USRE20733E

USRE20733E - Brake mechanism

Info

Publication number: USRE20733E
Authority: US
Priority date: 1933-03-25
Publication date: 1938-05-24
Also published as: US2028491A

Description

May 24, 1938. B. A. BARRETT ET AL 20,733

BRAKE MECHANISM Original Filed March 25, 1935 2 Sheets-Sheet 1 INVENTORS ATTORN EYS May 24, 1938. B. A. BARRETT ET AL BRAKE MECHANISM Original Filed March 25, 1953 2 Sheets-Sheet 2 IVENTORS Ber/an fl Bar/ail 660%: E ierreaa/l BY W Y M, ATTO R N EYS Reieeued May 24,.l938

BRAKE MECHANISM Berton A. Barrett,-Manila, P. 1., and George E.

Perreault, Bronxville,.N. Y., assignors to Wag- 'ner Electric Corporation, St. Louis, Mo., a corporation of Delaware Origihal- No. 2,028,491, datedJanuary 21, 1936,

Serial No. 662,726, March 25, 1933.

Application for reissue December v13, 1937, Serial No.

18 Claims.

This invention relates generally to brake systerns, and has particular reference to improvements in brakes for automobiles. invention is, as will be apparent later on, not limited to automobile use, as it can be employed in connection with other wheeled vehicles where it is desired to hold a set of brakes in braking or applied condition while'the vehicle is at a standstill. a

One object of the inventionis to provide an improved brake mechanism which will hold the brakes applied'to prevent movement of the vehicle after the vehicle has been stopped. This is accomplished by using a feature which will act automatically, when the vehicle is brought to a standstill with the brakes applied, to hold the brakes locked in braking position and thereby prevent movement of the vehicle. ,Thls makes it unnecessary for the operator to hold the brakes on by, for example, holding-the brake pedal of an automobile down to prevent the automobile from -moving.

Another object is to provide a mechanism having the advantages just pointed out, which is so constructed that there will be no interference with the use of the brakes to retard movement of the vehicle while the vehicle is moving.

Still another object is to provide a simple mechanism whereby the brakes may readily be released after they have been locked in braking position under control of the automatic feature above referred to. This release mechanism is preferably so arranged that it may be operated alone or as a preliminary incident to operation of the accelerator when the invention is used in an automobile.

with the foregoing and other objects and advantages in view, the invention consists in a novel construction and relation of parts, the novel fea tures of which are pointed out in the appended claims, and embodiments of which are illustrated in the drawings which accompany and form a part of this application.

In said'drawings:

Figure 1 shows the invention in one form which it may have when applied to an automobile equipped with what are usually referred to as mechanical brakes;

Figure 2 shows, partially in section, details of the form of inertia device employed in the con struction illustrated in Figure 1;

. Figure 3 shows in detail the form of one-way valves used in the brake control piston employed in the apparatus oi Figure 1;

However, the

Figure 4 shows a modification of the inertia device shown in Figure 2;

Figure 5 illustrates another embodiment of the improvements in an automobile equipped with mechanical brakes;

Figures 6 and '7 illustrate the invention applied to an automobile equipped with hydrauli brakes, and

Figure 8 is a sectional view through. a one-way valve such as employed in the constructions illustrated in Figures 6 and 7.

As previously stated, the apparatus shown in Figure 1 includes the improvements in the form they would take when applied to an automobile equipped with mechanical brakes controlled by a foot pedal or lever Ill. This lever is pivoted at II and is rigid with an arm i2. connected by a link or rod l3 to the brake applying mechanism.

Pivoted to the lever 10 is a link M which is in turn pivoted to a rod I5 forming part of a piston working in a fluid containing cylinder l6. Secured on the rod I5 is the piston head ll. This head may be provided with any suitable form of a one-way valve mechanism. The construction employed in the apparatus of Figure 1 includes a number'of balls l8 (Figure 3) each held against an opening through the piston head by a spring l9 and a retaining nut 20. The construction is such that when the piston is thrust in one direction (downward in Figure 1) the fluid in the cylinder can pass freely through the orifices in the piston head I1 and nuts 20, but the ball valves l8 will prevent a return flow through the piston head.

