A SERVO FRICTION-CLUTCH DEVICE FOR AUTOMATING THE CLUTCH OPERATION IN MOTOR VEHICLES OF ANY KIND

Abstract: A servo friction-clutch device for automating the clutch operation in motor vehicles of any kind, said device comprising a cylinder that includes one or two seal chambers, (10, 11) a membrane (12) running within said cylinder, said membrane (12) being connected through a shaft (13) and some mechanical means (14, 15, 26, 26') to the clutch pedal or to the equivalent leverage; a three-way solenoid valve (1) whose commutation is actuated through the accelerator pedal or gas pedal, or through the acceleration circuit of the vehicle; a small vent piston (21) which is in communication with said cylinder and is connected direct or indirect to the clutch pedal or to said equivalent leverage and is operatively actuated by the vehicle carburetor; and a one-way vent solenoid valve (30) that is actuated by a frequency generator connected to the tachometer.

Description: The present invention relates to a servo friction-clutch device for automating the clutch operation in motor vehicles. More particularly, the present invention relates to a device for actuating the friction-clutch in a way similar to that obtained through the driver's stepping on the clutch pedal, in any kind of vehicle ride, without intervention in a drastic way on the structure of the vehicle itself. The device which is the object of the present invention, differently with respect to the already known devices, allows the driver to employ compression slowing down at any time, both when the vehicle is riding at a high speed and when it is at a stop, because a very simple and reliable apparatus is provided. Moreover, the device according to the present invention allows the driver to proportion at his will the slipping of the friction with respect to the load conditions of the vehicle and to the number of revolutions of the engine, by just actuating the gas pedal through short strokes. This object and further objects of the present invention are obtained through the servo friction-clutch device of this invention by coupling to said device, which is connected to the clutch pedal or possibly to the corresponding leverage, a small vent piston means which is connected through mechanical or pneumatic means to the carburetor and operates in the starting phase, or anyway at a low number of revolutions of the engine, as well as a one-way vent solenoid valve which is actuated by a frequency generator and starts operating instead of said small vent piston at a predetermined speed of said vehicle, so that the disengagement of the friction-clutch followed by the next engagement when the vehicle is riding are made possible. Thus, it is a specific object of the present invention a servo friction-clutch device for automating the clutch operation in motor vehicle of any kind, said device comprising cylinder means consisting of an air-seal double chamber, as well as three-way solenoid valve means, said device being characterized in that said two chambers of said cylinder means are separated by sliding membrane means which are connected through shaft means tightly running through one of said chambers and by mechanical means, to the friction-clutch pedal or to the equivalent leverage; said three-way solenoid valve means having one of their ways connected to said cylinder means, another one direct communicating with the atmospheric pressure, while the third way communicates with vacuum generating means, the commutation of such ways being actuated by the acceleration or speeding up means of the vehicle, venting means being connected to the chamber of said cylinder means in which said shaft means can run, said venting means being operatively actuated by the carburetor of said vehicle and being connected, direct or indirect, to the clutch pedal or to its equivalent leverage; check-valve or non-return valve means for air-flow inlet into said chamber as well as one-way vent solenoid valve means connected operatively with frequency generator means. It is a further object of the present invention that of supplying a device of said kind, which is characterized in that it comprises one-chamber tight cylinder means, in which membrane means can slide that are connected through shaft means and mechanical means to the friction-clutch pedal or to its equivalent leverage; three-way solenoid valve means, one way of said means communicating with the chamber of said cylinder means, another way communicating with vacuum generating means while the third way communicates with venting means of said chamber of said cylinder means; one-way vent solenoid valve means arranged as a bypass across the connection between the three-way solenoid valve means and said venting means, and operatively actuated by frequency generator means; said venting means being connected, direct or indirect, to the friction-clutch pedal or to its equivalent leverage, and being operatively actuated by the carburetor of the vehicle, while the commutation of said three-way solenoid valve means is actuated through the acceleration or speeding up means of the vehicle. According to the latter embodiment of the device of the present invention, a very simple servo friction-clutch structure is advantageously obtained, as no two-chamber tight cylinder is necessary, even though both the embodiments disclosed herein allow the friction-clutch to be optimally actuated and in a way similar to that obtained through the driver's stepping on the friction-clutch pedal. Employing the second embodiment disclosed above, the friction-clutch operation is obtained by modulating or controlling the vacuum valve. According to a particularly preferred embodiment of the device of the present invention, said venting means comprise a seal or tight small piston coupled, on one side with a venting outlet and, on the other side, operatively coupled with the carburetor. Further according to the present invention, said venting means are operatively actuated through a mechanical coupling means with the throttle of said carburetor, said throttle being connected with small lever means which are in turn connected to said venting means through wire means. Again according to the present invention, said venting means can be operatively actuated by the carburetor of the vehicle providing a membrane with a mobile