Walking expansion actuator

• US 5,327,038 A
• Filed: 12/16/1991
• Issued: 07/05/1994
• Est. Priority Date: 05/09/1991
• Status: Expired due to Fees

• Current Assignee: Rockwell International Corporation
• Original Assignee: Rockwell International Corporation
• Inventors: Culp, Gordon W.
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): HASZKO, DENNIS
• Application Number:
  US07/807,667
• Time in Patent Office: 932 Days
• Field of Search: 310/306, 310/307, 310/316, 310/317, 310/323, 310/328, 60/516, 60/531, 60/910, 60/911, 417/52
• US Class Current: 310/306
• CPC Class Codes: B62D 57/00 Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels or endless track sledges B62B; motor sledges B62M
• CPC Class Codes: B65G 35/005 with peristaltic propulsion along a flexible tube
• CPC Class Codes: F03G 7/06 using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like using thermal expansion of non-vaporising liquids F01K
• CPC Class Codes: Y10S 60/911 Fluid motor system incorporating electrical system

Abstract

This invention is for an object moving actuator composed of a stack of independently controllable layers which convert thermal exobaric pulses into mechanical motion. Each layer can be a lifter for moving the stack normal to the object to be moved or a tangenter for moving the stack tangentially to the object. Each layer has a plurality of chambers having a heat source and a thermal expansive material contained therein. The heat source is controlled by a controller to generate a heat pulse which expands the thermal expansive material thereby moving a rolling barrier to make the layer move normally or tangentially. Preferably two pair of actuator stacks work together to alternately engage and move the object. The first pair makes contact with the object by lifter motion and moves the object by tangenter motion while the second pair is lifted off the object and retraces to get into position to contact and translate the object. When the actuator engages the object at the same speed the object is moving so that no frictional rubbing occurs, smooth walking motion is achieved.

Claims

1. An actuator comprising:

a stationary sheet;

a translatable sheet opposite the stationary sheet;

a rolling barrier, having rolling contact with the stationary sheet and the translatable sheet, for moving one sheet relative to the other;

a fixed barrier attached to the stationary sheet, and extending to a point proximate the translatable sheet, and;

two end walls, said stationary sheet, translatable sheet, rolling barrier, fixed barrier, and end walls, forming the boundaries of a chamber;

a heat source in the chamber;

a thermoexpansive material in the chamber;

a means of activating the heat source to provide an exobaric pulse in the thermoexpansive material, which expands in the chamber, forcing the rolling barrier to translate the translatable sheet relative the stationary sheet by rolling contact with the sheets.

2. An actuator as in claim 1 wherein

said rolling barrier translates the translatable sheet parallel to the stationary sheet to form a tangenter.

3. An actuator as in claim 1 wherein

said rolling barrier translates the translatable sheet normal to the stationary sheet to form a lifter.

4. An actuator as in claim 2 wherein there is a chamber having a heat source and thermoexpansive material on both sides of the rolling barrier so that the translatable sheet is translated in opposing directions by activating the heat source on one side of the rolling barrier or the other.

5. An actuator as in claim 4 wherein there is a gap between the fixed barrier and the translatable sheet.

6. An actuator as in claim 5 wherein the rolling barrier is a cylinder.

7. An actuator as in claim 5 wherein the rolling barrier has a rectangular cross sectional shape on three sides, having two flat side portions, and a flat bottom portion, which rests on and pivots on a cylindroidally convex portion of the stationary sheet, the rolling barrier having a top portion which is cylindroidally convex for engaging the translatable sheet.

8. An actuator as in claim 5 wherein the rolling barrier and the fixed barrier are adjacent to each other, the barriers having overlapping cycloidal sealing surfaces and having cycloidic concave portions which form the chamber containing the heating source and the thermoexpansive material.

9. An actuator as in claim 3 wherein the rolling barrier comprises two bars, one disposed on top of the other, the bars having convex cylindroidal curvatures on their top and bottom surfaces, such that the sheets will be moved apart when the bars are displaced by an exobaric pulse.

10. An actuator as in claim 3 wherein the rolling barrier comprises two bars, one disposed on top of the other, the bars having convex cylindroidal curvatures on their top portions and flat bottom portions the lower of which rests on and can pivot on a cylindroidally convex portion of the stationary sheet, such that the sheets will be moved apart when the bars are displaced by an exobaric pulse.

