Ratchet Screwdriver and Construction Method

• US 20090301267A1
• Filed: 05/19/2006
• Published: 12/10/2009
• 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
• Granted Patent: US 8,109,181 B2
• Time in Patent Office: Days
• US Class Current: 81/63
• 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 handle (10) for rotating the body about the 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 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, further comprising:

a plurality of springs (53) circularly spaced apart relative to said selector and operative between said selector and said member for urging said selector axially to its 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 for axially urging said member and 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 handle (10) for rotating the body about the 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, and

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).

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

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

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

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

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.

11. The ratchet screwdriver as claimed in claim 10, 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.

12. In a ratchet screwdriver, a body (17, 72) having a longitudinal axis (A), a handle (10) for rotating the body about the 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:

the screwdriver being arranged in an assembly to have said body having an opening (18) for receiving said gear from the axial end adjacent said handle,

a member (44) disposed adjacent said handle,

said selector and said member both being arranged to be in assembly in said screwdriver because of movement along said axis from the axial end, and

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.

13. In an assembled arrangement method of a ratchet screwdriver to have a body (17, 72) with a longitudinal axis (A), a handle (10) at one end of the axis for rotating the body about the 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 gear and said selector both being positioned with respect to said body upon movement of said gear and said selector relative to said body in the axial direction away from said axial handle end, and

a member (44) being attached to said body and being axially forceable onto said gear upon movement of said member toward said body in the axial direction away from said axial handle end.

14. The assembled arrangement as claimed in claim 13, further comprising:

screws (64) applied between said said member and said body for axially holding said member and said body toward each other.

15. The assembled arrangement as claimed in claim 14, further comprising:

a wave washer (61) applied between said body and said gear for effecting axial force toward said gear upon tightening said screws.

16. In a ratchet screwdriver, a body (17, 72) having a longitudinal axis (A), a handle (10) for rotating the body about the 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 pawl (71) being pivotal on said body and said gear and said pawl having a location of engageable teeth (56, 79) and with said pawl teeth facing radially inwardly toward said axis, and

a pawl actuator (76) on said selector and disposed on a radial line (R) from said axis and being coincident with a radial line through the location of the engaged said pawl teeth for urging said pawl radially inwardly into position of engagement of the pawl teeth with said gear teeth.

17. The ratchet screwdriver as claimed in claim 16, further comprising:

said selector being a ring extending around said body and being rotatable on said body, and

said actuator being a ball (81) radially movably supported on said ring and being slidable on said pawl (71) for pivoting said pawl into engaged positions with said gear teeth (58) upon rotation of said ring on said body.

18. The ratchet screwdriver as claimed in claim 16, further comprising:

said pawl and said ring having facing arcuate surfaces (83, 84) in sliding contract with each other and in radial forcing contact for having said ring support said pawl in tooth engaged relationship with said gear.

19. The ratchet screwdriver as claimed in claim 16, further comprising:

a member (44) connected with said body and having holes (65) facing in the axial direction, and

a pin (42, 92) on said ring and extending in the axial direction and selectively into said holes for releasable rotational locking of said ring on said body.

20. In a ratchet screwdriver, a body (17, 72) having a longitudinal axis (A), a handle (10) for rotating the body about the 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:

a member (44) connected to said body,

said member arid said selector having an axially spring urged pin (42, 92) extending in the axial direction to be engageable between said member and said selector for achieving rotational selective releasable locking of said selector on said body, and

fasteners (64) connected with said member and operative on said body for axially urging said member and said pin into restraint for the selector releasable locking.

21. The ratchet screwdriver as claimed in claim 20, further comprising:

said pawl being pivotal on said body for engagement with said gear, and

said selector being annular and encircling said body and having a portion (38, 81) extending radially inwardly toward said axis for pivoting said pawl relative to engagement of said gear upon rotation of said selector.