| GB1218173A | 1971-01-06 | |||
| EP0202845B1 | 1991-01-02 | |||
| FR2601310A1 | 1988-01-15 | |||
| DE1801007A1 | 1969-05-08 | |||
| DE3618509A1 | 1987-12-03 | |||
| DE3906141A1 | 1989-09-21 |
| 1. | A selfblocking, hydraulic brake booster, operated by the inertia energy of the vehicle controlled, by the pilot by the pressure (16A) of the primary hydraulic or pneumati circuit, acting on a pushing surface limited with respect to the friction surfaces so as to prevent the blocking the reof, and on a hollow piston (4) with a spring (5) acting against its sliding, the setting thereof adjusting the secondary braking effect, for the movement of a small pi¬ ston (7) with a return spring (8) housed therein in tappet contact with an antifriction, or roller, slidingblock (13), towards a cam (15), out of one piece with the wheel' hub or with the brake's disk, with a consequent alternate movement thereof for the pumping at high pressure of hy¬ draulic oil into a pushing cylinder (24) onto the friction surfaces, with a continuous return discharge to the respec tive feeding reservoir (22) through an adjustable nozzle (25) with fix capacity, or through a valve controlled by the primary pressure acting onto a small piston (26) with discharge distribution lights adjustable due to the anti¬ blocking effect, relating to the rotation speed of the dis or of the drim of the brake, so as to determine an immedia te interruption of the braking in its primary position. |
| 2. | A selfblocking, hydraulic brake booster according to claim 1, characterized in that the action thereof is deter mined by the pressure of the primary, hydraulic or pneuma tic circuit (16A), controlled by the pilot, acting also on to a hollow piston (4), sealingly sliding in a cylinder, placed on a vertical to the wheel's hub, in support to a small pumping piston (7), with groove lights (19), anular (20), small automatic feeding valve (21), retention (23) and return spring (8) for its getting nearer, by means of fulcrated antifriction or roller slidingblock (13), kept in tappet contact by a pinspring (14), with a cam (15) ou of one piece with the wheel's hub which determines, accord ing to its rotation, an alternate motion forming a pumping system with variable capacity according to the primary pressure, upon the pilot command, which acting onto the setting of the spring (5), adjusts the run of the small pumping piston (7) and the consequent capacity thereof. |
| 3. | A selfblocking, hydraulic brake booster according to the precedent claims, characterized, for its antiblock¬ ing function, in an adjustable nozzle (25) with fix capa¬ city with continuous discharge of the secondary pessure (16B), acting on the friction surfaces for a lowering of its values at each capacity reduction of its pumping sy¬ stem according to the rotation of its control cam. |
| 4. | A selfblocking, hydraulic brake booster according to the precedent claims, characterized, for its antiblocking and immediate braking interruption function, in a distribu tor controlled, by the pilot, by the primary pressure, wit variable capacity, adjustable for the antiblocking and • */ • • • maximum capacity effect for an immediate discharge of the secondary pressure. |
| 5. | A selfblocking, hydraulic brake booster according to claim 1. characterized, for the linearity of its secondary pressure (16B) generated by an alternate system as already described, in a stabilizing valve (32), controlled by the primary pressure acting onto a small piston (A), sealingly sliding in its cylinder (C), for the charging variation of a spring (D) acting againts the secondary presεule, by means of a nozzle (G) with variable capacity, with an ap¬ propriate pushing relation, with a tierod (E), for coupl¬ ing and adjusting of its setting and of return spring (H) for the maximum capacity of nozzle (G) to the discharge of the control pressure, for an immediate interruption of the brakin . |
| 6. | A selfblocking, hydraulic brake booster, according to claims 1 and 5, characterized, for the control of the fric tion jaws for drum brakes, by a double small cylinder (31) having a central support, for the respective feeding and discharge channels of the respectively cyindrical and crown pushing surfaces. |
| 7. | A selfblocking, hydraulic brake booster, according to claim 1. characterized in its selfadjusting braking effect on each single front or back wheel of the vehicle, due to the proportional push on the friction surfaces according to the rotation speed of its control cam and to the inertia of the vehicle, with a consequent capacity and pressure varia¬ tion of its pumping system that allows the elimination of the traditional braking correctors. |
| 8. | A selfblocking, hydraulic brake booster according to claims 1 and 7, characterized, for the tappet control of its small pumpin piston (7), in an antifriction sliding block (13) with a large contact surface on the circumfe rence of the control cam (15), always kept in its correct rotation angle by a friction hinged pin (12) onto the small contact lever (10), operated by the return pin spring (14) against the blocking of alignment (12A). |
| 9. | A selfblocking, hydraulic brake booster according to claims 1 to 7, characterized, for the tappet control of its small pumpin piston (7), in a small lever (10) of appro¬ priate length with forkends, for the support of an anti¬ friction roller on the way of the control cam (15). |
| 10. | A selfblocking, hydraulic brake booster according to the precedent claims, characterized in its low working pressure by the pilot, of its primary control circuit, wit consequent functioning safety for being considered, for its reduced working, as a reserve system. |
The present invention concerns a self-blocking, hydraulic brake booster for vehicles, of the kind using the original primary circuit, controlled by the driver, lowering the working pressure and avoiding the need of the traditional brake booster.
Actually, very expensive and complex systems are used, al with electronic support, for improving the efficiency of the braking of the vehicles, avoiding the blocking of the wheel especially in conditins of low coefficients of adhe rence to the street, but said systems have a high vulnera bility rate and are subject to frequent damages.
