AU619758B2 - An improved brake assembly - Google Patents

Description

9 9 94 9 .99,94 9 9. 9 9, *4 *9 4 99 1 99 4 4 99 99 ~9 S 9.

9999 9. 9

I

COMMONWEALTH OF AUSTRALIA Patents Act 1952 OTTh3RDKDWM WILALJIEAM YM3EIN-1i3]LW (Patent Application No. PI 4346) SPECIFICATION FOR THE INVENTION ENTITLED:- 9999 9 .9.9 99.9..

0 9 9 AN IMPROVED BRAKE ASSEMBLY"~ The following statement is a full description -to tbi~s Invention, including the best method of performing it known to me:- P ~D IIIYIII_,-LII-~l il liiNi_.rll .IC1~~ 2 This invention relates to an improved brake assembly.

This invention is particularly applicable to brakes for rider mowers but of course it is to be understood that it can be utilized in other applications as desired. For illustrative purposes however, this invention will now be described with reference to the application of the brake assembly to rider mowers.

Rider mowers are often operated on sloping ground and thus it is essential that there be provided suitable means S10 for holding the parked mower on a slope. For reasons of t t 4 44 economy, many rider mowers incorporate a brake in the drive train, operatively aherad of the tinal axle. In such installations the brake becomes inoperative if the drive train fails. Furthermore it may be necessary to provide a brake for general operation of the rider mower as well as for S parking. Accordingly, rider mowers are often fitted with a parking brake and a conventional brake which, in use, is operable to slow the vehicle.

Such rider mowers may be operated by unskilled persons and it has been found that parking brakes are often left engaged in use and thus made ineffective. This may lead to dangerous situations occurring, of which the operator may be unaware. Furthermore, the complexity of twin braking systems, that is one for paxking and one for normal driving, adds markedly to the cost of manufacture of a rider mower.

This invention aims to alleviate the abovementioned disadvantages and to provide a brake assembly which will be reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent.

With the foregoing and other objects in view, this invention in one aspects resides broadly in an external contracting brake assembly including:a rotary member to be braked; a pair of opposed braking shoes pivotally connected together about a fixed pivot assembly for pivotal movement between an engaged attitude engaged with said rotary member and disengaged attitude operatively spaced from said rotary member; supporting members on each said shoe remote from said fixed pivot assembly and arranged in spaced apart relationship whereby 15 they may be moved together to pivot said braking shoes to said ••Bee: engaged attitude; a manual actuating lever extending across a face of one supporting member remote from the other supporting member and having an abutment engageable with said face, and o0 20 connecting means connecting said other supporting member to said lever at a position spaced from said abutment whereby said lever may be pivoted about said abutment to an applied position at which said braking shoes are disposed in said engaged attitude.

25 Preferably the actuating lever in the locked position is so arranged as to obstruct operation of the controls for said rotary member so as to minimize the possibility of the latter being operated without the actuating lever being released from SSsaid locked position.

30 The braking members may be external shoes of a contracting drum brake or they may be internal shoes of an expanding drum o brake. Alternatively the braking member may be pads of a disa brake assembly or they may be a single spring member which may c,,ntract about a rotating drum.

I Preferably the lever is associated with suitable holding means tnd wherein said holding means in one embodiment includes a catch whereby the lever in use may engage said oiLtch to hold said broale assfembly in a locked position.

Preferably, biassing means are provided whereby the braking members may be held in a non-operative position unless the lever is actuated, and whereby the braking members may return to a non-operative position when the lever is released. In one embodimer. the biassing means may include a 0 compression spring.

In a further aspect this invention resides broadly in a Sbrake assembly including:braking means adapted to be selectively engaged with a rotary member to brake said member, wherein said braking means includes a pair of opposed braking shoes; actuation means operatively connected to said braking means for forcing said braking means into engagement with said rotary member, said actuation means including a manual a 'a actuating lever operable for forcing said braking means into selective engagement with said rotary member and which may be Smoved from an inoperative position to an applied position, at which said braking means maintains said rotary member stationary; holding means for holding said lever in said applied position; adjustment means for centralising said braking members -I about said rotary member, and biasing means for biassing said braking means to an inoperative position, characterized in that said levet includes an abutment engageable with the outer face of one braking member and about which said lever may pivot and connecting means connecting the lever to the other braking 000004l 0 0'00 o 0* 00 0*00 10 0 *0 P 0 00C 0 00 00 O 0 00B 0 0O 0 00 00 0 member.

Preferably the braking meanis include support means for supporting said actuation lever whereby said lever is operable to move said braking means in opposed directions to engage opposite portions of said rotary member. Preferably the support means is adjustable as is the engagement of said lever with said opposed braking members.

In a further aspect this invention resides broadly in a brake assembly provided with an actuating lever which may be operated in one direction for applying a selectively variable braking force to a rotary member or in a further direction to a lock position for applying a locking braking force to the rotary member.

In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a number of preferred embodiments of the ivention.

