US4072010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermally driven piston apparatus
Assignee: Individual
•
Filing: 1976-11-10
•
Granted: 1978-02-07
•
Expires: 1996-11-10
Abstract
Abstract A closed cylinder contains a thermally driven free piston oscillating between hot and cold ends of the cylinder which ends are respectively connected to a thermal lag heating chamber and a turbine/cooling chamber. A thermal regenerator is provided within a cylinder bypass which bypasses a portion of the cylinder between hot and cold rebound chambers which include, respectively, the hot and cold ends of the cylinder. The hot rebound chamber also includes the thermal lag heating chamber. The heating chamber has sufficient thermal lag properties for substantially heating gas therein as the piston is rebounding away from the hot end of the cylinder, thereby sustaining piston oscillation. The cyclical heating and cooling of the working gas in the heating and cooling chambers and in the regenerator as the displacer piston coasts up and down within the bypass region of the cylinder between the rebound chambers produces a modulated pressure for driving the turbine via a nozzle-like conduit interposed between the cylinder and the turbine. The modulated pressure is augmented by orienting the hot end of the bypass and an inlet port of the thermal lag heating chamber so that, while the piston is coasting toward the cold end of the cylinder, gas flowing into the hot end of the cylinder via the bypass is directed into the cylinder in a stream which passes into the heating chamber inlet port and thence into the heating chamber for further heating therein while the piston is still coasting toward the cold end of the cylinder. The overall cycle of this heat engine is regenerative and may loosely be referred to as a modified Stirling cycle. The turbine or motor may drive a generator or alternator to produce electrical power. The turbine may be replaced by a different rotary motor or other fluid driven load.
Inventors
- 👤 Mark Schuman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:58
CPC Classifications
F; F02; F02G; F02G1/00; F02G1/04; F02G1/043; F02G1/0435; F02G2254/00; F02G2254/30
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
415 words
An energy converter comprising: a cylinder fitted with a free piston sized to form a sliding seal with the cylinder as the piston oscillates between and separates hot and cold ends of the cylinder; a cylinder bypass bypassing a portion of the cylinder so as to allow a compressible fluid to alternately flow back and forth between said hot and cold ends of the cylinder as the piston coasts in alternate directions between said cylinder ends; means for cooling the fluid flowing into the cold cylinder end and for heating the fluid flowing into the hot cylinder end thereby producing a cyclical fluid pressure variation utilizable for driving a load; said heating means including a heating chamber disposed outside of the bypass and communicating with the hot end of the cylinder via a heating chamber inlet conduit, said inlet conduit communicating with the hot end of the cylinder via a heating chamber inlet port defined in the hot end of the cylinder; said bypass including, in seriatim, a cold bypass port defined in said cold end of the cylinder, a hot bypass conduit, and a hot bypass port defined in the sidewall of the cylinder in said hot end of the cylinder, whereby the fluid exiting the hot end of the bypass via said hot bypass port flows into the hot end of the cylinder in a substantially defined stream during a first coasting portion of the oscillatory cycle while the piston is coasting in the bypass region of the cylinder toward the cold end of the cylinder; means for positioning and aligning said hot bypass conduit and said heating chamber inlet port with respect to each other and with respect to the hot end of the cylinder so as to augment passage of said fluid in said stream into said heating chamber via said inlet port and said inlet conduit for heating fluid in the heating chamber during said first coasting portion of the cycle; said piston during a hot rebound portion of the oscillatory cycle blocking said hot bypass port and compressing and forcing fluid from the hot end of the cylinder into said heating chamber for heating therein for expanding and driving said piston toward the cold cylinder end with a greater piston kinetic energy at the end of the hot rebound cycle portion than the kinetic energy of the piston at the beginning of the hot rebound cycle portion; and means for reversing the piston motion at the cold cylinder end.
