Ratchet screwdriver and construction method

• US 8,109,181 B2
• Filed: 05/19/2006
• Issued: 02/07/2012
• Est. Priority Date: 05/19/2006
• Status: Active Grant

• Current Assignee: Bradshaw Medical, Inc. (In'Tech Medical SAS)
• Original Assignee: Bradshaw Medical, Inc. (In'Tech Medical SAS)
• Inventors: Gao, Hua
• Primary Examiner(s): Meislin, Debra S
• Application Number:
  US11/795,963
• Publication Number:
  US 20090301267A1
• Time in Patent Office: 2,090 Days
• Field of Search: 81 61- 632
• US Class Current: 81/62
• CPC Class Codes: B25B 13/463 a pawl engaging an externally toothed wheel
• CPC Class Codes: B25B 15/04 with ratchet action

Abstract

A ratchet screwdriver with an assembly of a handle (10), a body (17), a gear (56), a pawl (21, 22, 71), and a selector (27) movable on the assembly. The selector carries a pawl actuator (38, 81) for pivoting the pawl, and there is a rotation lock (42, 92) on the selector for releasably holding the rotated selector. The selector can be axially, and also rotationally, movable on the body for controlling the lock. The assembly is along an axis (A), and there are a member (44) and axial force appliers (62, 64) effective between the body and the member, thus restricting axial movement in the assembly. There is provision for assembly along the axis from adjacent the handle. There are modifications and an assembly method.

Claims

1. In a ratchet screwdriver, a body (17, 72) having a longitudinal axis (A), a gear (56) disposed within the body and rotatable by the handle about the axis (A), a pawl (21, 22, 71) pivoted on the body and being selectively rotationally engageable with the gear, a selector (27, 73) rotatable on the body about the axis (A) to selective rotated positions on the body for engaging the pawl for selective direction of rotation drive, the improvement comprising:

said selector being axially movable on said body, and

said body and said selector being selectively relatively non-rotationably engageable for locking said selector in selected rotated positions in response to the axial and rotating movement of said selector.

2. The ratchet screwdriver as claimed in claim 1, further comprising:

a member (44) attached to said body,

said member and said selector having a pin (42, 92) extending in the axial direction to be engageable between said member and said selector for achieving the selective locking of said selector on said body.

3. The ratchet screwdriver as claimed in claim 2, further comprising:

said pin being engaged between said selector and said member to have said pin penetrate said member to a depth for the engagement, and

said selector being axially movable on said body for an axial displacement in an amount greater than said depth.

4. The ratchet screwdriver as claimed in claim 3, Furth comprising:

a plurality of springs (53) circularly spaced apart relative to said selector and operative between said selector and said body for urging said body axially to an unlocked mode.

5. The ratchet screwdriver as claimed in claim 4, further comprising:

fasteners (64) connected with said member and operative on said body and said springs, wherein said fasteners axially urge said member, said springs and said pin into axial restraint for the selector locking mode.

6. In a ratchet screwdriver, a body (17, 72) having a longitudinal axis (A), a gear (56) disposed within the body and rotatable by the handle about the axis (A), a pawl (21, 22, 71) pivoted on the body and being selectively rotationally engageable with the gear, a selector (27, 73) rotatable on the body about the axis (A) to selective rotated positions on the body for engaging the pawl for selective direction of rotation drive, the improvement comprising:

said body having a surface (60) facing in a first axial direction relative to said axis and on a first axial side of said gear for restricting axial movement of said gear,

a member (44) on a second axial side of said gear and being connected to said body for applying axial force along said axis onto said gear to restrict axial movement of said gear relative to said axis and away from said body surface (60),

said selector being an annulus and having axially spaced apart interior circular surfaces (49), and

said body and said member respectively having circular surfaces (48, 47) in sliding contact with said selector surfaces for movably guiding said selector on said body and said member.

7. The ratchet screwdriver as claimed in claim 6, further comprising:

threaded connectors (64) extending between said body and said member for drawing said body and said member toward each other in applying the axial force therebetween.

8. The ratchet screwdriver as claimed in claim 7, further comprising:

a wave washer (62) adjacent to said gear for axially forcing on said gear in response to tightening of said threaded connectors in the applying of axial force.

9. in a ratchet screwdriver, a body (17, 72) having a longitudinal axis (A), a gear (56) disposed within the body and rotatable by the handle about the axis (A), a pawl (21, 22, 71) pivoted on the body and being selectively rotationally engageable with the gear, a selector (27, 73) rotatable on the body about the axis (A) to selective rotated positions on the body for engaging the pawl for selective direction of rotation drive, the improvement comprising:

said body having a surface (60) facing in a first axial direction relative to said axis and on a first axial side of said gear for restricting axial movement of said gear,

a member (44) on a second axial side of said gear and being connected to said body for applying axial force along said axis onto said gear to restrict axial movement of said gear relative to said axis and away from said body surface (60), and

said body having a surface (55) disposed to face said handle and said selector being arranged to be axial movable toward said body surface (55) and to present a space (51) adjacent to said body for the axial movement of said selector in the assembled screwdriver.

10. The ratchet screwdriver as claimed in claim 9, further comprising:

said selector being an annulus arranged to be axial movable along said axis toward and onto said body and said member being arranged to contact said annulus for movably supporting said annulus.