small piston, said membrane being connected to said carburetor at an upper position with respect to the valve of the latter, through a small hole, so that the vacuum within said carburetor causes the displacement of said mobile small piston according to the opening of said valve, which small piston, being in turn connected to said venting means, causes the consequent displacement of the same. The position at which said membrane means communicate through said small hole with said carburetor at an upper position with respect to the valve of the latter, is suggested by the fact that a constant vacuum valve which constantly changes with the opening of the valve is present in that zone, differently from what occurs at a lower position with respect to said valve, as many experiments have shown that in such zone the vacuum valve changes in a very irregular and unforeseeable way. According to a preferred embodiment of the device of the present invention, said mechanical means for connecting said membrane means, and as a consequence, said shaft means, to the friction-clutch pedal or to its equivalent leverage, are made up of a connector and of a cord which can run within a sheathing and is connected to a ball-and-socket joint. Again according to the present invention, said vacuum generating means can advantageously consist of the engine manifold of the vehicle, a check-valve or non-return valve being provided on the duct connecting said manifold with said solenoid valve means, said check-valve allowing the flow in the direction from the solenoid valve means to the manifold only. Advantageously, a vacuum reservoir can be arranged as a bypass on said duct. As already mentioned above, said venting means are advantageously connected direct or indirect to the friction-clutch pedal or to its equivalent leverage. According to a first solution to the problem, said connection is obtained providing plate means between said shaft means and said mechanical means, and said venting means. Further according to the present invention, the latter means can be connected to said shaft means through a shaft extension and shaped lever means, in particular according to the embodiment of the device of the present invention in which cylinder means are provided consisting of one only tight chamber. As an alternative, said venting means can be provided direct on the friction-clutch pedal, or on its equivalent leverage, or at any other advantageous position, as on the other hand such particular choice is of no bearing as regards the good operation of the device of the present invention, but it is only a particular choice of a constructive kind. Again according to the present invention, the commutation of said three-way solenoid valve means is actuated by an electric contact provided below the gas pedal of the motor vehicle, said contact being de-energized when the vehicle is riding at a certain number of revolutions per minute so that said frequency generator means start operating and the venting of said cylinder means occurs through said venting solenoid valve means consisting of the one-way solenoid valve. Moreover, according to the present invention said frequency generator means are connected to the tachometer of the vehicle so as to cause the operation of said one-way venting solenoid valve means at a predetermined speed value only. The present invention will be disclosed in the following for illustrative and not for limitative purposes with particular reference to some preferred embodiments of the same and with reference to their illustrations shown in the enclosed drawings, wherein: Figure 1 is a schematic view of a first embodiment of the device according to the present invention; Figures 1a and 1b show the accelerator or gas pedal of a motor vehicle respectively in the rest and the operative position; Figure 1c shows schematically the frequency generator connected to the tachometer of the motor vehicle on which the device according to the present invention is provided; Figure 2 shows a schematic view of a second embodiment of the device according to the present invention; Figure 3 shows a schematic view of a third embodiment of the device according to the present invention; Figure 4 shows a schematic view of the solenoid valve of the device according to the present invention, said valve being de-energized; Figure 5 shows a schematic view of the solenoid valve of the device according to the present invention, said valve being energized; Figure 6 shows a schematic view of the small venting piston of the device according to the present invention, in one kind of application; and Figure 7 shows a schematic view of the small venting piston of the device according to the present invention, in a second kind of application. With reference now to the embodiment shown in Figure 1, a current is sent to the electric circuit of the servo friction-clutch after inserting and rotating the ignition lock key of the motor vehicle. Said electric current, reaching the positive pole of the three-way solenoid valve 1, energizes the same causing it to commute from the position shown in Figure 4, wherein the atmospheric pressure flows in through the channel 2 and reaches said servo friction-clutch to the position shown in Figure 5 wherein the communication of the servi friction-clutch connected to the channel 4 of said solenoid valve 1 is established through the channel 3 with the vacuum. Indeed, the solenoid valve 1 is connected to a vacuum circuit consisting of the pipe 5 that is connected on one side to said channel 3 of the solenoid valve and on the other side to the vacuum source 6 which may also be made up of the manifold itseld of the motor vehicle engine. A check-valve 7 is provided on said pipe 5, such check valve allowing the air to flow in the direction from the channel 3 to the vacuum source 6 only, and not in the reversed direction. A branch 8 from the pipe 5 reaches the vacuum reservoir 9. The channel 4 of the solenoid valve 1 communicates with the chamber 10 of the servo friction-clutch cylinder. Said chamber 10 is separated from the chamber 11 by a movable membrane 12 which is integral with the shaft 13 connecting said membrane 12 through the connector 14 to the cord 15 running inside the sheathing 16, said cord 15 being connected to the spherical joint 17 that allows the friction-clutch