Claim 2
Dependent Claim
415 words
An energy converter comprising: a cylinder fitted with a free piston sized to form a sliding seal with the cylinder as the piston oscillates between and separates hot and cold ends of the cylinder; a cylinder bypass bypassing a portion of the cylinder so as to allow a compressible fluid to alternately flow back and forth between said hot and cold ends of the cylinder as the piston coasts in alternate directions between said cylinder ends; means for cooling the fluid flowing into the cold cylinder end and for heating the fluid flowing into the hot cylinder end thereby producing a cyclical fluid pressure variation utilizable for driving a load; said heating means including a heating chamber disposed outside of the bypass and communicating with the hot end of the cylinder via a heating chamber inlet conduit, said inlet conduit communicating with the hot end of the cylinder via a heating chamber inlet port defined in the hot end of the cylinder; said bypass including, in seriatim, a cold bypass port defined in said cold end of the cylinder, a hot bypass conduit, and a hot bypass port defined in the sidewall of the cylinder in said hot end of the cylinder, whereby the fluid exiting the hot end of the bypass via said hot bypass port flows into the hot end of the cylinder in a substantially defined stream during a first coasting portion of the oscillatory cycle while the piston is coasting in the bypass region of the cylinder toward the cold end of the cylinder; means for positioning and aligning said hot bypass conduit and said heating chamber inlet port with respect to each other and with respect to the hot end of the cylinder so as to augment passage of said fluid in said stream into said heating chamber via said inlet port and said inlet conduit for heating fluid in the heating chamber during said first coasting portion of the cycle; said piston during a hot rebound portion of the oscillatory cycle blocking said hot bypass port and compressing and forcing fluid from the hot end of the cylinder into said heating chamber for heating therein for expanding and driving said piston toward the cold cylinder end with a greater piston kinetic energy at the end of the hot rebound cycle portion than the kinetic energy of the piston at the beginning of the hot rebound cycle portion; and means for reversing the piston motion at the cold cylinder end.
Claim 3
Dependent Claim
45 words
An energy converter as in claim 1, wherein: said bypass contains a thermal regenerator interposed between said cold bypass port and said hot bypass conduit, wherein said heating means and said cooling means each include said regenerator, said regenerator improving the efficiency of the thermocompressor.
Claim 4
Dependent Claim
25 words
An energy converter as in claim 1, wherein: said cooling means comprises means for connecting the cold end of the cylinder to a cool load.
Claim 5
Dependent Claim
30 words
The energy converter of claim 3 wherein: said load includes a fluid driven rotary motor connected to said cylinder so as to be driven by said fluid in said cylinder.
Claim 6
Dependent Claim
26 words
An energy converter as in claim 1, wherein: said cooling means comprises a cooling chamber disposed in said bypass proximate the cold end of said cylinder.
Claim 7
Dependent Claim
24 words
An energy converter as in claim 5, wherein: said bypass contains a thermal regenerator interposed between said cooling chamber and said hot bypass conduit.
Claim 8
Dependent Claim
27 words
An energy converter as in claim 1, wherein: said cold bypass port is disposed in the sidewall of the cylinder in the cold end of the cylinder.
Claim 9
Dependent Claim
40 words
An energy converter as in claim 7, further including: a load port defined in the cylinder sidewall, said load port being disposed at approximately the same longitudinal position along the length of the cylinder as is said cold bypass port.
Claim 10
Dependent Claim
38 words
An energy converter as in claim 1, wherein: said means for reversing the piston motion at the cold cylinder end includes a gaseous spring action of fluid compressed by the piston in the cold end of the cylinder.
Claim 11
Dependent Claim
27 words
An energy converter as in claim 1, wherein: said heating chamber further communicates with said hot end of said cylinder via a heating chamber outlet port means.
Claim 12
Dependent Claim
40 words
An energy converter as in claim 1, wherein: said heating chamber is designed to substantially continuously heat fluid within said heating chamber during said hot rebound cycle portion, said continuous heating providing sufficient heat energy to sustain the piston oscillation.
Claim 13
Dependent Claim
35 words
The energy converter of claim 1, wherein said cooling means comprises: a cooled load communicating with said cylinder via a load port in a wall of said cylinder in said cold end of said cylinder.
Claim 14
Dependent Claim
22 words
The energy converter of claim 12, wherein: said load port is in said cylinder side-wall in said cold end of said cylinder.
Claim 15
Dependent Claim
26 words
The energy converter of claim 1, wherein : said heating chamber further communicates with said hot end of said cylinder via a heating chamber outlet conduit.
Claim 16
Dependent Claim
34 words
The energy converter of claim 14 wherein: said outlet conduit communicates with said cylinder via a heating chamber outlet port provided in a wall of said cylinder in said hot end of said cylinder.
Claim 17
Dependent Claim
31 words
The energy converter of claim 15 wherein: said cylinder has a hot end-wall at said hot end of said cylinder; and said outlet port is located in said hot end wall.
Claim 18
Dependent Claim
56 words
The energy converter of claim 15 wherein: said outlet port and said outlet conduit are configured, positioned, and oriented with respect to said cylinder so as to reduce interference between said stream of fluid and fluid flowing from said heating chamber into said hot end of said cylinder via said outlet conduit and said outlet port.
Claim 19
Dependent Claim
56 words
The energy converter of claim 1 wherein said means for reversing said piston motion comprises: a variable volume cold rebound chamber within which fluid is compressed by said piston during a cold rebound portion of said cycle following said first coasting portion of said cycle; said cold rebound chamber including said cold end of said cylinder.
Claim 20
Dependent Claim
63 words
The energy converter of claim 1 wherein: said hot bypass conduit is oriented so that said fluid flowing into said hot end of said cylinder via said bypass during said first coasting portion of said cycle has a substantial velocity component along said cylinder axis in a direction extending from said cold end of said cylinder toward said hot end of said cylinder.
Claim 21
Dependent Claim
20 words
The energy converter of claim 1 wherein: said hot bypass conduit is directed approximately toward said heating chamber inlet port.
Claim 22
Dependent Claim
48 words
The energy converter of claim 1 wherein: said energy converter is configured so that most of said fluid forced via said bypass into said hot end of said cylinder in said stream enters and is heated in said heating chamber during said first coasting portion of said cycle.
Claim 23
Dependent Claim
50 words
The energy converter of claim 1 wherein : said energy converter is configured so that substantially all of said fluid forced via said bypass into said hot end of said cylinder in said stream enters and is heated in said heating chamber during said first coasting portion of said cycle.
Claim 24
Dependent Claim
57 words
The energy converter of claim 1 wherein: said heating chamber and said heating chamber inlet port are configured so as to readily admit fluid from said hot end of said cylinder during said hot rebound portion of said cycle and to continuously heat said admitted fluid throughout substantially all of said hot rebound portion of said cycle.
Claim 25
Dependent Claim
74 words
The energy converter of claim 1 wherein: said cold bypass port is disposed so that the side-wall of said piston traverses and blocks said cold bypass port during a cold rebound portion of said cycle following said first coasting portion of said cycle; and said means for reversing said piston motion includes compression of the fluid within said cold end of said cylinder by said piston during said cold rebound portion of said cycle.
Claim 26
Dependent Claim
21 words
The energy converter of claim 1 wherein: said free piston has a substantially uniform cross-section throughout substantially all of its length.
Claim 27
Dependent Claim
23 words
The energy converter of claim 1 wherein: said free piston has substantially all segments thereof moving together as a unit throughout said cycle.
Claim 28
Dependent Claim
28 words
The energy converter of claim 1 wherein: said heating chamber inlet port has a cross-sectional area which is greater than the cross-sectional area of said hot bypass port.
Claim 29
Dependent Claim
43 words
The energy converter of claim 1 wherein: said heating chamber communicates with said heating chamber inlet port via a heating chamber inlet conduit which has a mean flow axis which is approximately aligned with the mean flow axis of said hot bypass conduit.
Claim 30
Dependent Claim
25 words
The energy converter of claim 1 further comprising: means for conducting fluid between said cylinder and a load during said coasting portion of said cycle.
Claim 31
Dependent Claim
14 words
The energy converter of claim 1 wherein: said cylinder is a substantially closed cylinder.
Claim 32
Dependent Claim
32 words
The energy converter of claim 1 wherein: said cylinder has an end wall in said hot end of said cylinder, wherein said heating chamber inlet port is in said hot end wall.
Claim 33
Dependent Claim
29 words
The energy converter of claim 1 wherein: said heating chamber communicates with said hot end of said cylinder by means of said heating chamber port throughout the oscillatory cycle.
Claim 34
Dependent Claim
43 words
The energy converter of claim 1 wherein: said heating chamber is designed to substantially heat said fluid within said heating chamber while said piston is moving toward said cold end of said cylinder during blockage of said hot bypass port by said piston.
Claim 35
Dependent Claim
37 words
The energy converter of claim 1 wherein: said heating chamber port is in a wall of said cylinder; said heating chamber port being further from said cold end of said cylinder than is said hot bypass port.
Claim 36
Dependent Claim
51 words
The energy converter of claim 1 wherein: said heating chamber further communicates with said cylinder by means of another heating chamber port defined in a wall of said cylinder so as to augment the entry of said fluid in said stream into said heating chamber for heating therein during said coasting.
Claim 37
Dependent Claim
29 words
The energy converter of claim 35 wherein: said heating chamber ports are disposed further from said cold end of said cylinder than are any cylinder ports of said bypass.
Claim 38
Dependent Claim
29 words
The energy converter of claim 1 wherein: one of said heating chamber ports is in a hot end wall of said cylinder in said hot end of said cylinder.
Claim 39
Dependent Claim
39 words
The energy converter of claim 1 wherein: said energy converter is configured so that most of said fluid flowing in said stream flows into and thence out of said heating chamber during said first coasting portion of said cycle.
Claim 40
Dependent Claim
32 words
The energy converter of claim 1 wherein: said piston has a sidewall which traverses and covers said hot bypass port during said hot rebound cycle portion so as to accomplish said blocking.
