Car wash conveyor dolly and method of making same

1. A car wash conveyor dolly adapted to move along and in rolling relation to a conveyor track comprising:

an axle;

at least one pair of cylindrical stainless steel journals mounted on said axle and having external bearing surfaces;

at least one pair of rollers mounted on said journal surfaces for rotation relative thereto, wherein said journals exhibit a surface structure produced by nitrocarburizing and polishing prior to assembly; and

wherein the rollers are polymeric.

2. A car wash conveyor dolly as described in claim 1 wherein at least some of the rollers are made of urethane.

3. A car wash conveyor dolly as described in claim 1 wherein at least some of the rollers are made of high density polyethylene.

4. A car wash conveyor dolly adapted to move along and in rolling relationship to a conveyor track comprising:

an axle having a geometric center;

in mirror image arrangement about said center, first and second pairs of nitro carburized stainless steel journals having external bearing surfaces; and

first and second roller of a polymeric roller mounted on said journal surfaces for relative rotation thereto.

5. The car wash conveyor dolly as described in claim 4 wherein at least some of the rollers are made of urethane.

6. The car wash conveyor dolly described in claim 4 wherein at least some of the rollers are made of high density polyethylene.

7. A method making a car wash conveyor dolly comprising at least one pair of cylindrical stainless steel journals having external bearing surfaces and at least one pair of polymeric rollers mounted on said journal surfaces for rotation relative thereto wherein the method comprises the steps of:

a. preheating the journals to about 750° F.;

b. nitro carburizing said journals at about 1075° F. to case harden said journals to a depth of about 0.0006 to 0.0008 inches;

c. quenching the case-hardened journals at about 750° F.;

d. mechanically polishing the bearing surfaces; and

e. assembling the rollers to the bearing surfaces.

8. The method defined in claim 7 including the further step of re-quenching the polished journals at about 750° F. prior to assembly.

9. The method defined in claim 7 wherein the quenching step is carried out in a molten salt bath.

10. A car wash conveyor dolly comprising at least one pair of cylindrical stainless steel journals having external bearing surfaces and at least one pair of polymetric rollers mounted on said journal surfaces for rotation relative thereto wherein said dolly is manufactured according to the method steps set forth in claim 7 .

11. A car wash conveyor dolly comprising at least one pair of cylindrical stainless steel journals having external bearing surfaces and at least one pair of polymetric rollers mounted on said journal surfaces for rotation relative thereto wherein said dolly is manufactured according to the method steps set forth in claim 8 .

12. A method of fabricating a car wash conveyor dolly comprising the steps of:

a. nitro-carburizing stainless steel journals having cylindrical bearing surfaces at about 1075° F. to case harden said journals to a depth of about 0.0006 to 0.0008 inches;

b. salt bath quenching the nitro-carburized journals at about 750° F.;

c. thereafter machine polishing the bearing surfaces of the nitro-carburized and salt bath quenched journals; and

d. assembling plastic rollers onto the bearing surfaces.

13. A car wash conveyor dolly fabrication method according to claim 12 wherein the method further comprises the step of re-quenching the journals after the mechanical polishing step in a salt bath at about 750° F.

14. A car wash conveyor dolly fabrication method according to claim 12 including the further step of integrating the assembled journals and rollers with additional dolly components including a roller axle such that the dolly is adapted to travel along a car wash conveyor track.