pedal (or its equivalent leverage) to be pulled. When the solenoid valve 1 is energized, the membrane 12 is pushed toward the bottom wall of the chamber 10 as a result of the vacuum so generated. Indeed, said chamber 10 becomes evacuated whereas the atmospheric pressure will be present within chamber 11 because of the air flowing in through the non-return valve 18. That phase is now considered, the friction-clutch being disengaged and the motor vehicle being at a stop. The engagement phase of the clutch starts when a pressure is exerted on the accelerator or gas pedal, which pedal, in addition to making the carburetor throttle to rotate, also opens the electrical contact 19 (Figures 1a and 1b) which is present on the pedal itself. Said electrical contact 19 causes the solenoid valve 1 to commutate from the positon shown in Figure 5 to the position of Figure 4, so that the duct 3 is closed whereas the conduct 2 is opened again, said conduct causing the chamber 10 to communicate with the atmosphere. The action of the springs 20 pushes the membrane 12 towards the chamber 11, so that the air volume contained within the space 11 becomes compressed because air can not be vented through the check-valve 18 or through the vent piston 21. The tightness of said small piston 21 is ensured by the small cylinder that bears the seal 22 which obstructs the passage 23. The return of the membrane 11 and consequently of the small cylinder 13 is prevented under such conditions from occurring so that also the pedal (or the equivalent leverage) of the clutch will be stopped in its stroke. If the speeding up action is continued, a further opening will occur of the carburetor throttle as well as the consequent displacement of the small lever 24 which is rigidly connected to said throttle. The cable 25 is connected to said small lever 24, said cable being in turn rigidly connected to the small piston 21 so that the displacement of the lever 24 will cause it to move away from the venting point 23. According to this embodiment of the device of the present invention, said small piston 21 and said cable 25 are connected through the two plates 26 and 26' rigidly to the shaft 13 and to the cable 15. The air within the chamber 11, being vented out the opening 23, allows the membrane 12 and consequently the shaft 13, the cable 15 and the friction-clutch pedal to be displaced, so that the friction disk will further approach to the engine flywheel. The translation motion of the system which is made rigid by said plates 26 and 26' will cause the duct 23 to close again and consequently the membrane 12 to stop. All that occurs again each time the gas pedal is acted upon, so that the driver can proportion the slipping of the friction at his will in relation to the load conditions of the motor vehicle and to the number of revolutions of the engine. When the impact slipping phase of the friction-clutch is over, the motor vehicle starts riding. Each time the gas pedal is released, till the vehicle has not reached the speed of 15 km/hr (about 10 mph) the electrical contact 19 closes because of the action of the spring 27 which is present below the gas pedal (Figure 1a). When, on the contrary, the speed of 15 km/hr (about 10 mph) is surpassed, the electronic device (not shown) starts operating, which device exploits the pulses from a frequency generator 28 (Figure 1c) applied on the tachometer cord, said tachometer being pointed out by number 29. Said electronic device cuts the gas pedal contact 19 out, so that the friction-clutch is prevented from disengaging each time said gas pedal is released, and then the compression slowing down of the vehicle is kept when the speed of the vehicle decreases, said device also causing, after an electronic contact (not shown) provided for instance on the gear lever has been acted upon, said electronic contact so acted upon having determined the disengagement of the friction-clutch, the opening of the venting valve 30 and consequently the air within chamber 11 to flow out of the same so that the quick re-engagement of the friction-clutch is made possible during the shifting when the motor vehicle is riding. Each time said vehicle is slowed down till reaching a speed slower than 15 km/hr (about 10 mph) the intervention of said electronic device will not occur. Figure 2 illustrates a second embodiment of the device according to the present invention. It can be observed that chamber 11 operates with a free air flow, as no sealing or air-tight member is provided on the shaft 13. According to this kind of embodiment, the channel 2 of the solenoid valve 1, instead of being direct connected to the air intake, is connected through the pipe 31 with the venting piston 21, the one-way valve 30 being previously interposed. By means of such arrangement, when the vehicle is set going or anyway when its speed is lower than 15 km/hr (about 10 mph), the venting will occur from said small piston 21, whereas when the speed of the vehicle is faster than that value, such venting will occur as previously through said valve 30. Figure 3 illustrates a third embodiment of the present invention wherein said chamber 11 also operates with a free air circulation as in the preceeding case, but the rigid connection between the shaft 13 and the venting piston 21 is obtained in this instance through an extension shaft 32 from the membrane 12 through the chamber 10 and by a shaped lever 33 hinged at 34, and not through the plate 26 which was employed in the previous case. Indeed, in the present case the small venting piston 21 is provided behind said chamber 10 and not on the side of chamber 11. As shown schematically in Figures 6 and 7, the small venting piston 21 can be provided indifferently either on the friction-clutch leverage 25 (Figure 6) or on the friction-clutch pedal 37 (Figure 7), or also in other positions which could be considered as advantageous, instead of being connected through said plates 26 and 26' to said extension shaft 32, or to the shaft 13. The present invention has been disclosed for illustrative and not for limitative purposes with reference to some of its preferred embodiments, but it is to be understood that modification and changes can be introduced into said invention by those who are skilled in the art without departing from the spirit and scope of the invention.

