US3653298A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reciprocating fluid motor having a variable drive piston area
Assignee: Chicago Pneumatic Tool Co LLC
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Filing: 1970-06-03
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Granted: 1972-04-04
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Expires: 1990-06-03
Abstract
Abstract A reciprocating motor having a piston rod upon which a group of piston sleeves varying in length is hydraulically actuable against a shoulder of the rod to drive the rod in one direction. Arresting structure is provided to cause the sleeves to become successively arrested in their driving movement so that an initial large area of the combined sleeves which is subjected to the driving fluid is progressively decreased during the stroke. A second similar group of sleeves is similarly operable to return the piston. A separate re-setting element is arranged to automatically reset each group of sleeves to a driving condition preparatory to effecting the next driving stroke of the rod, and to also cushion overtravel of the rod. The rod is cooperably during its stroke with valve elements to cause automatic hydraulic feed alternately to each group of sleeves.
Inventors
- 👤 Paul J Bilodeau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:28
CPC Classifications
F; F16; F16J; F16J1/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
232 words
In an hydraulic motor including a piston cylinder, a piston rod reciprocable axially of the cylinder having an annular radial shoulder between its ends, a first group of hydraulically actuable nested piston sleeves arranged coaxially one upon the other on the piston rod to one side of the shoulder in a first piston sleeve chamber defined at one end of the cylinder, the sleeves having when hydraulically actuated cooperation with the shoulder to drive the piston rod in one direction, a second similar group of sleeves similarly arranged upon the piston rod to the other side of the shoulder in a second piston sleeve chamber defined at the opposite end of the cylinder, the second group of sleeves having when hydraulically actuated cooperation with the shoulder to drive the piston rod in the opposite direction, means for feeding hydraulic pressure fluid alternately to the first and second chambers for actuating the sleeves therein, means in each of the chambers for determining the extent of driving cooperation of each of the sleeves therein with the shoulder, and means for draining spent hydraulic pressure fluid alternately from the first and second chambers; wherein a chamber is defined centrally of the piston cylinder between the inner ends of both groups of sleeves in which chamber the shoulder of the piston rod is carried as the piston rod is driven from one direction to the other.
Claim 2
Dependent Claim
232 words
In an hydraulic motor including a piston cylinder, a piston rod reciprocable axially of the cylinder having an annular radial shoulder between its ends, a first group of hydraulically actuable nested piston sleeves arranged coaxially one upon the other on the piston rod to one side of the shoulder in a first piston sleeve chamber defined at one end of the cylinder, the sleeves having when hydraulically actuated cooperation with the shoulder to drive the piston rod in one direction, a second similar group of sleeves similarly arranged upon the piston rod to the other side of the shoulder in a second piston sleeve chamber defined at the opposite end of the cylinder, the second group of sleeves having when hydraulically actuated cooperation with the shoulder to drive the piston rod in the opposite direction, means for feeding hydraulic pressure fluid alternately to the first and second chambers for actuating the sleeves therein, means in each of the chambers for determining the extent of driving cooperation of each of the sleeves therein with the shoulder, and means for draining spent hydraulic pressure fluid alternately from the first and second chambers; wherein a chamber is defined centrally of the piston cylinder between the inner ends of both groups of sleeves in which chamber the shoulder of the piston rod is carried as the piston rod is driven from one direction to the other.
Claim 3
Dependent Claim
44 words
In an hydraulic motOr as in claim 1, wherein the central chamber is connected at all times with a drain conduit so that pressure fluid that might leak from the first and second chambers past the first and second groups of sleeves may escape.
Claim 4
Dependent Claim
46 words
In an hydraulic motor as in claim 2, wherein a sleeve valve is axially shiftable in one direction so as to connect the first of the piston sleeve chambers with a hydraulic pressure fluid feed line and simultaneously connect the second chamber with the drain conduit.
Claim 5
Dependent Claim
43 words
In an hydraulic motor as in claim 3, wherein the sleeve valve is axially shiftable in an opposite direction so as to connect the first piston sleeve chamber with the drain conduit and to simultaneously connect the second chamber with the feed line.
Claim 6
Dependent Claim
55 words
In an hydraulic motor as in claim 4, wherein the sleeve valve has a mid-point shifted position in which the first piston sleeve chamber is connected to both the drain conduit and to the feed line, and in which the second chamber is also connected to both the drain conduit and to the feed line.