11. An actuator as in claim 9 wherein the fixed barrier is replaced by a second rolling barrier.

12. An actuator as in claim 10 wherein the fixed barrier is replaced by a second rolling barrier.

13. An actuator as in claim 11 wherein there is a heating source and thermoexpansive material between every other rolling barrier.

14. An actuator as in claim 11 wherein there is a heating source and thermoexpansive material between every rolling barrier so that the rolling barriers are disposed in opposite directions by exobaric pulses by alternate activation of heater sources to lift or lower the translatable sheet.

15. An actuator as in claim 12 wherein there is a heating source and thermoexpansive material between every other rolling barrier.

16. An actuator as in claim 12 wherein there is a heating source and thermoexpansive material between every rolling barrier so that the rolling barriers are disposed in opposite directions by exobaric pulses by alternate activation of heater sources to lift or lower the translatable sheet.

19. An actuator as in claim 1 wherein, a plurality of actuators are layered to form an actuator stack,

where each layer comprises the stationary sheet, the translatable sheet, and the rolling barrier, the fixed barrier and heat source located between the sheets.

20. An actuator as in claim 19 where the actuator stack has at least two layers, wherein when layers are attached in the stack there is a first layer and a second layer adjacent to the first layer, where the stationary sheet of the first layer is attached to the translatable sheet of the second layer.

21. An actuator as in claim 19 where the actuator stack has at least two layers, wherein when layers are attached in the stack there is a first layer and a second layer adjacent to the first layer, where each sheet doubles as the fixed sheet of the first layer and as the translatable sheet for the second layer.

22. An actuator as in claim 19 where there is a stack of tangenters for tangential movement of an object.

23. An actuator as in claim 19 where there is a stack of lifters.

24. An actuator as in claim 19 wherein there is a stack having a first end and a second end composed of tangenter layers and lifter layers said stack attached to a housing on the first end and having a traction surface attached on the second end for engaging the surface of an object.

25. An actuator as in claim 24 wherein there are axier layers, the tangenter layers and axier layers are angled to one another.

26. An actuator as in claim 24 wherein there is a first set of at least two stacks of actuators simultaneously contacting the surface of an object to hold and move said object at any one time and a second set of at least two stacks of actuators positioned to alternately contact the surface of an object to hold and move said object when the first set is no longer in contact with the object.

27. An actuator as in claim 26 wherein the actuators move the object by smooth walking motion.

28. An actuator as in claim 1 wherein the heat source is an electrical heating element.

29. An actuator as in claim 1 wherein the heat source is a chemoelectric reaction.

30. An actuator as in claim 29 wherein catalytic coatings are used in the chamber.

31. An actuator as in claim 30 wherein there is a means of introducing chemoelectric material into the chamber and exhausting the waste product of the chemical reaction.

32. An actuator as in claim 1 wherein there are cooling channels in the sheets.

33. An actuator as in claim 24 wherein the heat source is controlled by a controller which sends electrical signals to each chamber in the layers, said signals are different for each layer such that the mechanical Fourier summing of the layers results in a predetermined desired movement of the actuator stack.

34. An actuator as in claim 33 wherein there are motion and force sensors in the actuator stack for providing information about the actuators position to the controller.

35. An actuator as in claim 2 wherein the sheets are flat.

36. An actuator as in claim 3 wherein the sheets are flat.

37. An actuator as in claim 2 wherein the sheets are curved.

38. An actuator as in claim 3 wherein the sheets are curved.

39. An actuator as in claim 22 wherein the sheets are flat.

40. An actuator as in claim 23 wherein the sheets are flat.

41. An actuator as in claim 22 wherein the sheets are curved.

42. An actuator as in claim 23 wherein the sheets are curved.

43. An actuator as in claim 19 wherein at least one layer in the stack is a piezoelectric layer.

44. An actuator as in claim 19 wherein at least one layer in the stack is an electrodeformable layer.

17. A lifter actuator comprising at least one chamber having a heat source and thermoexpansive liquid therein, said chamber comprising a stationary sheet and a translatable sheet each sheet having overlapping adjacent extensions which are insertable into each other and with the sheets form said chambers,

the heat source has a wick which is immersed in the thermoexpansive liquid, wherein a heat pulse from the heater changes the liquid to a vapor,

a means of activating the heat source to provide an exobaric pulse in the thermoexpansive liquid which expands, forcing the sheets to move apart.

18. An actuator as in claim 17 wherein the sheets have cooling channels for a cooling fluid to flow through and cool the sheet.