US3915064A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid drive means
Assignee: Denver Equipment Co
•
Filing: 1974-03-01
•
Granted: 1975-10-28
•
Expires: 1994-03-01
Abstract
Abstract A fluid drive device for high torque, low speed applications.
Inventors
- 👤 Tibor Dancs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:07
CPC Classifications
F; F15; F15B; F15B15/00; F15B15/02; F15B15/06; F15B15/061; F03; F03C; F03C1/00; F03C1/02; F03C1/04; F03C1/053; F03C1/0531
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
150 words
A hydraulic driving system for imparting a rotary motion to a rotary load comprising: a body member; a driving ring adapted to be drivingly connected to such a rotary load; said driving ring including a plurality of circumferentially spaced driving portions thereon; a plurality of elongated intermittently acting hydraulically actuated piston assemblies carried by said body member and each having reciprocable extensible portions which are drivingly engageable with selective ones of said driving portions throughout at least a portion of the extension thereof; valve means adapted to communicate with a hydraulic fluid pressure source and operative to control the flow of fluid from such a source to said piston assemblies to provide sequential extension and retraction of said extensible portions; and at least one of said piston assemblies including camming means thereon which are cooperable with selective ones of said driving portions to control the operation of said valve means.
Claim 2
Dependent Claim
150 words
A hydraulic driving system for imparting a rotary motion to a rotary load comprising: a body member; a driving ring adapted to be drivingly connected to such a rotary load; said driving ring including a plurality of circumferentially spaced driving portions thereon; a plurality of elongated intermittently acting hydraulically actuated piston assemblies carried by said body member and each having reciprocable extensible portions which are drivingly engageable with selective ones of said driving portions throughout at least a portion of the extension thereof; valve means adapted to communicate with a hydraulic fluid pressure source and operative to control the flow of fluid from such a source to said piston assemblies to provide sequential extension and retraction of said extensible portions; and at least one of said piston assemblies including camming means thereon which are cooperable with selective ones of said driving portions to control the operation of said valve means.
Claim 3
Dependent Claim
20 words
A hydraulic driving system as specified in claim 1 wherein said camming means are carried solely by said extensible portion.
Claim 4
Dependent Claim
46 words
A hydraulic driving system as specified in claim 1 wherein each of said piston assemblies is pivotally mounted to said body member adjacent one end thereof opposite said extensible portions and said extensible portions extend generally tangentially with respect to the periphery of said driving ring.
Claim 5
Dependent Claim
81 words
A hydraulic driving system as specified in claim 3 wherein during at least a major portion of the retraction stroke of said extensible portion of said at least one of said piston assemblies said selective ones of said driving portions engages a portion of said camming means on the inner longitudinal side of said extensible portion to cause said at least one of said piston assemblies to pivot outwardly from the periphery of said driving ring about said one end thereof.
Claim 6
Dependent Claim
69 words
A hydraulic driving system as specified in claim 4 wherein during at least a major portion of the retraction of said extensible portion of said at least one of said piston assemblies a portion of said camming means on the other longitudinal side of said extensible portion engages said valve means to cause said valve means to maintain pressure fluid flowing to the retract side of said piston assemblies.
Claim 7
Dependent Claim
70 words
A hydraulic driving system as specified in claim 1 wherein at the end of the extension stroke of said extensible portion of said at least one of said piston assemblies, the driving portion being driven by said extensible portion operatively engages said valve means to cause said valve means to channel pressure fluid to the retract side of said piston assemblies and initiate a retraction stroke of said extensible portion.
Claim 8
Dependent Claim
94 words
A hydraulic driving system as specified in claim 3 wherein said piston assemblies are pivotally connected to said body member by respective pivot assemblies each comprising: an elastomeric member rigidly secured to said one end; a cup-shaped retaining member rigidly secured to said body member and said elastomeric member; and the inner periphery of said retaining member conforms to the outer periphery of said elastomeric member in a manner that at least the major portion of said outer periphery engages said inner periphery when said elastomeric member is rigidly secured to said body member.
Claim 9
Independent Claim
138 words
A method of operating a piston assembly which has a reciprocable extensible portion thereof selectively drivingly engaging circumferentially spaced engageable portions of a driving ring which is drivingly connected to a rotary load to apply a rotary motion thereto comprising the steps of: extending said extensible portion by supplying a hydraulic pressure fluid to the extension side of said piston assembly; simultaneously with said extending, drivingly engaging a selective one of said engageable portions with the free end of said extensible portion throughout at least the major portion of said extending; at the termination of said extending, said extensible portion engaging a valve means in cooperation with said selective one of said engageable portions to cause the supply of hydraulic pressure fluid to be supplied to the retraction side of said piston assembly to retract said extensible portion.
Claim 10
Independent Claim
138 words
A method of operating a piston assembly which has a reciprocable extensible portion thereof selectively drivingly engaging circumferentially spaced engageable portions of a driving ring which is drivingly connected to a rotary load to apply a rotary motion thereto comprising the steps of: extending said extensible portion by supplying a hydraulic pressure fluid to the extension side of said piston assembly; simultaneously with said extending, drivingly engaging a selective one of said engageable portions with the free end of said extensible portion throughout at least the major portion of said extending; at the termination of said extending, said extensible portion engaging a valve means in cooperation with said selective one of said engageable portions to cause the supply of hydraulic pressure fluid to be supplied to the retraction side of said piston assembly to retract said extensible portion.
Claim 11
Dependent Claim
39 words
A method of operating a piston assembly as specified in claim 8 including the additional step of: retracting said extensible portion from the extended position thereof by supplying hydraulic pressure fluid to the retraction side of said piston assembly.
Claim 12
Dependent Claim
43 words
A method of operating a piston assembly as specified in claim 9 including the additional step of: simultaneously with said retracting engaging said valve means with said extensible portion to maintain the flow of hydraulic fluid to said retract side throughout said retracting.
Claim 13
Dependent Claim
34 words
A method of operating a piston assembly as specified in claim 10 wherein said last mentioned engaging is maintained by biasing said extensible portion outwardly with respect to the periphery of said driving ring.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |