided with elongated openings. Since the two anchors are identical, one only will be described. A pair of disc members 26 and 2'7 are eccentrically and non-rotatively mounted on a bolt 28 extending through an opening of the web 8 of the band. The disc members are positioned upon opposite sides of the web and are clamped in place against the web by the washer 29 and the nut 30 on the end of the bolt. The end of the bolt 28 carrying the nut, extends through an over-size opening 31 in the backing plate to permit adjustment of the eccentric discs from the exterior of the brake and at the same time allow slight circumferential movement of the band with respect to the backing plate. The abutment for each anchor consists of a plate 32 riveted to the backing plate and provided with an extension adjacent each side of the web for cooperation with the eccentric disc members on the pin 28.

An adjustable eccentric cam member 33, secured to the inner end of a headed bolt 34 mounted on the backing plate, cooperates with the top edge of the links 12' and 13 to adjust the ofi position clearance of the central portion of the band, the links being held in contact with the cam by the

springs

22 and 23 when the band is in ofiP' position,

The action of the brake just described is the same as that of the form disclosed in Figure 1 1 adjusted from the exterior of the brake and when the oiT position clearance of the center of the band is adjusted by the eccentric cam 33, the anchor pins can also, be adjusted so they will contact with the abutment plates when the band ,7 is disengaged. This construction eliminates any possibility of a noise or click resulting from the anchor pin being carried into engagement with the abutment when the band is applied to the drum.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In braking apparatus, the combination of a drum, a flexible brake band adapted to have its ends expanded into engagement with the drum, said band comprising a continuous lining-carrying portion and a reinforcing web, said web comprising two portions having spaced apart ends intermediate the ends of the band and said ends being free of the lining-carrying portion, and means having pivotal relation with each web portion for connecting said portions. the free liningcarrying portion being unrestrained for free inward radi? movement by the ends of the web portions and their connecting means when the band is applied. p

2. In braking apparatus, the combination of a drum, a flexible brakeband adapted to have its ends expanded into engagement with the drum, 5 said band comprising a continuous lining carrying portion and a reinforcing web, the web being divided into two parts at a point intermediate the ends of the band and free from the lining carrying portion adjacent the point of division, 5 and a link pivotally connected to the end of each part for connecting the'parts of the web together, the free lining-carrying portion being unrestrained for inward radial movement by the ends of the web portions and the connecting link when the band is applied.

3. In braking apparatus, the combination of a drum, a flexible brake band adapted to have its ends expanded into engagement with the 'drum, said band comprising a continuous lining carrying portion and a reinforcing web, the web comprising two sections spaced apart intermediate the ends of the band and free from the lining carrying portion over a portion of th circumference of the band, and means connecting said 1 web sections and in pivotal relation with each section, said means being free from engagement with the lining carrying portion.

4. In braking apparatus, the combination of a drum, a flexible T-section brake band adapted to 1' have its ends expanded into engagement with the drum, the web of said band comprising two portions having spaced apart ends intermediate the ends of the band, said portions being integral with the flange except over the ends which arell spaced apart, and a link pivotally connected to each portion of the web.

5. In braking apparatus, the combination of a drum, a flexible brake band adapted to have its ends expanded into engagement with the drum, 11 said band comprising a continuous lining carrying portion and a reinforcing web and said web comprising two portions having spaced apart ends intermediate the ends of the band, said ends being free from the lining carrying portion, 11 a link pivotally connected to each portion, and an anchor for said band cooperating with said link, said anchor permitting free radial movement of the link and the free lining-carrying portion being unrestrained for inward radial movement by 1 the ends of the web portions and the connecting link when the band is applied.

6. In braking apparatus, the'combination of a drum, a flexible brake band adapted to have its 'ends expanded into engagement with the drum, 1

said band comprising a lining carrying portion and a reinforcing web and said web being divided into two parts at a point intermediate the ends of the band, a link connecting said web parts and in pivotal relation with each part, and an anchor 1 for said band located intermediate an end of the band and said link.

'7. In braking apparatus, the combination of a support, a drum, a flexible brake band adapted to have its ends expanded into engagement with] the drum, said band comprising a lining carrying portion and a reinforcing web and said web being divided into two parts at a point intermediate the ends of the band, means pivotally connected to each web part for joining the web parts together, and an anchor intermediate each end of the band and the connecting means, each anchor comprising an abutment carried by the support and an'adjustable pin carried by the web.

8. In braking apparatus, the combination of a l drum, a flexible brake band adapted to have its ends expanded into engagement with the drum, said band comprising a lining carrying portion and a reinforcing web and said web being divided into two parts at a point intermediate the ends of the band, means pivotally connected to each web part for joining the web parts together, and

an anchor intermediate each end of the band and the connecting means.

9. In braking apparatus, the combination of a drum, a flexible brake band adapted to have its ends expanded into engagement with the drum.

said band comprising a continuous lining carrying portion and a reinforcing web, said web being divided into two parts at a point intermediate the ends or the band and tree from the lining carrying portion adjacent said point of division, and anchor means for the band permitting the bending of the part of the lining carrying portion of the band which is free from the web to be unrestrained by said tree portion of the web during the expansion of the ends of the band to bring them into engagement with the BURNS DICK.