Sprocket conversion kit for garage door opener

DETAILED DESCRIPTION This invention relates to a conversion kit for use at the output drive of a garage door opener to convert the drive between the output shaft of the power drive unit and the endless chain from a high speed drive to a low speed drive.
This requires providing means for effectively reducing the number of gear teeth or sprocket teeth on the output shaft, as for example, from eight to six.
A kit is provided including a drive plate which is readily assembled to the high speed sprocket of the garage door opener in a simple and effective manner.
A low speed sprocket is fixed to and co-axial with the drive plate secured to the high speed sprocket and the low speed sprocket is displaced axially from the high speed sprocket which nests in the dish-shaped recess in the drive plate.
The garage door opener includes means which would reposition the endless chain to engage the low speed sprocket rather than the high speed sprocket, as for example, a reversible idler gear.
Accordingly, it is an object of the present invention to provide a kit for adapting a garage door opener to convert from a high speed drive to low speed drive.
It is another object of the present invention to provide a conversion kit including a low speed sprocket which is adapted for mounting on the high speed sprocket of a garage door opener to drive the endless chain at a reduced speed.
It is a further object of the present invention to provide simple, inexpensive and easily installed conversion kit for modifying a garage door opener to provide relatively low drive chain speed by use of an adaptor which effectively reduces the number of teeth on the chain drive sprocket.
It is still a further object of the present invention to provide an improved sprocket adaptor including a dish-shaped drive plate which mounts in driving relation to a high speed sprocket and which supports a low speed sprocket axially spaced from and coaxial with said high speed sprocket.
Other objects and advantages of the invention will be readily apparent from the following description taken in conjunction with the accompanying drawings in which: