Chain guide for use in engine

• US 7,967,708 B2
• Filed: 05/28/2008
• Issued: 06/28/2011
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Tsubakimoto Chain Company
• Original Assignee: Tsubakimoto Chain Company
• Inventors: Iwata, Tomoya, Hayami, Atsushi
• Primary Examiner(s): KIM, SANG K
• Application Number:
  US12/128,175
• Publication Number:
  US 20090036242A1
• Time in Patent Office: 1,126 Days
• Field of Search: 474/111, 474/140
• US Class Current: 474/111
• CPC Class Codes: F16H 2007/0872 Sliding members
• CPC Class Codes: F16H 7/18 Means for guiding or supporting belts, ropes, or chains construction of pulleys F16H55/36

Abstract

A chain guide is composed of a resin shoe engageable with an aluminum base frame. The shoe has a hook formed at a chain entry end for engagement with a chain entry end of the base frame, and a C-shaped hook at the chain exit end engageable with a side edge of the base frame. The shoe is engaged with the base by first engaging the C-shaped hook with the side edge of the base frame, then flexing the chain entry end of the shoe until the hook at the chain entry end can receive the chain entry end of the base. The shoe is moved a short distance toward the chain exit end of the base until a projection formed on a back surface of the shoe near the chain entry end snaps into a depression formed on a front surface of the base frame, locking the shoe and base together.

Claims

1. A chain guide for use in an engine, the chain guide comprising:

an elongated shoe having a front surface for sliding contact with a transmission chain travelling along the direction of elongation of the shoe, a back surface opposite from said front surface, and a pair of side edges extending in the direction of elongation of the shoe; and

an elongated base supporting the shoe, the base having a front surface engaged with the back surface of the shoe along the direction of elongation of the shoe, a back surface, and a pair of opposed, parallel, side wall ribs extending from the front surface of the base, the ribs being elongated in the direction of elongation of the base, and spaced from each other by a distance substantially equal to the width of the shoe, whereby the ribs, by engaging the side edges of the shoe, limit lateral movement of the shoe with respect to the base while the back surface of the shoe is engaged with the front surface of the base, said base, the base also having opposite chain entry and chain exit ends spaced from each other along the direction of elongation of the base, whereby the base can be mounted so that a traveling chain moves from the chain entry end toward the chain exit end, the front surface of the base also having a depression formed therein;

wherein the shoe is in a first longitudinal position relative to the base and has a chain entry end engaged with the chain entry end of the of the base, a chain exit end engaged with the chain exit end of the base, and a projection on the back surface of the shoe, the projection extending into the depression in the front surface of the base;

the chain guide further including first hook formed on the shoe at the chain entry end thereof, and a second hook formed on the shoe at the chain exit end thereof, said hooks having base back-engaging portions engaged with the back surface of the base, said base back-engaging portions being spaced longitudinally from each other by a distance less than the length of the base, whereby said hooks are simultaneously engaged with the respective chain entry end and chain exit ends of the base when the shoe is in said first longitudinal position relative to the base, and said shoe being positionable, while between said side wall ribs, in a second longitudinal position relative to the base in which the second hook is engaged with the chain exit end of the base while the first hook is disengaged from the base and said projection on the back surface of the shoe is engaged with the front surface of the base;

wherein the projection and depression have locking surfaces, the locking surfaces being mutually engageable, when the shoe is in said first position relative to the base, to limit sliding movement of the shoe relative to the base in a direction toward the chain entry end of the base, and thereby preventing disconnection of first hook from the chain entry end of the base; and

wherein at least a portion of the shoe located between the projection and the chain entry end of the shoe is sufficiently flexible to allow the first hook to be moved into a position such that it can be engaged with the entry end of the base by longitudinal movement of the shoe relative to the base from said first position toward said second position while the projection is engaged with the front surface of the base at a location spaced longitudinally from said depression.

2. A chain guide according to claim 1, in which said depression is spaced toward the chain entry end of the base from a location mid way between the chain entry and chain exit ends of the base, and the projection is spaced toward the chain entry end of the shoe from a location mid way between the chain entry and chain exit ends of the shoe.

3. A chain guide according to claim 1, wherein the locking surface of the projection faces toward the chain entry end of the shoe, and wherein the projection has a rounded surface facing toward the chain exit end of the shoe.