The device according to the present invention, due to the use of the original primary circuit controlled by the dri ver, that lowers the working pressure avoiding the need o the conventional brake booster with a greater functioning safety so as to be considered a reserve system, exploits the inertia energy of the vehicle for operating a hydrodi na ic pumping mechanism with variable capacity and with high pressure on the friction surfaces connected to the r tation of the wheels, with the pressure discharge thereof at every slowing down or blocking.
• • • / • • •
The most considerable advantages of the device according t the present invention consist in the complete automatism o the brake booster and in the high f nctionality thereof.
The present invention will be described more in detail he- reinbelow relating to the enclosed drawings that show some preferred embodiments thereof.
Figures 1 and 2 show a square section of a self-blocking, hydraulic brake booster according to the present invention for the control of disk brakes.
Figures 3 and 4 show a square section of a variant of the self-blocking, hydraulic brake booster for the control of the jaws of drum brakes.
The figures show a self-blocking, hydraulic brake booster consisting of a cylinder comprised in the plier of a brake 2, or otherwise fixed on the vertical of the wheel's hub i which it may slide, sealed by small rubbers 3, the hollow piston 4 shown in dotted lines in figures 1 and 2, pushed to the end of its run by a spring 5 kept by cup 6 on ela¬ stic ring 6A.
In said hollow piston 4 the lower part of a small piston 7 may slide, pushed by a spring 8 on the end-run metal ring guided by the cup 6 with the dust-cover bushing 6B.
The small lever 10, having its fulcrum in pin 11, has hing ed on friction pin 12 sliding-block 13 pushed by the pin- spring 14 in tappet contact with the half-spheric end of the small piston 7 against the alignment stop 12A.
A cam 15, out of one piece with the wheel's hub or to the one of the brake's disk 16, may freely rotate in axis with the sliding-block 13 without touching the same until the pressure of the primary circuit 16A - hydraulic or pneuma- tic - shown by P on the direction arrows and controlled by the pilot, acting on the piston 17 of reduced diameter due to a limited push on the friction surfaces so as to preven the blocking thereof, and acting through the tube 18 on th hollow piston 4 causing the movement thereof towards the cam 15, causes the contact of the sliding-block therewith and the consequent alternate motion of the small piston 7, called by the return spring 8 at the lower run-end deter¬ mined by the metal ring 9.
The sliding of the upper end of the small piston 7 in its cylinder 7A, fed through the groove canalization 19, anu- lar 20 and the small automatic valve 21, with the liquid of the tank 22, may pump at high pressure through the re¬ tention valve 23, hydraul^ oil into the chamber of one piston 24, for the push on the friction surfaces having a greater diameter than the primary one 17, for the maximum braking effect desired or for an uncontrolled need of the pilot .
Ad adjustable nozzle 25, by means of a conical screw 25A having a fix and continuous capacity, adjusts the dischar¬ ge of the pressure onto the piston 24 and the consequent blocking of the brake for the stopping of the cam 15 and o pumping 7.
The primary pressure with its reduced braking effect con¬ nects the blocking and the release of the brake. Relating to the primary pressure, adjusted by the pilot, the spring 5 is compressed, the setting thereof determining the run o the small piston 7 and the capacity thereof relating to th rotation speed of the cam 15, for the self-adjusting brak¬ ing and anti-braking effect.
As an alternative to the adjustable nozzle with fixed capa city 25 for an immediate interruption of the braking, the primary pressure acting also on a small piston 26, sealing sliding on small rubbers 27 and 27A in its cylinder, over¬ coming the resistance of spring 28, determines by means of the adjusting of run-end 29 the discharge capacity of the secondary pressure, through the position of the anular light 26A, of the small piston 26 with respect to the one 26B to reservoir 22, which due to gravity keeps operative the whole pumping system.
When the discharge of the primary pressure occurs, control led by the pilot, the spring 28, calling back small piston 26 to its first position, allows an immediate discharge of-
• • •/ • • •
the secondary ne through the width of its lights, for an immediate interruption of the braking.
For what concerns the control of the jaws of dram brakes, shown in the variant of figures 3 and 4, a double small cy linder 30 with concentrical chambers, with small discharge valves 30A, may transmit the primary pressure as well as the secondary pressure to the friction surfaces 31, throug the respective channels 16A and 16B.
Relating to the detail shown with dotted lines in figure 4 a valve 32 controlled by the primary pressure, acts on small piston A, sliding in sealing conditions in small rub bers B in its cylinder C, for the movement, by means of th setting of a spring D adjustable by tie-rod E with sliding head in room F, of the occlusion nozzle with variable capa city G, elastic and moderable, when the discharge of the pressure of the secondary circuit occurs, without trasmit- ting any vibration of its pumping system alternated to the primary ciruit, balanced by spring D acting on the capaci¬ ty of nozzle G.
To the discharge of the primary pressure on small piston A controlled by the pilot, the one of spring D follows until the contact of the head of the tie-rod C on stop ring I, and consequent reaction of the spring H with a sufficient setting for the opening of the nozzle G for the immediate interruption of the braking.
• • •/ • • _
Next Patent: APPARATUS FOR LIFTING AND TRANSPORTING MUTUALLY SIMILAR OBJECTS WHICH ARE MUTUALLY OF THE SAME SHAPE