GB2181217A

GB2181217A - Force applying system

Info

Publication number: GB2181217A
Application number: GB08617737A
Authority: GB
Inventors: Gerhard Wirmsberger
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-07-23
Filing date: 1986-07-21
Publication date: 1987-04-15
Also published as: DE3624584A1; SE8603190D0; JPS6223855A; FR2590049A1; DK347286D0; GB8617737D0; EP0213112A1

Description

Device at applying of a force The invention relates to a deviceforthe application of a force, especially such one, which is effected by the useoffootforce, preferably on a lever. According to the state of art the lever actuated by footforce, normally called brake pedal lever, of a brake application device has only one point of impact with regard to the connection, e.g. piston rod, to the piston of the cylinder actuated by it, e.g. of the brake master cylinder of a brake application device. In other words, the point of impact of said lever on the mentioned connection is restricted to a certain spot, which can move within certain limits, as stated in the Austrian application 1517/85 of Mai 21,1985. The transmission ratio of the lever arm acting on the piston of the brake master cylinder, onto which the brake pedal force extends, is therefore mainly determined by the idle way caused by the slack of the brake. The invention is therefore intended to provide a device, which comprises at least two devices, which put different pressure steps in a cylinder, e.g. the brake master cylinder, when actuating the brake pedal lever. According to the invention it is suggested to create a device, which comprises at leasttwo different devices, from which different conditions with regard to force and/orwayon the piston of said cylinderwork. Furthermore according to the invention it is suggested to provide at least one further point of impact on said lever, which also acts on said connection, whereby said points of impact preferably have different distances with regard to the center of motion and/orthe support point of said lever. In a further embodiment of the invention a device is provided, by which said connection can be changed in its acting length, which device can be actuated from at least one of said points of impact. Further details of the invention are given in thefollowing description, which is explained by drawings, whereby Figure 1 shows a schematic drawing according to the invention, while Figure 2 shows a section according to A-A of Figure 1 of it and Figures 3, 4gives further explanations. Referring to Figure 1 of the Austrian patent application 1517/85 of May 21,1985 in the brake master cylinder 3 of a piston 2 is guided, whereby one piston rod 1 is kept by guides 4, 5, which shows an outside thread 10, that means preferably executed si milarto a spindle. The outside thread 10 gears into respective elevations 12 of sleeve 13, which therewith can be twisted against piston rod 1. A lever6 provided with brake pedal 7 is recessed in the area of piston rod 1, which meansthatthe piston rod goes through brake pedal lever 6, which is shown in Figure 2. Lever 6 is guided with the support bodies 14,15, which are tightly connected with the convenient part of the vehicle. Furthermore lever6 hasaccordingto Figure 1 and 2 a recess 16, on which sleeve 13 bites in when actuating the brake and by which sleeve 13 is hindered to turn, what also can be effected by guide 4, which can be arranged on the outside around sleeve 13. Piston rod 1 has gear 18 on its left, tapered end, bywhich it can be moved by a steering rack 19, as it is connected with a piston 20 of hydrauliccylinder 21. In cylinder 21 also piston 22 is guided, which can be moved from a piston rod 23 overan angled lever arm 24 of the brake pedal lever 6. When actuating the brake by application of force on brake pedal 7, the lower lever arm of lever 6 is moved to the left overturning point9. Resulting from that, lever arm 24 presses piston rod 23 and with that the two pistons 22 and 20 as well as gear strip 19 upwards,wherebythegears 18ofpiston rod 1 are moved, whereby according to the outside thread 10 and mountings 12, piston rod 1 istracked in direction to cylinder 3, which means to the right. As can be seen, piston rod 1 is in the same period of time moved more than lever 6 in the area of piston rod 1 and/or lever 13, assumed a correct dimensioning of the respective parts. In otherwords according to the invention the piston rod is moved faster in direction to cylinder 3 than the lever in said area when actuating the brake. The other way round, theforce acting on piston rod 1 by parts 19 to 24 is much lower than the force from lever 6 on sleeve 13 respectively piston rod 1 in said area, which means that at using up the air-slack of the brake, sleeve 13 is fully impacted with the force of lever 6, which in the area of sleeve 13 admits a greattransmission. According to the invention also the air-slack of the brake is surmounted by a much lowertransmission respectively at more motion with a lot of hydraulic fluid asthe pressing of the brake lining carrier, from which results that according to the invention the arm used for applying the brake force of lever 6 can be kept smaller, which permitsagreatertransmissionof the brake pedal force. Instead of cylinder 21 also rods can be used. Figure 3 shows the deflection levers 25 and 26 with the turning points 27 and 28 which are mounted on the convenient part of the vehicle, whereby lever 25 presses on the correctly guided gear strip 19 by moving it, when at actuating the brake the lever 6 moves to the left. Eventually a spring 29 can be adjusted as elastic link, the air-slack of which is used up when after equalising the slack of the brake, lever 6 is further actuated, but without guiding the piston rod further through toothed rack 19. In this case there is the risk of fracture, which is counteracted with what is also valid forthe execution according to Figure 1. Furthermore instead of cylinder 21 a cylinder with low pressure can be used and the piston of which is actuated by lever 6, as shown in Figure 4. In off-position of the brake a shutter 38 of a valve 33 of a low-pressure cylinder 30 keeps its boring 34 closed by a spring 36 and a shutter 29 of a valve 34 keeps its boring open. A valve rod 37 is mounted on spring 36, whereby it and the shutter are drawn down, what is also effected by spring 40 at shutter 39. By with the steam cone of the motor of the vehicle connected ducts 31 and 32, low pressure in cylinder 30 is produced, while valve 33 regulates the connec- tion from cylinder 30 to the outside air. When actuating the brake, lever arm 24 presses on springs 36 and 40, whereby shutter 38 is lifted from the boring of the low-pressure cylinder 30 respectivelyshutter39 is pressed on its boring. The outside airtherefore streams through valve 33 into cylinders 30 and acts on piston 41, as duct 31 is closed by shutter 39. A piston 41 is, resulting from that, moved upwards against a readjusting spring 42, whereby the toothed rack 19 is moved againstthe gears 18 of piston rod 1.Atfinishing of the braking operation the lever arm 24 does not put anyforce on springs 36 and 40, whereby the shutter 38 again locks its boring and locker 39 releases its boring, whereby piston 41 goes down through the readjusting spring 42. The invention was explained by means of a brake actuating device, but it can also be used for other purposes, e.g. for a coupling.

