THRUST MEMBER FOR SYNCHRONIZING DEVICES

Abstract

A synchronizing device in gear shift transmissions has a gear (28), a shift sleeve (30) which is displaceably engaged with the gear (28) by internal teeth (32), and thrust members (10) disposed between the gear (28) and the shift sleeve (30), each of the thrust members having a casing (12) accommodated in an axial groove (40) of the gear (28), and a spring (18) biasing a pressure member (14) against the internal teeth (32) of the shift sleeve (30). The thrust member (10) is shaped as a flat parallelepiped, and the spring (18) extends transversely of the biasing direction and is supported on the casing (12) or the gear (28) with its peripheral portion and supports the pressure member (14) with is central portion.

Description

Embodiments of the invention are described hereinafter with the aid of the drawing, in which

FIG. 1 shows an axial section of a thrust member according to an embodiment of the invention;

FIG. 2 shows a section taken along the line II-II in FIG. 1;

FIG. 3 shows the thrust member of FIG. 1 in a plan view;

FIG. 4 shows a bottom view of the thrust member of FIG. 1;

FIG. 5 shows a sectional view of the thrust member in an elastically deformed state;

FIG. 6 shows a section taken along the line VI-VI in FIG. 5;

FIG. 7 shows an axial section of one half of a synchronizing device with a built-in thrust member; and

FIG. 8 shows a cross-section of the synchronizing device at the position of the thrust members.

Claims

1. A thrust member for synchronizing devices in gear shift transmissions of a type having a gear, a shift sleeve which is displaceably engaged with the gear by internal teeth, and thrust members disposed between the gear and the shift sleeve, each of said thrust members comprising: a casing accommodated in an axial groove of the gear, the casing being shaped as a flat parallelepiped,a pressure member, anda spring biasing the pressure member against the internal teeth of the shift sleeve, and the spring extending transversely of a biasing direction thereof and being supported on one of the casing and the gear with a peripheral portion thereof and supporting the pressure member with a central portion thereof.

2. The thrust member of claim 1, wherein the pressure member is a detent body which engages a depression in the internal teeth of the shift sleeve.

3. The thrust member of claim 1, wherein the casing of the thrust member is a body molded from plastic.

4. The thrust member of claim 1, wherein the spring is supported on the casing, and the pressure member is captively held in the casing.

5. The thrust member of claim 1, wherein the casing includes a rounded external surface.

6. The thrust member of claim 1, wherein the casing has a radial outer surface formed with projections which project into gaps of the internal teeth of the shift sleeve.

7. The thrust member of claim 1, wherein the spring is a leaf spring.

8. The thrust member of claim 1, wherein the spring is accommodated in a recess of the casing and is retained by ribs projecting from walls of the casing into the recess.

9. The thrust member of claim 8, wherein the spring has a central portion extending over almost an entire width of the casing and is tapered towards ends thereof supported on the ribs.

10. The thrust member of claim 8, wherein surfaces of the ribs on which the spring is supported are slanting in a direction opposite to a direction in which the pressure member is biased.

11. A synchronizing device in a gear shift transmission, comprising: a gear,a shift sleeve which is displaceably engaged with the gear by internal teeth, andthrust members disposed between the gear and the shift sleeve, each of said thrust members comprising: a casing accommodated in an axial groove of the gear, the casing being shaped as a flat parallelepiped,a pressure member, anda spring biasing the pressure member against the internal teeth of the shift sleeve, and the spring extending transversely of a biasing direction thereof and being supported on one of the casing and the gear with a peripheral portion thereof and supporting the pressure member with a central portion thereof.

12. The synchronizing device of claim 11, wherein the pressure member is a detent body which engages a depression in the internal teeth of the shift sleeve.

13. The synchronizing device of claim 11, wherein the casing of the thrust member is a body molded from plastic.

14. The synchronizing device of claim 11, wherein the spring is supported on the casing, and the pressure member is captively held in the casing.

15. The synchronizing device of claim 11, wherein the casing includes a rounded external surface.

16. The synchronizing device of claim 11, wherein the casing has a radial outer surface formed with projections which project into gaps of the internal teeth of the shift sleeve.

17. The synchronizing device of claim 11, wherein the spring is a leaf spring.

18. The synchronizing device of claim 11, wherein the spring is accommodated in a recess of the casing and is retained by ribs projecting from walls of the casing into the recess.

19. The synchronizing device of claim 18, wherein the spring has a central portion extending over almost an entire width of the casing and is tapered towards ends thereof supported on the ribs.

20. The synchronizing device of claim 18, wherein surfaces of the ribs on which the spring is supported are slanting in a direction opposite to a direction in which the pressure member is biased.