As shown in fig. 1, the brake assembly 10 is a contracting drum brake assembly having a pair of opposed braking shoes 11 and 12 interconnected by a adjustable pivot I, arrangement 13 whereby the shoes 11 and 12 may be arranged concentrically about the drum 14 which is fixed to the shaft to be braked. Each shoe includes a fabricated backing strip 16 which is welded to a respective pivot plate 17 to 6 extend partway around the drum 14 and, opposite the pivot 13 outwardly at 18 and 19 so as to form mounting lugs for the actuating assembly 20. Preferably the pivotal connection connecting plates 47 is adjustable.

The actuating assembly 20 is in the form of a bar like .10 lever 21 provided with an end flange 22 which extends sooo*r 9 Ssubstantially parallel to the lugs 18 and 19 and which is connected thereto by a throughbolt 23 extending through the lugs 18 and 19 and through the flange 22. The inside face 24 of the bolt head 25 is part conical so as to form a pivot bearing about which the flange 22 may pivot. The outer end 26 of the flange 22 engages the outer end of the adjacent lug 18 while the inner end of the flange 22 is apertured and threaded to receive an adjustment bolt 27 which engages the inner end of the lug 18.

The actuating lever 21 passes beyond a catch assembly which is provided with a retaining plate 31 under which the lever 21 may be engaged. The lever 21 is provided with an actuating handle 33 at the end of the lever remote from the flange 22 and a compression spring 29 is arranged about the bolt 23 between the lugs 18 and 19 to maintain the braking shoes 11 and 12 in a disengaged position when the lever 21 is T~ i~l*liYilll- i~_Xlt Si7 jnot actuated or looked. An eccentric support member 34 is !i supported beneath the lower shoe 12 so as to maintain the shoes in their concentrically arranged position spaced from the drum 14 whereby shoe drag is prevented in the inoperative position.

Fig. 2 illustrates a brake assembly 40 similar to the brake assembly 10 of fig. 1 and wherein there is provided an VI adjustment means 41 for centralising shoes 11 and 12 about V the drum 14. In addition, there is provided a shaped washer 42 positioned intermediate the head 25 of bolt 23 and flange 22 of the actuating assembly 20. The apex 43 of washer 42 forms a pivot bearing about which the flange 22 may pivot.

In use the handle 33 may be raised whereupon the actuating lever 21 pivots about the bolt 27 and draws the shoes 11 and 12 together via the interconnecting bolt 23.

Alternatively the handle 33 may be pushed downwardly so that it pivots about the outer end 26 of the flange 22 and again L| draws the shoes together through the interconnecting bolt 23.

i 0 It will be seen that a greater braking force is applied when I the lever 21 is pushed down as opposed to when it is lifted 1 "upwardly as a result of the leverage provided between the connecting bolt 23 and the bolt 27 on the oie hand and the end 26 of the flange 22 on the other hand.. The bolt 27 may be adjusted to position the actuating lever 21 in any desired position relative to the catch assembly 30 so that when the 8 lever 21 is pushed downwardly as in fig. 1 or upwardly as in fig. 2 to engage under or over the catch plate 31 respectively, it will hold the brake shoes 11 and 12 engaged about the drum 14.

B Accordingly, in use, the handle may be lifted up to brake the drum 14 or it may be pushed downwardly and sideways under the latch 31, pivoting about the bolt head 25 in the process, to hold the brake drum in the locked position.

It will of course be realised that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto as would be Pipparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as is herein set forth.

I 4A j i i 1 2

Claims (7)

1. An external contracting brake assembly including:- a rotary member to be braked; a pair of opposed braking shoes pivotally connected together about a fixed pivot assembly for pivotal movement between an engaged attitude engaged with said rotary member and disengaged attitude operatively spaced from said rotary member; supporting members on each said shoe remote from said fixed pivot assembly and arranged in spaced apart relationship whereby they may be moved together to pivot said braking shoes to said engaged attitude; a manual actuating lever extending across a face of one supporting member remote from the other supporting member and having an abutment engageable with said face, and connecting means connecting said other supporting member tr Isaid lever at a position spaced from said abutment whereby said i lever may be pivoted about said abutment to an applied position at which said braking shoes are disposed in said engaged attitude.

2. A brake assembly as defined in claim 1 and including holding means for holding said lever in said applied position.

3. A brake assembly as claimed in Claim 1, or Claim 2 wherein said holding means is a catch engageable with said actuating lever.

4. A brake assembly as claimed in any one of the preceding clams, wherein said connecting means is adjustable. i.

A brake assembly as claimed in any one of the preceding claims, wherein the pivotal connection between said brake shoes is adjustable for centralising said shoes about said rotary member.

6. A brake assembly as claimed in any one of the preceding claims, wherein biassing means are provided for biassing said i~ M braking shoes to said inoperative position.

7. A brake assembly substantially as herein described in the accompanying drawings. S4i I 4 I I I A s L- I A k:e==Eha-;e-4:1 4 3(l q I I t4q A J4.1- 4 A 4 4 3;1-4-1 R -bile ageofflow- A j DATED THIS fourteenth THEODORE WILLIAM REINHOLD DAY OF September, 1987. by PIZZEY COMPANY PATENT ATTORNEYS 4 tOtI )0 14 4 0 4? 4? F? o 'F 14 4? 00F~~' 4? 4 OF, 0 o 0 0 40 4? 14 40 o oo F, 44 4? 4 4 4 00 4? 44 414 4 4 44 4FF F 0 F 414 L