Claims

1. Deviceforapplicationofaforce,especiallyof such one, which is marked by the use offootforce, preferably on a lever, characterized by the factthatat respectively by application offootforce at least two devices (sleeve 14, gear rod 19) are available, the effect of which on the medium, e.g. hydraulic fluid in a cylinder (3) a force is put on the medium, which is differently strong with regard to the force respectivelythe amount of the moved medium whereby the amount of the moved medium and the force of two devices (sleeve 14, gear rod 19) put on it are in a different relation.

2. Device according to claim 1, characterized by thefactthatfrom said lever (6) on at leasttwo of its spots an application of force on the said medium takes place.

3. Device according to claim 1 or/and 2, characterized by the fact that between lever (6) and the piston of cylinder (3) with said medium in it, there is a connection (sleeve 13, piston rod 1), which can be changed in its effective length.

4. Device according to claim 1, characterized by the fact that one of said devices consists of a lever(6) and a sleeve (13) actuated by this lever.

5. Device according to claim 1, characterized by the fact, that one of said devices consists of a lever (6), a hydraulic cylinder (20) and a toothed rack (19).

6. Device according to claim 4 or/and 5, characterized by the fact that the connection (piston rod 1, sleeve 13) consists of at leasttwo parts (piston rod 1, sleeve 13) adjustable into each other and can be actuated from at least one of said devices.

7. Device according to one or more of above claims 1 - 6 characterized by the use of a brake actuating device (hydraulic cylinder 3) or at a coupling.