WO1997033785A1 - Light truck bed - Google Patents

Abstract

A mining truck bed is totally built of special antiabrasion steel and includes T-shaped bolsters. The bed does not require antiabrasion bed liners, and weighs less than a conventional steel bed equipped with a liner. The special antiabrasion steel has a chemical composition including: carbon 0.18/0.24; manganese 0.75/1.00; phosphorous 0.025 max.; sulfur 0.003 max.; silicon 0.20/0.40; chromium 1.60/1.80; nickel 0.50/0.85; molybdenum 0.20/0.30; titanium 0.01/0.10 min.; boron 0.001 min.; and aluminum 0.015 min.

Description

LIGHT TRUCK BED

Background of the utility

The present utility relates to a linerless truck bed fully constructed of anti-abrasion steel for use on mining trucks. Its lower dead weight allows for the hauling of a larger payload without exceeding gross vehicle weight (GV )

Summary of the utility

It s an object of the utility to carry a larger payload than a similar size standard truck bed without exceeding gross vehicle weight. With that purpose in mind, wear liners have been eliminated This decreases the unit's dead weight which in turns improves its loading capacity by about 15%. Similarly, in order to further lower its dead weight, the shape of all bolsters has been changed from a U-Shaped one to a T-shaped one (2).

It is further an object of the utility to provide at least the same or better resistance to abrasion than a similar size standard truck bed. With that in mind, all subjec-to-wear surfaces are built of anti-abrasion steel (4).

Still further, it is an object of the utility to be disposable once the wear surfaces deteriorate beyond a certain point. In this linerless utility, the wear surfaces play a structural role as w ll .

These objects of the utility and the advantages thereof will become apparent m view of the detailed description and steel formula

Detailed description of the utility

Standard truck beds currently m use consist of a pre-formed, U- shaped, structural steel bolsters frame, that clamp a case made of structural plates that welded together g ve form to the unit that holds the load, that is, the truck bed. To minimize damage from wear and impact, -an action that due to its nature can not be efficiently endured by structural steel alone- truck beds require a set of liners to act as a protective surface against the abrasion inherent to the task they are designed to perform. This is why truck beds are lined with anti-abrasion steel plates anchored to their case by means of welding, bolting or a combination of both. This extends their life but increases their weight .

The light truck bed consists of a T-shaped, 512 BHN, anti-abrasion steel frame (l)that supports a case (4) made of the same steel, that welded together give form to the truck bed. By using a special steel whose chemically balanced composition has structural as well as anti-abrasion attributes, the resulting unit is a lighter and stronger truck bed. This improves the loading capacity of the trucks so equipped Since the anti-abrasion role s performed by the case (4) and all flat surfaces of the truck bed - which also play an active and permanent structural role- the protective lining becomes unnecessary, consequently making the unit lighter. This utility represents the unprecedented use of a type of steel that was conceived for a different purpose.

The implementation of a T-shaped bolster (2) prevents the accumulation of dirt inside as it occurs with the U-shaped bolster This accumulation normally represents about 5% of additional deadweight. KEYWORDS AND FORMULA

Tensile Strength and Hardness

Brinell Hardness 418/512 BHN Yield Strength 192,000/240, 000 psi Tensile Strength 215,000/267, 000 psi Elongation 2" 12/20% Reduction of Area 40/60%

Module of Elasticity

The typical variation in the module of elasticity for this steel from room temperature to 1,000 F^a is shown below:

Test T Tension Compression

F* (psi) (psi)

R.T. 29 000, 000 30 860 000

200 28 320, 000 29 625 000

400 26 550, 000 27 774 000

600 24 780, 000 25 922 000

800 23 010, 000 24 070 000

1 , 000 21 240, 000 22 219 000

Impact (Toughness and Ductility)

Impact through a 3/4" thick absorbed energy in Ft. /Lbs.

Grain Direction Test T^s Long Transverse

R.T. 50/32 40/50 32 45/66 35/40 0 35/60 25/36 -40 25/50 20/35

Chemical Composition

Carbon .18/ .24

Manganese .75/1.00

Phosphorous .025 max.

Sulfur .003 max.

Silicon .20/.40

Chromium 1.60/1.80

Nickel .50/ .85

Molybdenum .20/ .30

Titanium .01/.10 min

Boron .001 min.

Aluminum .015 min.

Claims

1. A mining truck light bed totally built of a special anti^¬ abrasion steel, whose chemical and mechanical characteristics lend themselves exceptionally well to be utilized simultaneously as a structural and as an anti-abrasion element which, in turn, makes the use of anti-abrasion liners unnecessary. This results in a truck bed whose operational weight is equivalent to one half the weight of a standard truck bed.

2. The truck bed of claim 1, wherein all of its parts are built of the anti abrasion steel whose chemical characteristics are set forth in the definitions of Key Words and Formula.

3. The truck bed of claim 1, wherein its case interior flat surfaces perform both, the structural and anti-abrasion role, making the use of anti-abrasion liners unnecessary yielding, in turn, a lower operational weight.

4. The truck bed of claims 1 and 2, wherein its frame is made of anti-abrasion T-shaped bolsters instead of the standard U- shaped bolsters. This improvement decreases dead weight as the T-shaped bolster does not allow accumulation of dirt inside itself .

5. The truck bed of claim 1, wherein the residual tensions of the welding process are released by means of a controlled warming and cooling thermal treatment. For this process, the bed itself is used as a furnace, which benefits all elements that conform the unit.