Guide for transmission device

• US 7,476,169 B2
• Filed: 12/16/2005
• Issued: 01/13/2009
• Est. Priority Date: 01/19/2005
• Status: Expired due to Fees

• Current Assignee: Tsubakimoto Chain Company
• Original Assignee: Tsubakimoto Chain Company
• Inventors: Konno, Masahiko
• Primary Examiner(s): Siconolfi; Robert A
• Assistant Examiner(s): Nguyen; Vu Q
• Application Number:
  US11/303,697
• Publication Number:
  US 20060172835A1
• Time in Patent Office: 1,124 Days
• Field of Search: 474/111, 474/140, 474/101, 474/144, 474/145, 474/146
• US Class Current: 474/140
• 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 guide for an engine timing chain comprises a metal supporting base and a resin shoe, the shoe having integrally formed hooks for attachment to the supporting base, and integrally formed side walls for limiting lateral movement of the chain on the sliding contact surface of the shoe. A central portion of the shoe has a sandwich injection molded structure and comprises a high strength core of glass fiber-reinforced polyamide resin, and a polyamide skin layer. The side walls and the hooks are formed entirely of the skin layer material.

Claims

1. In a chain transmission comprising an endless traveling transmission chain composed of inner and outer link plates, a guide for said chain, the guide comprising:

an elongated shoe-supporting base, adapted for mounting on an engine block, the shoe-supporting base having a front surface and a back surface, first and second ends spaced from each other in the direction of elongation of the elongated shoe-supporting base, opposite side edges extending in the direction of elongation of the elongated shoe-supporting base, and a mounting hole adjacent the first end for receiving a shaft on which the shoe-supporting base can be pivoted; and

an elongated shoe having a sliding contact surface for sliding engagement with said chain, the shoe being engaged with the front surface of the shoe supporting base, and connected to and supported by, the shoe-supporting base;

the shoe having a side wall extending from said sliding contact surface in a direction such that said side wall can engage a side of the chain traveling on the sliding contact surface and thereby limit snaking travel of the chain;

the shoe also having a hook-shaped engagement portion engaged with said second end of the base, a protrusion engaged with said first end of the base, and side hooks also engageable with the shoe supporting base, each of said side hooks having a leg portion extending past a side edge of the shoe-supporting base and an inwardly extending portion engaged with said back surface of the shoe-supporting base, and said hook-shaped engagement portion, said protrusion, and said side hooks securing the shoe to the shoe-supporting base;

in which the shoe is a sandwich-molded structure having an internal core composed of resin and a skin layer also composed of resin, the resin of which the internal core is composed having a higher strength than the resin of which the skin layer is composed;

in which said side hooks include a first set consisting of a plurality of side hooks spaced longitudinally from one another along the direction of elongation of the elongated shoe-supporting base and engaged with one of said opposite side edges of the shoe supporting base, and at least one side hook engaged with the other of said opposite side edges of the shoe-supporting base, said at least one side hook being spaced longitudinally from said first end of the elongated shoe-supporting base by a distance different from the spacings of each of said side hooks of the first set from said first end, said distance being greater than the longitudinal spacing of at least one of said side hooks of the first set from said first end and less than the longitudinal spacing of at least another one of said side hooks of the first set from said first end, whereby the side hooks engaged with opposite sides of the shoe-supporting base are in longitudinally staggered relationship;

in which the side wall and side hooks are both unitary with the skin layer, and composed entirely of the resin of which the skin layer is composed;

in which said side wall comprises a low wall portion extending from said sliding contact surface by a distance less than the distance by which a connecting pin of the chain is spaced from said sliding contact surface when a pair of links connected by said pin are both in contact with said sliding contact surface;

in which the side wall also comprises a high wall portion extending to a location spaced from said sliding contact surface by a distance greater than the distance by which a connecting pin of the chain is spaced from said sliding contact surface when a pair of links connected by said pin are both engaged with said sliding contact surface, but less than the height of said chain; and

in which the low and high wall portions of the side wall are in stepped relationship, the high wall portion being disposed outward from the low wall portion by a distance greater than the amount by which the connecting pins of the chain protrude from the outer link plates of the chain, whereby a clearance accommodating the connecting pins is ensured when the outer link plates of the chain are in contact with the low wall portion.

2. A guide for a transmission device according to claim 1, in which the skin layer is composed of a polyamide resin, and the core is composed of a glass fiber-reinforced polyamide resin.