Utility truck base reinforcement and method of manufacture
View Patent ↗A utility truck with arched reinforcing rods incorporated into the base of a plastic truck during molding. The reinforcing rods are held in place in a mold at a predetermined distance above the mold's inner surface by spacers attached to the ends of the rods. Plastic is molded around the rods, with more plastic provided below the rods than above them, so that, when the plastic truck is removed from the mold and allowed to cool, the plastic will contract to a greater extent than the metal rods, causing the base and the reinforcing rods to bow upward, creating a convex arch in the truck's base. The arch provides an inherently strong, bridge-type structure that substantially strengthens the load-bearing capability of the truck, yet requires less reinforcing material than conventional supplemental chassis structures. In another embodiment, caster base mounts are also molded into the bottom of the truck, providing a utility truck with a unitary chassis structure.
1. A reinforced utility truck comprising:
a substantially planar plastic utility truck bed having a top surface and a bottom surface and a bed thickness between the top and bottom surfaces, the bed also having a width from a side of the bed to an opposite side of the bed,
an elongated reinforcing rod having a first end and a second end and a middle portion between the first and second ends, wherein the rod is embedded within the bed thickness and extends in a width direction along the width of the bed, and wherein the rod is bowed upward in the middle portion in an upward direction toward the top surface of the bed.
2. The reinforced utility truck of claim 1 , wherein the reinforcing rod is formed of metal.
3. The reinforced utility truck of claim 1 , wherein the bed thickness further comprises a lower bed thickness between the bottom surface of the bed and the reinforcing rod and an upper bed thickness between the top surface of the bed and the reinforcing rod, wherein the upper bed thickness is less than the lower bed thickness.
4. The reinforced utility truck of claim 1 , further comprising a rod spacer connected to the first end of the rod, wherein the rod spacer extends from the first end of the rod downward to the bottom surface of the bed.
5. The reinforced utility truck of claim 4 , further comprising a second elongated reinforcing rod having a second rod first end and a second rod second end and a second rod middle portion between the second rod first and second ends, wherein the second rod is embedded within the bed thickness and extends in a direction along the width of the bed, wherein the second rod is parallel to the elongated reinforcing rod and is bowed upward in the second rod middle portion in a direction toward the top surface of the bed, and wherein the spacer is connected to the second rod first end.
6. The reinforced utility truck of claim 4 , further comprising a second spacer connected to the second end of the rod.
7. The reinforced utility truck of claim 5 , further comprising a second spacer connected to the rod second end and to the second rod second end.
8. The reinforced utility truck of claim 1 , further comprising a reinforcing rib formed in the bed, wherein the reinforcing rib extends along the width direction of the bed parallel to the reinforcing rod.
9. The reinforced utility truck of claim 5 , further comprising a reinforcing rib formed in the bed, wherein the reinforcing rib extends along the width direction of the bed parallel to and between the reinforcing rod and the second reinforcing rod.
10. The reinforced utility truck of claim 1 , further comprising at least one wheel base structure embedded within the bed thickness, the wheel base structure comprising a metal loop and at least one spacer nut connected to the metal loop, wherein the spacer nut further comprises a threaded bore, and wherein the spacer nut extends downward from the metal loop to the bottom surface of the bed and the threaded bore of the spacer nut is exposed to the bottom surface of the bed.
11. The reinforced utility truck of claim 10 , further comprising at least one wheel mounting secured to the wheel base structure by a bolt screwed through the mounting plate and into the threaded bore of the spacer nut.
12. A utility truck unitary chassis structure comprising:
a utility truck comprising a bed and side walls extending up from the bed, the bed further comprising a bed top surface and a bed bottom surface and a bed thickness between the bed top and bottom surfaces, and the bed further comprising a bed width from a first side of the bed to a second side of the bed,
first and second elongated reinforcing rods, each rod having a first end and a second end and a middle portion between the first and second ends, wherein each rod is embedded within the bed thickness and the rods are parallel to each other and a space is formed in the bed between the first and second rods and each rod extends across the width of the bed, and wherein the bed thickness further comprises a lower bed thickness between the bottom surface of the bed and the reinforcing rods and an upper bed thickness between the top surface of the bed and the reinforcing rods, wherein the upper bed thickness is less than the lower bed thickness, and wherein each reinforcing rod is bowed in the middle portion in an upward direction toward the top surface of the bed, and
a reinforcing rib formed in the bed of the utility truck in the space between the first and second reinforcing rods.
13. The utility truck unitary chassis structure of claim 12 , wherein the utility truck is formed of a plastic material and the first and second reinforcing rods are formed of metal.
14. The utility truck unitary chassis structure of claim 12 , further comprising rod spacers connected to the first and second ends of the first and second reinforcing rods, wherein the rod spacers extend from the ends of the rods downward to the bottom surface of the bed.
15. The utility truck unitary chassis structure of claim 12 , further comprising a wheel mounting base embedded within the bed thickness, the wheel mounting base further comprising a spacer nut connected to the wheel mounting, wherein the spacer nut extends downward from the wheel mounting base to the bottom surface of the bed and a bottom portion of the spacer nut is exposed to the bottom surface of the bed.
16. The reinforced utility truck of claim 15 , further comprising at least one wheel assembly secured to the bottom portion of the spacer nut.