Ratchet wrench

• US 7,743,685 B2
• Filed: 12/17/2007
• Issued: 06/29/2010
• Est. Priority Date: 08/23/2007
• Status: Active Grant

• Current Assignee: Chih-Min Chang
• Original Assignee: Chih-Min Chang
• Inventors: Chang, Chih-Min
• Primary Examiner(s): Thomas; David B
• Application Number:
  US11/958,044
• Publication Number:
  US 20090049957A1
• Time in Patent Office: 925 Days
• Field of Search: 811/778, 811/776, 811/777
• US Class Current: 81/177.8
• CPC Class Codes: B25B 13/461 with concentric driving and driven member
• CPC Class Codes: B25B 23/0035 Connection means between socket or screwdriver bit and tool

Abstract

A ratchet wrench includes a handle having two spaced pivoting walls, two through holes respectively formed through the pivoting walls, and an inner threaded section provided at one of the through holes with a length shorter than the total length of the through hole. A ratchet head has a pivoting portion disposed between the pivoting walls of the handle and a pivoting hole through two opposite sides of the pivoting portion. A screw runs through the through holes of the handle and the pivoting hole of the ratchet head and is threaded with the inner threaded section of the handle. An urging member is disposed in an accommodation chamber of the ratchet head and sleeved onto the screw with two ends thereof stopped against a periphery wall of the accommodation chamber of the ratchet head and the pivoting wall of the handle.

Claims

1. A ratchet wrench comprising:

a handle having two spaced pivoting walls at one end thereof facing to each other, each pivoting wall having a through hole through two opposite sides thereof, wherein a first one of the through holes has a smooth section and an inner threaded section, the inner threaded section has a length shorter than the total length of the through hole and the smooth section being formed closer to the pivoting portion of the ratchet head than the inner threaded section, and a second one of the through holes has a shank section;

a ratchet head having a pivoting portion pivotally disposed between the two pivoting walls of the handle, a pivoting hole through two opposite sides of the pivoting portion in alignment with the through holes of the handle, and an accommodation chamber recessed inwards at one side of the pivoting portion;

a single screw running through both of the through holes of the handle and the pivoting through hole of the ratchet head and threaded with the inner threaded section of the handle such that the ratchet head is pivotable about the screw relative to the handle and a non-threaded portion of the screw contacts against the smooth section of said one of the through holes; and

an urging member disposed in the accommodation chamber of the ratchet head and sleeved onto the screw with two ends thereof stopped against a periphery wall of the accommodation chamber of the ratchet head and one of the pivoting walls of the handle,

wherein the screw is inserted from one side of the handle, passes through both pivoting walls, and stops against the smooth section of said first one of the through holes and the smooth shank section of said second one of the through holes, such that the force acting on the screw and produced by the periphery wall of the smooth section and the force acting on the screw and produced by the periphery wall of the shank section are approximately equal in magnitude when the force generated by the user is transmitted from the handle to the ratchet head through the pivoting walls.

2. The ratchet wrench as claimed in claim 1, wherein the length of the inner threaded section of the through hole of the handle is substantially half of the total length of the through hole of the handle.

3. The ratchet wrench as claimed in claim 1, wherein the smooth section of the through hole of the one of the pivoting walls that has said inner threaded section has a diameter equal to a section of the through hole of the other one of the pivoting walls of the handle.

4. The ratchet wrench as claimed in claim 3, wherein the through hole of the one of the pivoting walls of the handle that has said inner threaded section and said smooth section is a cylinder through hole, and the through hole of the other one of the pivoting walls of the handle is a counterbore through hole defining a head section, and a shank section that has a diameter equal to that of the smooth section of the cylinder through hole.