Communicating with the cylinder is a circulatory system for the fluid comprising pipes or

tubes

22 and 23. These tubes are connected to pipes or

tubes

24 and 25.

Mounted between the tubes 28 and is an inertia controlled valve which is held open while the automobile is accelerating or decelerating and which automatically closes when the car comes to a stop, thereby closing or preventing circulation through the

pipes

23, 25, 24, 22. When the brake lever I0 is operated and the piston ll thrust downward in the cylinder I6 the piston is free to return if the inertia valve in the passageway is open. If, however, the automobile is brought to a stop the inertia valve is closed and the fluid which is trapped above the piston head ll will hold-the piston in the position to which it was moved by operation of the brake lever, resulting in the brakes being locked in' braking or applied position.

in Figure 2. It comprises a casing 28 and a cross member 21 provided witha passageway 23 in communication with

thetubes

24 and 25. The

cross member 21 also is provided with a vertical passage in which a valve member II is supported for sliding movement: The member 3i has an opening or slot 32 which, when the automobile is accelerating or decelerating, is in alignment with v the passageway 29 but which is moved out of alignment with the passageway when the automobile comes to a rest. The member 3i is moved in one direction by a ball or other suitable form of weight 33 suspended on a cord or flexible strip 34 secured to the lower end of the member 3i. The weight 33 rolls along the underside of a cross plate 38 extending from side to side of the casing 23. The upper end oi the member 3i is threaded and provided with suitable adjusting nuts 31 and a disk 33 for holding a spring 39 in position on the member. The spring 39 is of 'suflicient strength to raise the member 3| as the weight 33 approaches or comes to rest in the position shown in full lines in Figure 2. Movements of the weight 33 and its suspending element 34 are controlled to a certain extent by the guide rollers 4i.

When the at is standing still with the valve I member 3| in the position shown in Figure 2 opof the weight 33 and the connected parts when the automobile is moving, particularly when it is accelerating and decelerating. During such movements the valve 3| is open and the brakes may be used without any interference by the inertia controlled device.

In order to permit freeing the brakes when the car has been stopped with the brakes applied, a by-pass is provided containing a valve which is normally closed but which can be opened to allow a return flow or the fluid in the cylinder I6 and thereby allow the brake lever and connected parts to return to their normal or brakes-off position. This by-pass and valve mechanism includes pipes or tubes 42 and 43 communicating with a chamber in a valve casing 44. Rotatable in this casing is a valve member '48 rigid with a crank arm 41 connected to one end of a link 48 which is pivoted to one end of a lever, pivoted at 49, that lever. in turn being pivoted to a rod 53 passing through the floor board of the automobile and terminating in a button or knob 5|. Pressureon the knob will swing the valve member 46 to a position where communication will be established through the tubes 42 and 43 so that fluid trapped above the piston Il may circulate through the valve and enter the cylinder below the piston thereby allowing the piston to return to its normal position and permitting a like return of the brake lever and connected parts. A spring 52 on the rod 5|! normally holds the valve 46 closed. The button or knob 51 is preferably placed adjacent to the accelerator and preferably arranged to project above the accelerator. This permits operating the valve 46 alone to release the brakes or the knob 5i may be depressed in advance of the accelerator because of the fact that the knob extends above the accelerator. This arrangement, while not shown in Figure 1,

is ill izistrated in another form in Figures 5, 8, and

Figure 4 shows a modification of the inertia valve 26 shown in Figures 1 and 2. It comprises a valve casing 54 connected to the pipes and 25 and containing a valve chamber 53. Sliding through a suitable opening in the valve casing is a member 56 provided with two

openings

31 and 33. The member 54 is pivotally connected at one end to a link 33 which in turn is pivoted at ill to a member 3|. This memberis pivotally connected at B2 to the upper end 01' a lever 33 pivoted at 64 and carrying at its lower end a weight 65. In Figure 4 the parts are all shown in the position they assume when the automobile is standing still. When the car is moving, and

particularly when it is being accelerated or delation of the fluid from the cylinder. When the car comes to a stop with the brakes applied the parts will again assume the position shown in Figure 4, thereby closing the valve and trapping the fluid above thepiston I1 and holding the brakes locked.

