Patent US3833248A successfully refreshed from Google Patents.
US3833248A
Expired / Lapsed
US
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Shock-absorbing bumper arrangement
Assignee: ZF Friedrichshafen AG
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Filing: 1972-05-09
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Granted: 1974-09-03
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Expires: 1992-05-09
Abstract
Abstract Telescoping shock absorbers are arranged between the frame and bumper bar of an automotive vehicle in such a manner that the piston of each shock absorber moves inward of the cylinder under the impact of a collision, and liquid flows through a restricted passage between the compartments of the cylinder cavity to reduce the velocity of cylinder movement. If the passage is a groove in the inner cylinder wall, its flow section decreases in the direction of inward piston movement in such a manner that the force opposing the piston movement remains substantially constant even though the velocity of cylinder movement decreases. The same result can be achieved by forming the restricted passage in the piston, and biasing a valve member on the piston toward the passage closing position by a heavily prestressed cup spring or helical spring.
Inventors
- 👤 F Wossner
- 👤 G Schmitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:36
CPC Classifications
F; F16; F16F; F16F9/00; F16F9/32; F16F9/48; B; B60; B60R; B60R19/00; B60R19/02; B60R19/24; B60R19/26; B60R19/32; F16F9/06; F16F9/34; F16F9/346; F16F9/348
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
402 words
In a vehicle including a normally horizontally extending vehicle frame, supporting means for supporting said frame on a traffic surface for movement in a prEdetermined direction, bumper means offset from said frame in said direction for receiving the impact of a collision between said vehicle and another object, and shock absorbing means interposed between said frame and said bumper means for damping said impact and for transmitting the damped impact to said frame, said shock absorbing means including at least one telescoping shock absorber having a cylinder member bounding a cavity therein, a piston movably received in said cavity and dividing the same into two compartments, a liquid filling at least one of said compartments and a gas occupying a portion of the other compartment, said piston being formed with a restricted passage connecting said compartments, a piston rod member fixedly fastened to said piston and extending through said other compartment and outward of said cylinder member, and fastening means respectively fastening said members of said at least one shock absorber to said bumper means and to said frame for movement of said piston rod member inward of said cylinder member in response to said impact, whereby a damping force is exerted by said liquid on said piston member while said liquid flows through said passage from said one compartment into said other compartment during said inward movement of the piston rod member, the improvement in said shock absorber which comprises: a. first resilient means in the other one of said compartments for urging said liquid from said other compartment into said one compartment and thereby biasing said piston rod member outward of said cylinder member; b. valve means movable relative to said piston member toward and away from a passage closing position, 1. said valve means being urged away from said position thereof by liquid flowing from said one compartment to said other compartment through said passage and preventing liquid flow between said compartments when in said position; c. second resilient means biasing said valve means toward said position; and d. abutment means engaging said resilient means and holding the same under stress in all operative positions of said valve means, 1. said stress being sufficient to make the damping force exerted by said liquid on said piston rod member substantially independent from changes in the velocity of said piston rod member during said inward movement of the piston rod member.
Claim 2
Dependent Claim
402 words
In a vehicle including a normally horizontally extending vehicle frame, supporting means for supporting said frame on a traffic surface for movement in a prEdetermined direction, bumper means offset from said frame in said direction for receiving the impact of a collision between said vehicle and another object, and shock absorbing means interposed between said frame and said bumper means for damping said impact and for transmitting the damped impact to said frame, said shock absorbing means including at least one telescoping shock absorber having a cylinder member bounding a cavity therein, a piston movably received in said cavity and dividing the same into two compartments, a liquid filling at least one of said compartments and a gas occupying a portion of the other compartment, said piston being formed with a restricted passage connecting said compartments, a piston rod member fixedly fastened to said piston and extending through said other compartment and outward of said cylinder member, and fastening means respectively fastening said members of said at least one shock absorber to said bumper means and to said frame for movement of said piston rod member inward of said cylinder member in response to said impact, whereby a damping force is exerted by said liquid on said piston member while said liquid flows through said passage from said one compartment into said other compartment during said inward movement of the piston rod member, the improvement in said shock absorber which comprises: a. first resilient means in the other one of said compartments for urging said liquid from said other compartment into said one compartment and thereby biasing said piston rod member outward of said cylinder member; b. valve means movable relative to said piston member toward and away from a passage closing position, 1. said valve means being urged away from said position thereof by liquid flowing from said one compartment to said other compartment through said passage and preventing liquid flow between said compartments when in said position; c. second resilient means biasing said valve means toward said position; and d. abutment means engaging said resilient means and holding the same under stress in all operative positions of said valve means, 1. said stress being sufficient to make the damping force exerted by said liquid on said piston rod member substantially independent from changes in the velocity of said piston rod member during said inward movement of the piston rod member.
Claim 3
Dependent Claim
37 words
In a vehicle as set forth in claim 1, said bumper means including a bar member elongated transversely of said direction, and said shock absorbing means including two of said shock absorbers spaced along said bar member.
Claim 4
Dependent Claim
62 words
In a vehicle as set forth in claim 1, said fastening means including a fastening member attached to said piston rod member outside said cavity, and a protective outer shell fixedly attached to said fastening member, said shell enveloping respective portions of said piston rod member and of said cylinder member and slidably engaging an outer axial surface of said cylinder member.
Claim 5
Dependent Claim
24 words
In a vehicle as set forth in claim 1, said first resilient means including a cushion of gas under pressure higher than atmospheric pressure.
Claim 6
Dependent Claim
51 words
In a vehicle as set forth in claim 1, said second resilient means including a cup spring engaged by said abutment means and held thereby under a stress to make the spring force approximately uniform during the movement of said valve means toward and away from said position of the latter.
Claim 7
Dependent Claim
41 words
In a vehicle as set forth in claim 5, the flow section of said passage being sufficient to make said damping force substantially independent of the initial velocity of said piston member during said movement thereof relative to said cylinder member.
Claim 8
Dependent Claim
62 words
In a vehicle as set forth in claim 1, said second resilient means including a helical compression spring engaged by said abutment means and held thereby under a stress to make the change in the force of said spring during the movement of said valve means toward and away from said position of the latter a very small fractIon of said stress.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |