Patent US780060A successfully refreshed from Google Patents.
Patent US3893534A successfully refreshed from Google Patents.
US3893534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Servo aided steering system
Assignee: Robert Bosch GmbH
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Filing: 1974-02-27
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Granted: 1975-07-08
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Expires: 1994-02-27
Abstract
Abstract A torsion element such as a shaft portion of reduced diameter connects a driven steering shaft to a manually actuated steering drive shaft. A helical spring coupling connects a driving gear operated by a reversible electric motor in such a way that when the torque applied to the torsion element is at or near zero, or torque can be transmitted from the motor to the driven shaft, whereas the presence of torque causes the spring to be expanded, as a result of which the motor is coupled to the driven shaft with a frictional engagement that increases the transmission as the manually applied torque is increased. As soon as the manually applied torque falls below a threshold value, the coupling of the motor is released. The motor accordingly does not need to have its speed controlled and is operated by a simple directional control responsive to the deformation of the torsion element. The system is essentially fail-safe and accordingly suitable for steering vehicles.
Inventors
- 👤 Helmut Steinmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:09
CPC Classifications
B; B62; B62D; B62D5/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
208 words
Servo aided steeriNg system comprising: a manually actuatable driving shaft (10); a driven steering shaft (11); torsion coupling means (12) for mechanically connecting said driving and driven shafts, while allowing relative displacement therebetween dependent on direction and amount of transmitted torque; motor means (30-63) for aiding manual actuation, said motor means being responsive to the presence and direction of the first predetermined minimum amount of torque transmitted through said torsion coupling and being unenergized in the absence of said first predetermined minimum amount of torque, and second coupling means (17- 27) for coupling said motor means to said driven shaft and for releasing said motor means from said driven shaft when said torque falls below a second predetermined amount of torque, said second coupling means including a rotary element driven by said motor means coaxial with elements respectively mounted on and driving and driven shafts and including also at least one intermediate coupling element and being operable automatically by mechanical engagement and disengagement to couple and to release said motor means as aforesaid, said second predetermined amount of torque being determined by the deformability of at least one of said elements of said second coupling means in response to said relative displacement allowed by said torsion coupling means.
Claim 2
Dependent Claim
208 words
Servo aided steeriNg system comprising: a manually actuatable driving shaft (10); a driven steering shaft (11); torsion coupling means (12) for mechanically connecting said driving and driven shafts, while allowing relative displacement therebetween dependent on direction and amount of transmitted torque; motor means (30-63) for aiding manual actuation, said motor means being responsive to the presence and direction of the first predetermined minimum amount of torque transmitted through said torsion coupling and being unenergized in the absence of said first predetermined minimum amount of torque, and second coupling means (17- 27) for coupling said motor means to said driven shaft and for releasing said motor means from said driven shaft when said torque falls below a second predetermined amount of torque, said second coupling means including a rotary element driven by said motor means coaxial with elements respectively mounted on and driving and driven shafts and including also at least one intermediate coupling element and being operable automatically by mechanical engagement and disengagement to couple and to release said motor means as aforesaid, said second predetermined amount of torque being determined by the deformability of at least one of said elements of said second coupling means in response to said relative displacement allowed by said torsion coupling means.
Claim 3
Dependent Claim
189 words
Servo aided steering system as defined in claim 1 in which said second coupling means (17-27) comprises a helical spring (23) which in its quiescent condition is biased to lie against the inner wall of a bore (22) in a hub (20) or a rotary member (21) driven by said motor means and, in which further, said helical spring (23) surrounds in spaced relation a cup-shaped member (13) affixed to said driving shaft (10) and provided with a cut-out portion (15) in its peripheral wall (14), and in which, further, said helical spring (23) has bent over ends (24, 25) disposed to grasp into said cut-out (15) of said cup-shaped member (13) and in which, further, a structure (17) carrying a projecting finger (18) is fixedly mounted on said driven shaft (11), said finger (18) being disposed to project into said cut-out (15) and being dimensioned so as to have rotary play within said cut-out and to engage one or the other of said bent over ends (24, 25) of said helical spring (23) or neither of them according to the relative position of said driving and driven shafts.
Claim 4
Dependent Claim
87 words
Servo aided steering system as defined in claim 2 in which the quiescent position of said helical spring (23) the spacing (A) between said bent over ends (24, 25) of said helical spring (23) is greater than the spacing (B) between the edge (26) of said cut-out (15) of said cup-shaped member (13) and the farther edge (27) of said finger (18) and that said first mentioned spacing (A) is smaller than the dimension (C) in the circumferential direction of said cut-out (15) in said cup-shaped member.
Claim 5
Dependent Claim
39 words
Servo aided steering system as defined in claim 2 in which said finger (18) is affixed to a cylindrical casing (17) which is affixed on said driven shaft (11) for rotation therewith and surrounds said torsion coupling means (12).
Claim 6
Dependent Claim
19 words
Servo aided steering system as defined in claim 1 in which said motor means comprises an electric motor (30).
Claim 7
Dependent Claim
20 words
Servo aided steering system as defined in claim 5 in which said electric motor (30) is a permanent magnet motor.
Claim 8
Dependent Claim
27 words
Servo aided steering system as defined in claim 5 in which the deformation of said torsion coupling (12) operates as a control element for said electric motor.
References Cited (Backward Citations)
US2930247A
Cited
US3570639A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |