1. Field of the Invention
This invention pertains to wheel assemblies for baby carriages.
2. Prior Art
A conventional or prior art wheel assembly for baby carriages is shown in FIGS. 4-6 and includes a wheel assembly consisting of two wheels 8, 8' supported on a shaft holder 9 which is fixed pivotally at one end of a supporting rod 10. A shaft 7 is inserted through the wheels 8, 8' and the shaft holder 9 between both wheels 8, 8' and then is inserted through a combining disc 72 which has an engaging groove 71 for a pulling ring 73 insert for preventing removal of the wheel 8. A cap 74 is provided to enclose and cover the assemblage.
The prior art wheels 8, 8' may be assembled or disassembled by means of the pulling ring 73 engaging the groove 71 or being pressed down to prevent disengagement from the groove 71.
However, this conventional or prior art wheel assembly is considered to have the following disadvantages:
1. Such prior art wheel assemblies have a plurality of complicated component combinations such as a combining disc having a cylindrical portion 75 and an annular hook 76 as well as wheels having ridges 77 which increases the cost for these structures.
2. In such prior art structures, the pulling ring and the shaft are made of metal which is liable to rust owing to an extended period of use in an external environment or to a defective original anti-rust treatment which results in the pulling ring being operatively defective causing difficulty in disassembling the wheel.
3. Provision of the combining disc dictates that the shaft holes of the two wheels are of different size, which results in higher manufacturing costs.