Jamming Methods and Apparatus

• US 20120280421A1
• Filed: 05/03/2012
• Published: 11/08/2012
• Est. Priority Date: 05/03/2011
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Keating, Steven, Oxman, Neri
• Granted Patent: US 9,764,220 B2
• Time in Patent Office: Days
• US Class Current: 264/227
• CPC Class Codes: A63C 19/04 Mats or carpets for courts
• CPC Class Codes: A63C 2203/16 Inflatable
• CPC Class Codes: E01C 13/04 Pavings made of prefabricated single units E01C13/003, E01C13/06 , E01C13/08, E01C13/10 take precedence
• CPC Class Codes: E04F 15/107 composed of several layers, e.g. sandwich panels layered products in general B32B; producing decorative panels or veneers B44C5/04
• CPC Class Codes: E04F 2290/044 against impact
• CPC Class Codes: F16B 4/002 engaging or disengaging by means of fluid pressure
• CPC Class Codes: F16B 7/00 Connections of rods or tubes, e.g. of non-circular section, mutually, including resilient connections F16B11/008, F16B17/00 take precedence; umbrella frames A45B25/02; welding or soldering of connections B23K; vehicle connections in general B60D; railway couplings B61G; bicycle frames B62K; couplings for transmitting rotation F16D; couplings for tubes conveying fluids F16L

Abstract

In exemplary implementations of this invention, a reconfigurable device comprises flexible bladder that encloses a jammable material. The geometry of the device can be altered by unjamming the jammable material (making it flexible), changing the shape of the device while it is flexible, and then jamming the jammable material (making it rigid). In some applications of this invention, a joint connects rigid arms. The ends of the rigid arms are enclosed in the bladder. By varying the stiffness of the jammable material in the bladder, the stiffness of the joint can be controlled.

Claims

1. A joint that joins two or more rigid structural members, which joint comprises, in combination:

a jammable material,

a flexible container for containing the jammable material and for containing an end of each of the structural members, respectively, and

means for changing the density of the jammable material sufficiently to vary the rigidity of the jammable material.

2. The joint of claim 1, wherein the ends are annular and interlock directly with each other.

3. The joint of claim 1, wherein the ends are annular and the joint further comprises an additional annular part that interlocks directly with each of the ends, respectively.

4. The joint of claim 1, wherein the joint further comprises a mechanical connection between the ends, which connection permits two of the structural members to be displaced relative to each other in only one direction.

5. The joint of claim 1, wherein the jammable material comprises a granular solid in a liquid.

6. The joint of claim 1, wherein the flexible container comprises an elastomer.

7. The joint of claim 1, wherein the jammable material comprises a fluid, a granular solid, and other solid components in addition to the granular solid, which other solid components have a different material composition than the granular solid.

8. A method of using an apparatus to apply a compressive force to an object, wherein:

the apparatus comprises multiple, flexible containers each of which contain jammable material,

the method comprises the following steps, in combination;

moving the containers until at least a portion of the object is in contact with at least part of each of the containers, respectively, and

increasing the rigidity of the jammable material by applying external pressure to the least two containers,

the external pressure is due, in part, to a net difference between fluid pressure within and without the containers and is due, in part, to an additional pressure, and

the compressive force arises, at least in part, from transmission of the external pressure through at least two of the multiple containers to the object.

9. The method of claim 8, wherein the additional pressure source comprises pressure from one or more solid objects pressing against one or more of the multiple containers.

10. The method of claim 8, wherein the jammable material comprises a fluid and a granular solid.

11. The method of claim 8, wherein the jammable material comprises a fluid, a granular material, and other solid components in addition to the granular solid, which other solid components have a different material composition than the granular solid.

12. A method of using a device to make a casting of a first object, wherein the device comprises a flexible material containing a jammable material, the method comprising, in combination:

reducing the density of the jammable material until the jammable material is flexible,

reducing distance between the first object and the device until at least a portion of the first object is in contact with at least part of a surface of the device,

increasing the density of the jammable material until the part of the surface becomes a rigid mold that is in the shape of a negative impression of the portion of the first object,

removing the first object from the mold,

inserting a liquid into the mold and allowing the liquid to solidify into a solid casting,

decreasing the density of the jammable material, and

removing the casting from the mold.

13. The method of claim 12, wherein the jammable material comprises solid granules in a second liquid.

14. The method of claim 12, wherein the pressure exerted by a third liquid on the exterior of the flexible material may be varied in order to change the density of the jammable material.