Claim 41
Dependent Claim
28 words
The energy converter of claim 1 wherein: said hot bypass port, said heating chamber inlet port, and the axis of said cylinder are all in the same plane.
Claim 42
Dependent Claim
47 words
An energy converter as in claim 1, further including: a load port defined in a wall of the cylinder in said cold cylinder end, said load port being disposed at approximately the same longitudinal position along the length of the cylinder as is said cold bypass port.
Claim 43
Dependent Claim
413 words
An energy converter comprising: a cylinder fitted with a free piston sized to form a sliding seal with the cylinder as the piston oscillates between and separates hot and cold ends of the cylinder; a cylinder bypass bypassing a portion of the cylinder so as to allow a compressible fluid to alternately flow back and forth between said hot and cold ends of the cylinder as the piston moves in alternate directions between said cylinder ends; means for cooling the fluid flowing into the cold cylinder end and for heating the fluid flowing into the hot cylinder end thereby producing a cyclical fluid pressure variation utilizable for driving a load; said heating means including a heating chamber disposed outside of the bypass and communicating with the hot end of the cylinder via a heating chamber inlet conduit, said inlet conduit communicating with the hot end of the cylinder via a heating chamber inlet port defined in the hot end of the cylinder; said bypass including, in seriatim, a cold bypass port defined in said cold end of the cylinder, a hot bypass conduit, and a hot bypass port defined in the sidewall of the cylinder in said hot end of the cylinder, whereby the fluid exiting the hot end of the bypass via said hot bypass port flows into the hot end of the cylinder in a substantially defined stream during a first portion of the oscillatory cycle while the piston is moving in the bypass region of the cylinder toward the cold end of the cylinder; means for positioning and aligning said hot bypass conduit and said heating chamber inlet port with respect to each other and with respect to the hot end of the cylinder so as to augment passage of said fluid in said stream into said heating chamber via said inlet port and said inlet conduit for heating fluid in the heating chamber during said first portion of the cycle; said piston during a hot rebound portion of the oscillatory cycle blocking said hot bypass port and compressing and forcing fluid from the hot end of the cylinder into said heating chamber for heating therein for expanding and driving said piston toward the cold cylinder end with a greater piston kinetic energy at the end of the hot rebound cycle portion than the kinetic energy of the piston at the beginning of the hot rebound cycle portion; and means for reversing the piston motion at the cold cylinder end.
Claim 44
Dependent Claim
413 words
An energy converter comprising: a cylinder fitted with a free piston sized to form a sliding seal with the cylinder as the piston oscillates between and separates hot and cold ends of the cylinder; a cylinder bypass bypassing a portion of the cylinder so as to allow a compressible fluid to alternately flow back and forth between said hot and cold ends of the cylinder as the piston moves in alternate directions between said cylinder ends; means for cooling the fluid flowing into the cold cylinder end and for heating the fluid flowing into the hot cylinder end thereby producing a cyclical fluid pressure variation utilizable for driving a load; said heating means including a heating chamber disposed outside of the bypass and communicating with the hot end of the cylinder via a heating chamber inlet conduit, said inlet conduit communicating with the hot end of the cylinder via a heating chamber inlet port defined in the hot end of the cylinder; said bypass including, in seriatim, a cold bypass port defined in said cold end of the cylinder, a hot bypass conduit, and a hot bypass port defined in the sidewall of the cylinder in said hot end of the cylinder, whereby the fluid exiting the hot end of the bypass via said hot bypass port flows into the hot end of the cylinder in a substantially defined stream during a first portion of the oscillatory cycle while the piston is moving in the bypass region of the cylinder toward the cold end of the cylinder; means for positioning and aligning said hot bypass conduit and said heating chamber inlet port with respect to each other and with respect to the hot end of the cylinder so as to augment passage of said fluid in said stream into said heating chamber via said inlet port and said inlet conduit for heating fluid in the heating chamber during said first portion of the cycle; said piston during a hot rebound portion of the oscillatory cycle blocking said hot bypass port and compressing and forcing fluid from the hot end of the cylinder into said heating chamber for heating therein for expanding and driving said piston toward the cold cylinder end with a greater piston kinetic energy at the end of the hot rebound cycle portion than the kinetic energy of the piston at the beginning of the hot rebound cycle portion; and means for reversing the piston motion at the cold cylinder end.
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) | 1981-02-06 | 1981-08-08 | 1982-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-06 | 1985-08-08 | 1986-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-06 | 1989-08-08 | 1990-02-07 | $7700.00 | Window Closed / Lapsed |