WO2002036987A1

WO2002036987A1 - Belt installation tool

Info

Publication number: WO2002036987A1
Application number: PCT/US2001/045182
Authority: WO
Inventors: Yahya Hodjat
Original assignee: The Gates Corporation
Priority date: 2000-11-03
Filing date: 2001-10-30
Publication date: 2002-05-10
Also published as: AU2002225803A1

Abstract

A belt installation tool (10) for installing a flexible belt on a pulley. The tool (10) comprises a belt bearing surface (11) comprising a ramp having a large radius. The ramp (11) is connected to a side of a pulley adjacent to a pulley groove. The ramp (11) also comprises a surface (13) substantially normal to the ramp (11). In use, a belt is loosely placed on the ramp (11) with the ramp at one end of the pulley rotation. As the pulley is rotated, the ramp (11) and belt move with the pulley. As the pulley is rotated, the ramp (11) progressively moves to a position under and supportive of the belt. The normal surface (13) substantially simultaneously aligns the belt with the pulley groove. As the pulley rotates further, the ramp (11) supports the belt while it is trained into the pulley groove. As the pulley rotation is completed, the tool (10) disengages from the belt. Two tool may be used on opposing sides of a pulley to further facilitate installation of a belt.

Description

Title Belt Installation Tool

Field of the Invention

The invention relates to belt installation tools and more particularly to belt installation tools having an arcuate ramp surface whereby a flexible drive belt is progressively guided into a pulley groove or flat side pulley.

Background of the Invention Belt drive systems comprise a significant and widely used form of mechanical power transmission. Generally a belt runs between two or more pulleys, more particularly a driver and driven pulley and idlers.

In order to efficiently transmit power between the pulleys, the belt is installed with a predetermined preload or tension. The amount -of tension is generally a function of the horsepower and torque requirements of the drive. Increased horsepower or torque requirements will generally require a commensurate increase in the belt tension.

In order to achieve the proper tension, one or more of the pulleys is loosened so the shaft or shafts can be moved to allow a slack condition in the belt. Then, the belt is looped over the pulleys. The loosened pulley or pulleys are then pulled or tightened into a predetermined position, resulting in a tension being created in the belt. This process requires the pulley (s) to be mechanically adjusted in order to properly preload the belt.

Belts may be installed on pulley systems using other methods. For systems with an automatic tensioning device the tensioner is set, the belt is placed, and the tensioner is released to its operational location. For systems without a tensioner, a belt is wrapped around the pulleys and then a pulley is adjusted to its final location by a bracket or similar device.

Another method of installing a belt involves use of a tool that presses the belt into a pulley groove without the need for mechanically adjusting the pulleys. The tool is used adjacent to a pulley. It stretches the belt while laterally forcing it into a pulley groove.

Representative of the art is European Patent No. 0 831 247 Bl to Hutchinson which discloses a tool having a radial thrust area resting against a girth of the pulley, keeping a belt away from a pulley until till it reaches a plane spaced from a pulley surface.

Also representative of the art is US patent no. 4,193,310 (1980) to Boyer et al . which discloses a pulley having a diverging means extending radially and laterally from the rim for engaging and seating the belt on the pulley rim. This invention does not comprise a bearing surface for gradually entraining a belt on a pulley, instead, having a peg that abruptly bends the belt into the pulley groove.

The prior art apparatus forces a belt to bend over small radius portions of the tool, causing high stress concentrations that damage the belt during installation. Further, high lateral loads damage the sidewalls of the belt. Finally, the transverse motion of the belt as it moves into the pulley groove may damage the belt. What is needed is a belt installation tool having a belt bearing surface aligned at an angle to a pulley groove. What is needed is a belt installation tool wherein the belt bearing surface has a substantial radius. What is needed is a belt installation tool having a surface normal to the belt bearing surface for aligning a belt with a pulley groove. What is needed is a belt installation tool causing no relative longitudinal movement between the pulley and the belt during installatiqn. The present invention meets these needs.

Summary of the Invention The primary aspect . of the invention is to provide a belt installation tool having a belt bearing surface aligned at an angle to a pulley groove.

Another aspect of the invention is to provide a belt installation tool wherein the belt bearing surface has a substantial radius.

Another aspect of the invention is to provide belt installation tool having a surface normal to the belt bearing surface for aligning a belt with a pulley groove.

Another aspect of the invention is to provide a belt installation tool causing no relative longitudinal movement between the pulley and the belt during installation.

Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings . The invention comprises a belt installation tool for installing a flexible belt on a pulley. The tool comprises a belt bearing surface comprising a ramp having a large radius that substantially approximates the radius of a pulley. The ramp is connected to a side of a pulley adjacent to a pulley groove. The ramp also comprises a surface at an angle to and substantially normal to the ramp. In use, a belt is loosely placed on the ramp with the ramp at one end of the pulley rotation. As the pulley is rotated, the ramp and belt move with the pulley. As the pulley is rotated, the ramp progressively moves to a position under and supportive of the belt. The angled normal surface substantially simultaneously aligns the belt with the pulley groove. 'As the pulley rotates further, the ramp supports the belt while it is trained into the pulley groove. As the pulley rotation is completed, the tool disengages from the belt.

Brief Description of the Drawings The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with a description, serve to explain the principles of the invention .

Fig. 1 is a front perspective view of the belt installation tool .

Fig. 2 is a front perspective exploded view of the tool and a pulley.

Fig. 3 is a perspective exploded view of an alternate embodiment .

