Linear actuator

Abstract

A linear actuator is configured to provide the moving force for adjustable furniture, such as beds, chairs, or tables. The linear actuator includes a drive assembly, rigid arm, and linkage assembly. The rigid arm includes a pusher block with one or more attachment projections where the linkage assembly is attached.

That which is claimed: 
     
         1 . An arm assembly for a linear actuator for adjustable furniture, the arm assembly comprising:
 a rigid arm;   a threaded spindle extending along a threaded spindle axis; and   a pusher block comprising:
 a pusher block body comprising:
 a rigid arm passage, wherein the rigid arm extends through the rigid arm passage such that the pusher block is movable along the rigid arm; and 
 a spindle passage vertically offset, and physically separated, from the rigid arm passage, wherein the threaded spindle extends through the spindle passage; and 
 
 two attachment arms extending from the pusher block body, the attachment arms defining a linkage channel therebetween and at least one securing aperture, 
   wherein the at least one securing aperture extends along a securing aperture axis,   wherein the securing aperture axis extends transversely to the threaded spindle axis and is vertically offset from the threaded spindle axis such that the securing aperture axis does not intersect the threaded spindle axis, and   wherein the linkage channel is configured to receive an end of a linkage.   
     
     
         2 . The arm assembly of  claim 1 , further comprising:
 the linkage comprising the end, wherein the linkage is pivotally connected to the pusher block at a position that is vertically offset from the threaded spindle axis; and   a drive assembly configured to rotate the threaded spindle such that the pusher block moves along the rigid arm.   
     
     
         3 . The arm assembly of  claim 1 , wherein the pusher block body comprises a top surface and at least one side surface extending downwardly from the top surface and wherein each of the two attachment arms extends from at least one of the top surface and the at least one side surface of the pusher block body. 
     
     
         4 . The arm assembly of  claim 1 , further comprising a single fastener removably positioned within the at least one securing aperture and configured to engage the end of the linkage to pivotally connect the linkage to the pusher block. 
     
     
         5 . The arm assembly of  claim 4 , wherein the at least one securing aperture comprises two securing apertures, each extending along the securing aperture axis and wherein the single fastener extends through the two securing apertures. 
     
     
         6 . The arm assembly of  claim 1 , wherein the securing aperture axis is vertically offset above the threaded spindle axis. 
     
     
         7 . The arm assembly of  claim 1 , wherein the pusher block body and the two attachment arms are formed integrally. 
     
     
         8 . An arm assembly for a linear actuator for adjustable furniture, the arm assembly comprising:
 a rigid arm;   a threaded spindle extending along a threaded spindle axis;   a pusher block comprising:
 a pusher block body comprising:
 a rigid arm passage, wherein the rigid arm extends through the rigid arm passage such that the pusher block is movable along the rigid arm; and 
 a spindle passage vertically offset, and physically separated, from the rigid arm passage, wherein the threaded spindle extends through the spindle passage; and 
 two attachment arms extending from the pusher block body, the attachment arms defining a linkage channel therebetween and two securing apertures extending along a securing aperture axis, wherein the securing aperture axis extends transversely to the threaded spindle axis and is vertically offset from the threaded spindle axis such that the securing aperture axis and the threaded spindle axis do not intersect; and 
 
   a single fastener extending through the two securing apertures and configured to engage an end of a linkage such that the end of the linkage is pivotally connected to the pusher block solely through the single fastener and such that a connection between the end of the linkage and the pusher block is vertically offset from the threaded spindle axis.   
     
     
         9 . The arm assembly of  claim 8 , wherein the pusher block body and the two attachment arms are formed integrally. 
     
     
         10 . The arm assembly of  claim 8 , further comprising:
 the linkage, wherein the linkage is configured to attach to a piece of adjustable furniture and comprises a first end and a second end, wherein the single fastener extends through the first end such that the linkage is pivotally connected to the pusher block solely through the single fastener; and   a drive assembly configured to rotate the threaded spindle such that the pusher block moves along the rigid arm.   
     
     
         11 . The linear actuator of  claim 8 , wherein the single fastener is a clevis pin. 
     
     
         12 . The arm assembly of  claim 8 , wherein the pusher block body and the two attachment arms are formed integrally. 
     
     
         13 . A pusher block for an arm assembly for a linear actuator for adjustable furniture, the pusher block comprising:
 a pusher block body comprising:
 a first end; 
 a second end opposite the first end; 
 a rigid arm passage extending through the pusher block body from the first end to the second end, wherein the rigid arm passage is configured to receive a rigid arm of the linear actuator through the rigid arm passage such that the pusher block is slidable along the rigid arm; and 
 a spindle passage extending through the pusher block body from the first end to the second end, wherein the spindle passage extends along a spindle axis and is configured to receive a spindle of the linear actuator, and wherein the spindle passage is vertically offset and physically separated from the rigid arm passage; 
   two attachment arms extending from the pusher block body and defining at least one securing aperture extending along a securing aperture axis, wherein the securing aperture axis extends transversely to the spindle axis and is vertically offset from the spindle axis such that the securing aperture axis and the spindle axis do not intersect; and   a fastener removably positioned within the at least one securing aperture, wherein the fastener is configured to pivotally connect the pusher block with a first end of a linkage.   
     
     
         14 . The pusher block of  claim 13 , wherein the pusher block body and the two attachment arms are formed integrally. 
     
     
         15 . The pusher block of  claim 13 , wherein the at least one securing aperture comprises two securing apertures, each extending along the securing aperture axis, and wherein the fastener comprises a single fastener positioned within the two securing apertures. 
     
     
         16 . An arm assembly for a linear actuator for adjustable furniture, the arm assembly comprising:
 a rigid arm;   a threaded spindle extending along a threaded spindle axis;   a pusher block comprising:
 a pusher block body comprising:
 a spindle nut threadably engaged with the threaded spindle; and 
 a rigid arm passage, wherein the rigid arm extends through the rigid arm passage such that the pusher block body is slidable along the rigid arm; and 
 
 two attachment arms extending from the pusher block body and defining a linkage channel and a securing aperture, 
   wherein the securing aperture extends transversely to the linkage channel and is in communication with the linkage channel,   wherein the securing aperture extends along a securing aperture axis,   wherein the securing aperture axis is vertically offset from the threaded spindle axis, and   wherein the linkage channel is configured to receive an end of a linkage within the linkage channel.   
     
     
         17 . The arm assembly of  claim 16 , wherein an outer surface of the pusher block body comprises a top surface and at least one side surface extending downwardly from the top surface, and wherein the two attachment arms extend outwardly from at least one of the top surface and the at least one side surface of the pusher block body. 
     
     
         18 . The arm assembly of  claim 16 , wherein the pusher block body and the two attachment arms are formed integrally. 
     
     
         19 . The arm assembly of  claim 16 , further comprising:
 the linkage, wherein the linkage is configured to attach to a piece of adjustable furniture; and   a fastener removably positioned within the securing aperture, wherein the fastener is configured to engage with the end of the linkage within the linkage channel.   
     
     
         20 . The arm assembly of  claim 16 , wherein the spindle nut defines a spindle passage in the pusher block body that is vertically offset and physically separated from the rigid arm passage of the pusher block body, and wherein the threaded spindle is received within the spindle passage.