Claims: 1. A servo friction-clutch device for automating the friction-clutch operation in vehicles of any kind, said device comprising cylinder means consisting of an airtight chamber, and also comprising three-way solenoid valve means, said device being characterized in that such two chambers of said cylinder means are separated by sliding membrane means which are connected through shaft means air-tight slidable through one of said chambers and by mechanical means to the friction-clutch pedal or to its equivalent leverage; and also characterized in that said three-way solenoid valve means have one of their ways connected to said cylinder means, another way being direct communicating with the atmospheric pressure, while the third way communicates with vacuum generating means, the commutation of said ways actuated by the acceleration means of the vehicle; venting means being connected to the chamber of said cylinder means in which said shaft means can slide, such venting means being operatively actuated by the carburetor of the vehicle and being connected direct or indirect to the friction-clutch pedal or to its equivalent leverage, check-valve means for air inlet into said chamber and one-way venting solenoid valve means being operatively connected to frequency generator means. 2. A servo friction-clutch device for automating the friction-clutch operation in vehicles of any kind, said device being characterized in that it comprises airtight one-chamber cylinder means in which membrane means can slide, said membrane means being connected, through shaft means and mechanical means, to the friction-clutch pedal or to its equivalent leverage; three-way solenoid valve means, one way of which being in communication with the chamber of said cylinder means, another way being in communication with vacuum generating means while the third chamber communicates with venting means of said chamber of the cylinder means; one-way venting solenoid valve means arranged as a bypass or off-take across the connection between said three-way solenoid valve means and said venting means, and operatively actuated by frequency generator means; said venting means being connected direct or indirect to the friction-clutch pedal or to its equivalent leverage and being operatively actuated by the carburetor of the vehicle, while the communication of the three-way solenoid valve means is actuated through the acceleration means of the vehicle. 3. A servo friction-clutch device according to claims 1 or 2, said device being characterized in that said venting means comprise a tight piston coupled to a venting outlet and connected on the other side operatively to the carburetor of the vehicle. 4. A servo friction-clutch device according to claims 1 or 2 and 3, said device being characterized in that said venting means are actuated by the throttle of said carburetor through small lever means which are connected to said throttle and which are linked by wire means to said venting means. 5. A servo friction-clutch device according to claims 1 or 2 and 3, said device being characterized in that said venting means are actuated by the vacuum within the carburetor, which vacuum through a small hole that is preferentially arranged at the upper part with respect to the valve of the carburetor itself, acts on a movable small piston provided inside a membrane, said piston being in turn connected to said venting means. 6. A servo friction-clutch device according to anyone of the preceeding claims, said device being characterized in that said mechanical means for connecting said membrane means and said shaft means to the clutch pedal are made up of a connector and a cord which can slide inside a sheathing and is connected to a ball-and-socket joint. 7. A servo friction-clutch device according to anyone of the preceeding claims, said device being characterized in that said vacuum generating means are made up of the manifold of the engine of said vehicle, a check-valve being provided on the duct connecting said manifold to said solenoid valve means, said check-valve allowing the flow to pass in the direction from the solenoid valve means to the manifold only. 8. A servo friction-clutch device according to claim 7, said device being characterized in that a vacuum reservoir is provided as a bypass or offtake across said duct. 9. A servo friction-clutch device according to claims 1 or 2, said device being characterized in that said venting means are connected to said shaft means and to said mechanical means through plate means. 10. A servo friction-clutch device according to claim 2, wherein said venting means are connected to said shaft means through an extension shaft and through shaped-lever means. 11. A servo friction-clutch device according to claims 1 or 2, wherein said venting means are provided direct on the friction-clutch pedal or on its equivalent leverage. 12. A servo friction-clutch device according to any one of the preceeding claims, said device being characterized in that said three-way solenoid valve means are commuted by means of an electrical contact provided below the gas pedal of the motor vehicle. 13. A servo friction-clutch device according to claims 1-12, said device being characterized in that said frequency generator means are connected to the tachometer of the vehicle so as to cause the operation of said one-way venting solenoid valve means at a pre-determined speed only. 14. A servo friction-clutch device for automating the friction-clutch operation in vehicles of any kind according to anyone of the preceeding claims and substantially as illustrated and disclosed above.

Inventors: VENTURINI, STEFANO
Applicants: VENTURINI, STEFANO
Application year: 1986
Main classification: B60K41
IPC codes: F16D48, F16H61