Fig. 4 is a perspective view of a plural use of the tool.

Fig. 5 is a side elevation view of the inventive tool.

Detailed Description of the Preferred Embodiment Fig. 1 is a front perspective view of the belt installation tool. Tool 10 is shown attached to an outer perimeter 0 of pulley P. Tool 10 comprises belt bearing surface 11. Belt bearing surface or ramp 11 tapers, describing an angle α with respect to outer perimeter 0. Belt bearing surface 11 describes radius R which is substantially equal to the radius of pulley P at the outer perimeter 0. End 18 substantially aligns with an outer perimeter 0 of a pulley P. Surface 12 describes a lesser radius than the radius R of belt bearing surface 11, see Figure 5. Arcuate surface 12 blends with belt bearing surface 11, creating a variable radius along the length of the tool between belt bearing surface 11 and surface 12. First normal surface or side flange 13 extends substantially along an entire length of an outer edge of the tool 10. Clips or fasteners 14, 15 are used to attach the tool 10 to an outer perimeter O of a pulley P. In use the pulley is rotated in direction M.

Fig. 2 is a front perspective exploded view of the tool and a pulley. Tool 10 is shown with clips 14, 15 used to attach it to an outer perimeter or rim O of pulley P. Clips 14, 15 fold or extend over the outer perimeter 0. Clips 14, 15 may be slightly crimped in order to effect a firm mechanical attachment. Surface 16 extends from the belt bearing surface 11 and surface 12 to provide mechanical stiffness to the tool.

Fig. 3 is a perspective exploded view of an alternate embodiment. Tabs or studs 17 extend normally from surface 16 of tool 10. Each tab extends through a receiving hole (not shown) in a web of a pulley or idler I.

Fig. 4 is a perspective view of a plural use of the tool. Tools 10 are shown on opposing sides of a pulley P. When the tool is to be permanently installed on a pulley it is necessary to place two of them on opposite sides of the pulley so the proper balance of the spinning pulley is maintained. In this embodiment the tools 10 are attached to a pulley as described in Figure 3. Fig. 5 is a side elevation view of the inventive tool. Belt bearing surface 11 describes radius R. Ramp or surface 12 describes radius r. Radius R is greater than radius r. Radius R substantially equates to the radius of the outer perimeter of a pulley P (not shown) . Radius R blends with radius r to form an overall variable radius which facilitates belt installation as described herein. Flange 13 has height H that may exceed the thickness of a belt (not shown) to be installed. In use, the tool has a ramp that allows the belt to be initially positioned, and a side flange 13 that holds the belt adjacent to the pulley on the tool. By turning the pulley, the belt steadily engages ramp 12 and it is stretched slightly over radius r. It then comes to the tapered portion of the ramp, surface 11, having a radius R that is equal or greater than the radius of the pulley groove/grooves (or synchronous teeth as the case may be) . As the width of the ramp gradually decreases with the tapered surface 11 in the direction of rotation, a belt is pushed over by the pulley perimeter 0 and is urged into its proper position on the pulley.

The belt can be off loaded or removed the same way, by turning the pulley the opposite direction. For offloading, the belt is initially moved to the ramp by hand or a tool such as a screwdriver. The direction of the ramp is such that loading is accomplished in a normal drive direction, and offloading is accomplished in the opposite direction. One pulley is chosen to accommodate the ramp, located at the most accessible position of the drive and with enough clearance from the surrounding components. A belt is placed around all pulleys and on the ramp of the loading pulley. By turning the engine/motor on, or by hand turning the pulleys, the belt is installed in about half a revolution (180 degrees) of the loading pulley.

In an alternate embodiment, the pulley and the tool can be made in one piece or multiple pieces from all industrial materials, utilizing known processes.

For backside pulleys and idlers without a flange, the tool can be used to install the belt without stretching it at all. This means that this invention can be used for non- stretchable belts, where there is a backside no-flange pulley or idler in the system. Most automotive drives have this type of pulley for water pump as well as idlers. Consequently, the tool can be used for non-stretch belts in most cases. It is also advantageous to load the belt in a system with an automatic tensioner using the tool rather than turning the tensioner. Also, most belt drive systems for mowing decks and garden tractors and similar products have a backside idler, which can easily be made with two or three holes/slots for the belt installation tool. This makes it much easier to replace a belt in these and similar applications .

Although a single form of the invention has been described herein, it will be obvious to those skilled in the art that variations may be made in the construction and relation of parts without departing from the spirit and scope of the invention described herein.

Claims

Claims I claim: 1: A belt installation tool comprising: an arcuate surface having an end and an outer edge; a first surface extending along the outer edge substantially normal to the arcuate surface; and fasteners for attaching the arcuate surface to a pulley.

2. The belt installation tool as in claim 1, wherein: the arcuate surface comprises a variable radius; and a substantial portion of the arcuate surface describes a radius substantially equal to the radius of a pulley.

3. The belt installation tool as in claim 2, wherein the arcuate surface end substantially aligns with a pulley groove radius .

4. The belt installation tool as in claim 3, wherein the first surface extends substantially along a length of the outer edge of the arcuate surface.

5. The belt installation tool as in claim 4, wherein the variable radius decreases along the arcuate surface in a direction away from the end.

6. The belt installation tool as in claim 5, wherein the fasteners attach the tool to a pulley edge.

7. The belt installation tool as in claim 6, wherein a height of the first surface exceeds a thickness of a belt to be installed.