Pinion shifting mechanism of an engine starter

• US 5,012,686 A
• Filed: 08/04/1989
• Issued: 05/07/1991
• Est. Priority Date: 08/06/1988
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Morishita, Akira, Tanaka, Toshinori, Isozumi, Shuzoo
• Primary Examiner(s): Braun, Leslie A.
• Assistant Examiner(s): Anchell, Scott
• Application Number:
  US07/389,725
• Time in Patent Office: 641 Days
• Field of Search: 74/6, 74/7 R, 74/7 A, 74/7 C, 74/7 B, 123/179 M, 290/38 R, 290/38 C, 290/48
• US Class Current: 74/7.00A
• CPC Class Codes: F02N 15/067 the starter comprising an electro-magnetically actuated lever
• CPC Class Codes: F02N 2015/061 said axial displacement being limited, e.g. by using a stopper
• CPC Class Codes: Y10T 74/13 Machine starters
• CPC Class Codes: Y10T 74/131 Automatic
• CPC Class Codes: Y10T 74/132 Separate power mesher

Abstract

A pinion shifting mechanism of an automotive engine starter is disclosed in which the pivot support 5c of the shift lever 5 on which it turns is supported at its rear side by a resilient support means 32 instead of a rigid support surface. The shift lever operatively coupling the plunger 7 of the electromagnetic switch 4 with the pinion assembly is coupled to the plunger via an engager member 15 slidably disposed in the cylindrical bore formed in the plunger. The engager member is urged backward with respect to the plunger by a helical spring 17 disposed around the engager within the bore of the plunger. When the plunger is attracted from the initial front position toward the stationary core 8 of the electromagnetic switch, the resilient support means yields first to allow a backward translation of the pivot support of the shift lever; the spring urging the engager yields only afterwards. In another aspect, the rear as well as the front side of the pivot support of the shift lever is supported by a rigid support surface; however, the two support surfaces are disposed in such a manner that a gap 51 is formed between the rear side of the pivot support of the shift lever and the forward directed support surface 23 when the plunger is at the front position.

Claims

1. An engine starter for driving a driven gear coupled to an internal combustion engine, comprising:

an electric motor having an output shaft;

a pinion assembly axially slidably mounted on said output shaft of the electric motor to be driven and rotated by the electric motor, said pinion assembly including a pinion adapted to be brought into meshing engagement with the driven gear of the internal combustion engine by a movement of the pinion assembly toward a first axial direction directed away from said electric motor;

an electromagnetic switch device disposed at a side of said electric motor and having a cylindrical plunger driven and slidable between a first and a second position in an axial direction parallel to an axial direction of said output shaft of the electric motor;

an engager member mounted to said plunger of the electromagnetic switch so as to be slidable along the axial direction of the plunger;

first urging spring means (17) for urging said engager member with respect to said plunger in an axial direction opposite to said first axial direction;

a shift lever having one end engaged with an end of said engager member and the other end engaged with said pinion assembly, said shift lever having at a middle of its length a pivot support on which the shift lever can be turned;

support surface means (22a) for limiting a movement of said pivot support of the shift lever directed toward said first axial direction; and

resilient support means (32) including second urging spring means (32b) for urging said pivot support of the shift lever in said first axial direction toward said support surface means, wherein said resilient support means allows, by a yielding of said second urging spring means, a movement of said pivot support of the shift lever in a direction away from said support means over a predetermined length, wherein when said plunger is driven from the first to the second position in a second axial direction opposite to said first axial direction, to shift said pinion assembly via the shift lever toward said first axial direction, said second urging spring means (32b) of the resilient support means yields first, before any yielding of said first urging spring means (17) occurs, to allow a movement of the pivot support of the shift lever in said second axial direction, said first urging spring means beginning to yield after said pivot support of the shift lever has been moved away from said support surface means by said predetermined length.

2. An engine starter as claimed in claim 1, wherein:

said electromagnetic switch device comprises a stationary contact and a movable contact for making and breaking energization current supplied to said electric motor, said movable contact being mounted on an extension of said plunger to be brought into contact with said stationary contact by a movement of the plunger to said second position, the movable contact being slidable over a predetermined axial yielding length upon contact with the stationary contact; and

after the plunger is driven from the first to the second position in said second axial direction and thereby the pinion is shifted via the shift lever toward said first axial direction into a full engagement with the driven gear of the engine, first by means of an urging force of said first urging spring means, and then by an additional length by means of an urging force of said second urging spring means, even then, a gap of predetermined length corresponding to said axial yielding length of the movable contact is left between the support surface means and an confronting side of the pivot support of the shift lever.

3. An engine starter as claimed in claims 1 or 2, wherein said plunger has an axially extending cylindrical bore and said engager member has a form of a cylinder and axially slidably disposed within said bore of the plunger.

4. An engine starter as claimed in claim 3, wherein a central axis of said engager member is displaced, with respect to a central axis of said plunger, toward the output shaft of said electric motor.

5. An engine starter for driving a driven gear coupled to an internal combustion engine, comprising:

an electric motor having an output shaft;

a pinion assembly axially slidably mounted on said output shaft of the electric motor to be driven and rotated by the electric motor, said pinion assembly including a pinion adapted to be brought into meshing engagement with the driven gear of the internal combustion engine by a movement of the pinion assembly toward a first axial direction directed away from said electric motor;

an electromagnetic switch device disposed at a side of said electric motor and having a plunger driven and slidable between a first and a second position in an axial direction parallel to an axial direction of said output shaft of the electric motor, a movement of said plunger from the first to the second direction being in a second axial direction opposite to said first axial direction;

an engager member mounted to said plunger of the electromagnetic switch so as to be slidable along the axial direction of the plunger;

urging spring means for urging said engager member with respect to said plunger in said second axial direction;

a shift lever having one end engaged with an end of said engager member and the other end engaged with said pinion assembly, said shift lever having at a middle of its length a pivot support on which the shift lever can be turned;

first support surface means for limiting a movement of said pivot support of the shift lever directed toward said first axial direction; and

second support surface means for limiting a movement of said pivot support of the shift lever directed toward said second axial direction, wherein a gap of predetermined length is formed between said second support surface means and a confronting side of said pivot support of the shift lever when said plunger is at said first position.

6. An engine starter as claimed in claim 5, wherein said plunger has a cylindrical bore and said engager member has a form of a cylinder and axially slidably disposed within said bore of the plunger.

7. An engine starter for driving a driven gear coupled to an internal combustion engine, comprising:

an electric motor having an output shaft;

a pinion assembly axially slidably mounted on said output shaft of the electric motor to be driven and rotated by the electric motor, said pinion assembly including a pinion adapted to be brought into meshing engagement with the driven gear of the internal combustion engine by a movement of the pinion assembly toward a first axial direction directed away from said electric motor;

an electromagnetic switch device disposed at a side of said electric motor and having a cylindrical plunger driven and slidable between a first and a second position in an axial direction parallel to an axial direction of said output shaft of the electric motor, said plunger having an axially extending cylindrical bore formed therein;

a cylindrical engager member disposed in said bore of the plunger of the electromagnetic switch so as to be slidable along the axial direction of the plunger, a central axis of said engager member being displaced, with respect to a central axis of said plunger, toward said output shaft of the electric motor;

urging spring means, disposed around said engager within said bore of the plunger, for urging said engager member with respect to said plunger in a direction opposite to said first axial direction;

a shift lever having one end engaged with an end of said engager member and the other end engaged with said pinion assembly, said shift lever having at a middle of its length a pivot support on which the shift lever can be turned; and

support means for supporting said pivot support of the shift lever.