Patents by Inventor John Andrew Larson

John Andrew Larson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7121169
    Abstract: A ratchet useful for wrenches is provided having a pawl and a main gear that reside in a case, wherein the pawl is biased to engage teeth of the main gear to permit rotation in a selected direction. According to an aspect of the invention, a biasing mechanism is housed within the pawl and acts outwardly from the pawl against one or more ramped surfaces formed in the case, thereby biasing the pawl rotationally. For example, the biasing mechanism may be a coil spring housed within a bore extending through the pawl, aligned parallel to an axis of rotation of the pawl. The spring is compressed between two ball bearings, urging the ball bearings axially outwardly against the ramped surfaces. The ramped surfaces are shaped so that a component of the force of the ball bearings creates a rotational moment on the pawl.
    Type: Grant
    Filed: January 14, 2004
    Date of Patent: October 17, 2006
    Assignee: Precision Instruments, Inc.
    Inventor: John Andrew Larson
  • Patent number: 6948410
    Abstract: A torque wrench is provided having body and a handle that is rotatably mounted to the body for adjusting the torque setting, and an axially movable sleeve operable to selectively lock the handle. The sleeve includes a rigid member and an elastomeric member, such as an O-ring, and the sleeve is configured to act against a locking ball held in a bore of the handle. The sleeve is selectively movable between two positions: (a) a locked position wherein the rigid member firmly retains the locking ball seated in one of several detents in the body, thereby preventing rotation of the handle; and (b) an unlocked position wherein the elastomeric member biases the locking ball inwardly, deflecting when the locking ball unseats from the detent to permit handle rotation. When the sleeve is in the unlocked position, the locking ball can incrementally “click” over the detents during handle rotation.
    Type: Grant
    Filed: March 4, 2004
    Date of Patent: September 27, 2005
    Assignee: Precision Instruments, Inc.
    Inventor: John Andrew Larson