Blow molded wheel with axle retainer

• US 6,464,305 B2
• Filed: 01/09/2001
• Issued: 10/15/2002
• Est. Priority Date: 06/04/1998
• Status: Expired due to Term

• Current Assignee: Poly-Flex Incorporated
• Original Assignee: Floyd F. Markling
• Inventors: Markling, Floyd F.
• Primary Examiner(s): Stormer, Russell D.
• Application Number:
  US09/757,448
• Publication Number:
  US 20010001222A1
• Time in Patent Office: 644 Days
• Field of Search: 301/112, 301/118, 301/119, 301/120, 301/121, 301/122, 301/111.01, 301/111.03, 301/64.701, 301/64.705, 301/64.704, 264/249, 264/271.1, 264/274
• US Class Current: 301/111.03
• CPC Class Codes: B60B 37/10 the wheels being individually rotatable around the axles
• CPC Class Codes: B60B 5/02 made of synthetic material

Abstract

A blow-molded wheel including an axle retainer assembly. The retainer assembly includes a housing having transverse sleeves that support an axle and a spring biased retainer pin that mounts to an annular groove at the axle. The housing is supported in a cavity formed into a wheel spoke and a bore of a wheel hub and is retained upon the shrinkage of the plastic around the housing. An aperture of the pin sleeve facilitates retraction of the pin and release of the wheel from the axle.

Claims

1. A molded plastic wheel adapted to mount to an axle, comprising

a) an annular body that is integrally molded from a first material exhibiting a first density and that includes a hollow hub having an axle bore and a plurality of hollow spokes that radially extend from said hub to a hollow box defined by planar first and second side wall surfaces that extend from said spokes and orthogonal to a peripheral tread surface that extends parallel to said axle bore, wherein hollow cavities of said hub, said spokes and said box communicate with each other;

b) retainer means mounted in said axle bore for securing the wheel to the axle and comprising a retainer housing that includes i) an external surface adapted to mount in said axle bore without rotating, ii) a pin bore having first and second open ends and wherein said first open end communicates with said axle bore and said second open end abuts a wall surface displaced from said tread surface, iii) a pin mounted in said pin bore, and iv) a resilient member abutting the displaced wall surface for biasing the pin for reciprocating movement relative to the axle bore; and

c) an annular tread piece separately molded from a second material exhibiting a second density different from the first material and having a channel shape with first and second side pieces that project orthogonal to a connecting tread band and wherein said tread piece is mounted over said box such that said tread band overlies said tread surface and said first and second side pieces abut said first and second side wall surfaces.

2. A method for constructing a self retaining wheel, comprising:

a) blow molding a wheel from a first material having a first density, wherein said wheel has an annular body that includes a hub having an axle bore and a plurality of hollow spokes and webs that radially extend from said hub to a hollow box defined by first and second planar side wall surfaces that extend from said spokes to a tread surface, wherein a plurality of hollow cavities in said hub, said spokes and said box communicate with each other, and wherein said first and second side wall surfaces extend orthogonal to said tread surface;

b) extracting the wheel from a mold and, while the wheel is warm, fitting a retainer housing to said axle bore that includes a pin and means for biasing the pin for reciprocating movement to project into said axle bore and such that the pin is displaced from the tread surface;

c) mounting an annular tread piece molded from a second material exhibiting a second density different from the first material and having a channel shape with first and second side pieces that project orthogonal to a connecting tread band and wherein said tread piece is mounted over said box such that said tread band overlies said tread surface and said first and second side pieces abut said first and second side wall surfaces; and

d) permitting the wheel to cool and the plastic material to shrink around the retainer housing to secure the retainer housing to the wheel.

3. A method as set forth in claim 2 wherein at least one of said first and second sidewall surfaces includes a raised annular flange and wherein a peripheral edge of one of said first and second side pieces abuts said flange.

4. A method for constructing a self retaining wheel, comprising:

a) blow molding a wheel from a first material having a first density, wherein said wheel has an annular body that includes a hollow hub coupled to a concentric hollow box defined by first and second planar side wall surfaces that project orthogonal from a tread surface toward said hub and wherein said hollow cavities of said hub and box communicate with each other;

b) extracting the wheel from a mold and, while the wheel is warm, fitting a retainer housing to said axle bore that includes a pin and a resilient member for biasing the pin for reciprocating movement to project into said axle bore and such that the pin and resilient member are displaced from the tread surface;

c) mounting an annular tread piece molded from a second material exhibiting a second density different from the first material and having a channel shape with first and second side pieces that project orthogonal to a connecting tread band and wherein said tread piece is mounted over said box such that said tread band overlies said tread surface and said first and second side pieces abut said first and second side wall surfaces; and

d) permitting the wheel to cool and the plastic material to shrink around the retainer housing to secure the retainer housing to the wheel.

5. A method for constructing a self retaining wheel, comprising:

a) blow molding a wheel from a first material having a first density, wherein said wheel has an annular body that includes a hollow hub coupled to a concentric hollow box defined by first and second planar side wall surfaces that project orthogonal from a tread surface toward said hub and wherein said hollow cavities of said hub and box communicate with each other;

b) extracting the wheel from a mold and, while the wheel is warm, fitting a retainer housing to said axle bore that includes a pin and a resilient member for biasing the pin for reciprocating movement to project into said axle bore and such that the pin is displaced from the tread surface;

c) mounting an annular tread piece molded from a second material exhibiting a second density different from the first material and wherein said tread piece is mounted over said box such that said tread band overlies said tread; and

d) permitting the wheel to cool and the plastic material to shrink around the retainer housing to secure the retainer housing to the wheel.