Claim 7
Dependent Claim
62 words
In an hydraulic motor as in claim 5, wherein a first pilot valve means is provided at one end of the piston cylinder for causing hydraulic shifting of the sleeve valve in one direction and a second pilot valve means is provided at an opposite end of the piston cylinder for causing hydraulic shifting of the sleeve valve in the opposite direction.
Claim 8
Dependent Claim
80 words
In an hydraulic motor as in claim 6, wherein the first pilot valve means has a normal position under the bias of a return spring in which a corresponding end of the sleeve valve is in communication through the first pilot valve means with the drain conduit, and has a shifted position against the bias of the spring in which the said corresponding end of the sleeve valve is in communication through the first pilot valve with the feed line.
Claim 9
Dependent Claim
65 words
In an hydraulic motor as in claim 7, wherein the second pilot valve means has a similar normal position under the bias of a separate return spring similarly connecting a corresponding end of the sleeve valve with the drain conduit, and has a similar shifted position against the bias of its spring connecting its said corresponding end of the sleeve valve with the feed line.
Claim 10
Dependent Claim
94 words
In an hydraulic motor as in claim 8, wherein the piston rod carries at an end portion thereof a trip ring having upon a predetermined movement of the piston rod in one direction engagement with the first pilot valve so as to shift the latter from its normal position; and the piston rod carries at an opposite end portion thereof a second trip ring having upon a predetermined movement of the piston rod in an opposite direction engagement with the second pilot valve so as to shift the latter away from its normal position.
Claim 11
Dependent Claim
56 words
In an hydraulic motor as in claim 9, wherein the innermost sleeve in each group is greater in length than the others and is biased in abutment with a corresponding side of the shoulder by means of a separate spring, the spring being limited between an end of the related sleeve and the related trip ring.
Claim 12
Dependent Claim
69 words
In an hydraulic motor as in claim 10, wherein the sleeves in one group are adapted to be carried along with the related longest sleeve during movement of the piston rod in the direction of said one group, and means is provided in the related piston sleeve chamber of said one group for arresting in sequence the extent of carried movement of each sleeve of the said one group.
Claim 13
Dependent Claim
190 words
An hydraulic piston motor including a piston cylinder, a piston rod reciprocable axially of the cylinder carrying a peripheral shoulder between its ends, a first expansible piston chamber defined to one side of the shoulder, a second expansible piston chamber defined to the other side of the shoulder, a first group of hydraulically actuable piston sleeves in the first chamber having when actuated cooperation with the shoulder to drive the piston rod in one direction, a second group of hydraulically actuable piston sleeves in the second chamber having when actuated cooperatIon with the shoulder to drive the piston rod in the opposite direction, valving means for causing feeding of hydraulic pressure fluid alternately to the piston chambers for actuating the piston sleeves therein, and abutment means in each piston chamber determining in sequential order the extent of driving cooperation of each of the sleeves therein with the shoulder; wherein a chamber is defined centrally of the piston cylinder between the inner ends of both groups of sleeves in which chamber the shoulder of the piston rod is carried as the piston rod is driven from one direction to the other.
Claim 14
Dependent Claim
190 words
An hydraulic piston motor including a piston cylinder, a piston rod reciprocable axially of the cylinder carrying a peripheral shoulder between its ends, a first expansible piston chamber defined to one side of the shoulder, a second expansible piston chamber defined to the other side of the shoulder, a first group of hydraulically actuable piston sleeves in the first chamber having when actuated cooperation with the shoulder to drive the piston rod in one direction, a second group of hydraulically actuable piston sleeves in the second chamber having when actuated cooperatIon with the shoulder to drive the piston rod in the opposite direction, valving means for causing feeding of hydraulic pressure fluid alternately to the piston chambers for actuating the piston sleeves therein, and abutment means in each piston chamber determining in sequential order the extent of driving cooperation of each of the sleeves therein with the shoulder; wherein a chamber is defined centrally of the piston cylinder between the inner ends of both groups of sleeves in which chamber the shoulder of the piston rod is carried as the piston rod is driven from one direction to the other.
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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) | 1975-04-04 | 1975-10-04 | 1976-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-04 | 1979-10-04 | 1980-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-04 | 1983-10-04 | 1984-04-04 | $7700.00 | Window Closed / Lapsed |