In Figure 5 the improvements are shown in another form which they might take when applied to an automobile equipped with mechanical brakes. In this form, a different kind of an inertia device is used.to control a by-pass valve by means of an electric circuit including one or more switches. The brake lever Ill, link I4, piston rod i5, cylinder I6, and piston head i1 are constructed and operated in the same way as previously described in connection with the apparatus of Figure 1. The circulatory system shown in Figure 5 comprises tubes 61 and 68 connected to the cylinder I6 above and belowthe piston head I1, and a valve casing 63 containing a passage '10 in communication with the passages through the tubes. member 13, containing an opening or slot 14, and carrying at its lower end a return spring 11 and the same nut and disk arrangement as previously described. The upper end or the valve member or rod 13 extends into a solenoid coil -l8 and is movable in one direction by the solenoid and in the other by the spring 11. Normally, the valve member 13 is in a position where its passageway 14 is in alignment with the passageway through the valve casing but when the brakes are applied, and the car comes to a stop, the solenoid operates to shift the valve member upward to cut oil the return flow of fluid from the cylinder IS.

The current for the solenoid is supplied by a battery 8| or other suitable source of supply,

through a circuit which includes an inertia valve -tric circuit. When the automobile is moving and particularly when accelerating and decelerating the ball 34 will, because of its inertia or momentum, be held away from the contact points ll, thereby causing the circuit through the solenoid to be open so far as the contact or connection is concerned.

Sliding in the valve casing 69 is a valve.

The curved surface upon which the ball as moves is oi! such a radius as to make it, certain that the ball will roll to the circuit.making posi tion on any grades likely to be encountered. It is very seldom that road surfaces exceed a grade and the curved surface referred to will have its surface inclined in excess of the 10% grade mentioned so that for any common grade there will be an eilective inclination causing the ball to roll to the contact position.

The electric circuit may also include a switch designated generally as ll. .It may be of any suitable construction and includes an arm 02 resting upon an extension 03 on the brake lever. An arm I4 is rigid with and movable with the arm 92 and is connected by a spring II to an adjacent stationary part. This switch is not es* sential although it serves a valuable purpose in preventing drain on the source of current supply.

When the brake lever III is operated to throw on the brakes the spring 85 will throw the switch to close the circuit at that point. Then when the ball or roller 84 comes to rest between the contacts II it will establish the circuit through the inertia device 02 and the solenoid II will with a return spring I".

operate the valve member 13 to shut of! the circulatory system and trap the fluid in the cylinder it above the piston II to lock the brakes in applied position.

To release the brakes a second switch Iill is employed. This switch may be of any desired construction and comprises an arm I02 connected by a link III! to the lower end ofa lever ill which is pivoted at III! and is equipped The upper end of the lever IN is connected by a link Ifll to a pedal "II which is preferably adjacent to the throttle or accelerator pedal I". The arrangement is such that the pedal Hi8 may be operated alone to throw the switch III and thereby release the brakes, or the pedal may, on account of its being set ahead'oi the accelerator pedal I", be operated first or as a preliminary incident to, operating the accelerator pedal.

The apparatus in Figure 6 is adapted for ap- H plication to automobiles equipped with hydraulic brakes. It includes a fluid containing cylinder II. and a piston head Ill connected by a rod Ill and a link II! to the brake lever ID. The piston head is not perforated or equipped with one-way valves such as shown in Figure 3, but

.expels the fluid to operate the brakes when the 423 for transmitting the brake operating fluid to the brake mechanism. A loop I2 of the tubing transmits the fluid through an inertia controlled valve which is designated I26 and is the same as the one shown in detail in Figure 2. A section I25 01' tube connects the loop I24 with the tube I23. When the fluid is expelled from the cylinder IIB it is forced through the one-way valve I22 and may circulate through the inertia control valve if the automobile is in motion and particularly when the automobile is being acdelerated or decelerated. The one-way valve I 22 prevents the return of the fluid from the brake tube I21 and when the automobile comes to a stop the inertia control valve I26 will be closed and as a result the fluid expelled from ,be locked in braking position.

the cylinder will be trapped, thereby causing the brakes applied by movement of the lever II to To release the brakes, connections including a valve I21 afford means for letting the braking fluid return to the cylinder while the inertia valve I20 remains closed. The valve I21 is similar to the valve 4 previously described and has its operating arm l2! connected by a link I28, pivoted lever Ill! and link III to a pedal I32. This pedal is placed like the pedal I" previously referred to and may alsobe operated singly to release the brakes or as a preliminary incident to operating the accelerator.

In the embodiment illustrated in Figure 7 the electric circuit and ball form of inertia device previously described are applied to a hydraulic I brake system. The one-way valve I22 previously described is employed and the inertia device controls a solenoid operated valve I like the one previously described when referring to Figure 5. In the operation of the apparatus of Figure '1 the liquid expelled from the brake operating cylinder H8 is trapped by the one-way valve I22 and by the solenoid operated valve "(when the automobile comes to a stop. This is because the ball 84 will close the circuit when the movement of the vehicle has substantially ceased, thereby causing the solenoid valve to close the circulatory system against return of the brake fluid. To release the brakes, the circuit is broken by operating a pedal I to throw a switch iii in the manner previously described when explaining the mechanism oiFigure 5.

The inertia devices are so constructed and adjusted that they will perform their functions when the vehicle is brought to a stop on an incline, or when the vehicle is travelling in either direction and brought to a stop, as. for instance, when backing an automobile and applying the brakes. This is one reason for the curved bottom or track for the balls 81 in the electrical equipment. The construction of thecurved bottom or track to ensure causing the ball to make contact .on different grades, has already been pointed out.

In explaining the invention, the novel construction and the relations of the parts shown in the drawings have been set forth in detail, but it is not the desire to be limited by the drawings or explanation in any way except as specified in the following claims.

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

l. A vehicle brake system comprising means under the control of the operator for applying and releasing the brakes, means automatically rendered eflective by bringing the vehicle to a stop for holding the brakes applied, and means under the control of the operator for disabling said holding means at will.

2. A vehicle brake system comprising means under the control of the operator for applying and releasing the brakes, means automatically rendered effective by stopping the vehicle for holding the brakes applied, an accelerator mechanism comprising a member movable by the operator to control the engine speed, and adevice comprising a member movable by the operator to render the aforesaid holding means ineffective preliminary to movement of the accelerator operating member.

3. A vehicle brake system comprising an operating member movable by the operator to apply the brakes, an inertia device, a device connected to the operating member and controlled by the inertia device for holding the brakes appliedwhen the vehicle is brought to a stop, and a device whereby the operator may disable the holding device and release the brakes at will.

4. A vehicle brake system comprising an operating member movable by the operator to apply the brakes to stop the vehicle, an inertia device. means controlled by the operating member and rendered eflective by the inertia device when the vehicle is brought to a stop for holding the brakes I applied, and means under the control of the'operator for rendering the inertia device ineflective and releasing the brakes preparatory to starting the vehicle.

5. A vehicle brake system comprising a lever operable to apply the brakes, an inertia device, mechanism controlled by the inertia device for holding the lever in brake applied position as soon as the vehicle comes to a stop, and means whereby the operator may render said mechanism inefiective before starting the vehicle. a

6. A vehicle brake system comprising an operating member movable by the operator to apply the brakes to stop the vehicle, an inertia device, means controlled jointly by the operating member and the inertia device for holding the brakes applied when the vehicle has been brought to a stop, and a device under the control of the operator for rendering the holding means ineil'ective while the car is at a standstill.

'7. A. vehicle brake mechanism comprising an operating member for applying the brakes, a piston connected to the operating member and a fluid containing cylinder in which the piston reciprocates, one-way valves in the piston, a circulatory system connected to the cylinder, an inertia device, a valve controlled by the inertia device for closing the system and thereby holding the piston in the position to which it is moved by the operating member when applying the brakes, and a device under the control of the operator for releasing the piston to free the brakes when desired.

8.'A vehicle brake system comprising an operating' member movable by the operator to apply the brakes, an inertia device, mechanism comprising a valve controlled by the inertia device for holding the brakes applied when the vehicle is brought to a stop, asecond valve operable to release the brakes, and connections operable by the operator for opening said second valve to release the brakes.

9. In an apparatus of the character described,

a brake operating lever, apiston connected to said lever and provided with a one-way valve vmechanism, a' fluid containing cylinder in which lever, an engine accelerator mechanism comprising a member movable by the operator, an inertia device, means controlled by the inertia device when the vehicle comes to a stop for holding the aforesaid operating lever in the brake applied position, and means operable in advance of and as an incident to operation of the accelerator for disabling the brake holding devices when starting forward movement of the vehicle.

11. An automobile brake mechanism comprising a lever for operating the brakes, an engine accelerator mechanism comprising a manually operable member, an inertia device, means rendered eil'ective by the inertia device when the automobile comes to a stop for holding the brake operating lever in brake applying position and with the brakes applied, and a brake releasing device comprising a member adjacent to ,the accelerator operating member andoperable singly or in combination with the accelerator member.

12. A vehicle brake system comprising means under the control oi! the operator for applying and releasing the brakes, means comprising a circulatory system normally open while the vehicle is moving, and an inertia device for closing the circulatory system to hold. the brakes applied, said inertia means being rendered effective by bringing the vehicle to a stop, and a device under the control of the operator for rendering said means ineffective at will.

13. In a motor vehicle braking apparatus pro-,

vided with means for actuation by the vehicle operator to apply the brakes, means for holding the brakes in applied position which comprise a control member in the form of a ball capable oi. movement under the influence of gravity and of inertia, said ball being so mounted that gravity tends to cause it to move to the position which it occupies when the brake holding means is op- -erative, and that inertia during a predetermined rate of deceleration of the vehicle moves it to another position.

14. A vehicle brake system comprising means a for actuation by the operator to apply the brakes,

and means other than said first named means for holding the brakes in applied position, said last named means comprising a control member in the form of a rolling ball adapted to be moved by gravity to the position it occupies when the brake holding means is operative.

15. In a motor vehicle provided with fiuid-actuated brakes, valve means for preventing release of the brakes from applied position, and means comprising a rolling ball for controlling said valve means, said ball being so mounted that gravity tends to cause it to assume a position under which the valve will be closed, and that inertia during deceleration of the vehicle causes it to assume a position under which the valve will be open.

16. In a motor vehicle provided with brakes and means for normally controlling the application and release of the brakes, other means for preventing release of the brakes from applied position, power means for controlling said other means, and means under the control of gravity for determining whether the power means be operative or inoperative.

17. In a motor vehicle provided with brakes and means for applying the brakes, means for preventing release of the brakes from applied position, power means for operating said release preventing means, and means for controlling said power means and comprising a rolling ball which is so mounted as to be moved by gravity to a position causing said release preventing means to.

be operable and to be moved by the action of inertia during deceleration of the vehicle to a position causing said release preventing means to be inoperable.

18. In a motor vehicle provided with brakes and means for normally controlling the application andrelease of the brakes, other means for preventing release 01 the brakes from applied position, a solenoid and a circuit including a source of current for operating said other means, switch means in said circuit and comprising a rolling ball for controlling said circuit, said ball being so mounted as to be moved to switch-closed position by gravity and to switch-open position by the action of inertia during deceleration of the vehicle, and a second switch in the circuit under the control of the operator for breaking said circuit.

BERTON A. BARRETT. GEORGE E. PERREAULT.