The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 25, 1999
Filed:
Feb. 28, 1997
Steven R Hall, Bedford, MA (US);
Eric F Prechtl, Malden, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
An actuator having two frames, each frame including a distal end member, a proximal pivot end member or proximal end pivot point, and at least two elongated side members connected between the distal end member and the proximal pivot end member of that frame. A flexure is disposed between an end of the pivot end member of the first frame and an end of the pivot end member of the second frame. A first longitudinal span member is disposed between the distal end member of the second frame and the pivot end member of the first frame, and a second longitudinal span member is disposed between the distal end member of the first frame and the pivot end member of the second frame. At least one of the first and second longitudinal span members is an expansive element having a longitudinal axis along which dimensional strain can be induced in response to an applied stimulus. This expansive element extends in a state of compression between the corresponding distal and proximal pivot end members, with the longitudinal axis of the element in a plane parallel to side members of the first and second frames. The one or both of the longitudinal span members that are expansive elements can be, e.g., a magnetostrictive element, an electrostrictive element, or a piezoelectric element. The actuator provides many of the characteristics required to achieve optimal mass efficiency for a given set of actuator materials; and further provides advantages of high bandwidth, linearity, and large stroke performance advantages. As a result, the actuator can be adapted to many applications and can accommodate a range of engineering constraints.