# US 4,397,476 A · Collapsible trailer

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- Number: US 4,397,476 A
- Document ID: US4397476A
- Status: Granted
- Kind: A
- Application number: 06/233,127
- Filed: 1981-02-10
- Granted: 1983-08-09
- Earliest claimed: 1981-02-10
- Inventors: Philip B. Bolyard; Patricia A. Bolyard
- Web page: https://patentgrep.com/patent/US4397476A

## CPC

- B62D 63/061: {Foldable, extensible or yielding trailers (foldable caravans B60P3/34; adjustable chassis frames B62D21/14)}
- B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M)

## Abstract

A full trailer frame is provided including an elongated central member and a pair of opposite end transverse members. The elongated central member is longitudinally extendible and retractable and each end of each transverse member has the base end of a support arm pivotally supported therefrom for angular displacement about an upstanding axis between an extended position with the support arm free end extending outwardly of the corresponding transverse member end and a folded position closely paralleling the central member and projecting toward the remote end of the central member. The free ends of the support arms have wheel journalling spindles pivotally mounted thereon for oscillation about upstanding axes with the spindles being swingable between first positions with the spindles generally paralleling the corresponding support arm and projecting endwise outwardly of the free end thereof and second positions with the spindles disposed at generally right angles relative to the corresponding support arms and projecting laterally outwardly therefrom when the support arms are in the folded position. The spindles may be releasably locked in the first and second positions thereof whereby the trailer may be moved laterally or longitudinally when the support arms are in the extended positions and the trailer may be moved longitudinally when the support arms are in the folded positions.

## Claims

### Claim 1

A collapsible trailer including an elongated central structural component, a pair of transverse structural members mounted to the opposite ends of said central structural component, a pair of support arms including base and free ends pivotally attached at the base ends thereof to the opposite ends of each transverse structural member for swinging about upstanding axes between extended positions with their free ends projecting outwardly of the corresponding transverse structural member end, and folded positions closely paralleling said central component and projecting toward the remote end of the central component, a wheel spindle pivotally supported from the free end of each arm for angular displacement between a first position with said spindle generally paralleling the corresponding arm and a second position with the spindle disposed at generally right angles relative to the corresponding arm, said support arms being swingable between said folded and extended positions independent of angular displacement of said wheel spindle relative to said support arms, means releasably connected between said support arms and shiftable along said central structural member for selectively releasably securing said support arms in said extended positions and folded positions.

### Claim 2 (depends on 1)

The combination of claim 1 wherein the spindles pivotally supported from the ends of one of said transverse members include steering arms projecting outwardly therefrom in a direction extending longitudinally of said central structural component and outwardly of the corresponding central component end when the last mentioned spindles are disposed in the second positions thereof, and a tongue structure pivotally connected between the free ends of said steering arms.

### Claim 3 (depends on 2)

The combination of claim 2 including means removably connectable between the spindles of the other of said transverse members when the last mentioned spindles are in the second positions thereof and the corresponding support arms are in the extended positions.

### Claim 4 (depends on 1)

The combination of claim 1 wherein said elongated central component includes relatively extendable and retractable opposite end portions from which said transverse members are supported, and means operative to releasably secure said opposite end portions in the extended and retracted positions thereof.

### Claim 5 (depends on 4)

The combination of claim 4 wherein the spindles pivotally supported from the ends of one of said transverse members include steering arms projecting outwardly therefrom in a direction extending longitudinally of said central structural component and outwardly of the corresponding central component end when the last mentioned spindles are disposed in the second positions thereof, and a tongue structure pivotally connected between the free ends of said steering arms.

### Claim 6 (depends on 5)

The combination of claim 5 including means removably connectable between the spindles of the other of said transverse members when the last mentioned spindles are in the second positions thereof and the corresponding support arms are in the extended positions.

### Claim 7

A collapsible trailer including an elongated longitudinal central component and opposite end transverse components supported from the opposite ends of said central component and projecting outwardly of opposite sides of said central component, each of said transverse components having a spindle assembly associated with each end thereof with each spindle assembly including a horizontal spindle upon which a support wheel is journaled, support means supporting each spindle assembly from the corresponding transverse component end for selective shifting between a laterally retracted inboard position with the corresponding spindle disposed transverse to said central component and a laterally extended outboard position with the corresponding spindle disposed transverse to said central component, said support means including means operative to shift said spindles, during movement between said inboard and outboard positions, longitudinally of said frame to decrease and increase, respectively, the wheel base of said trailer as the track thereof is decreased and increased, said support means including means mounting each of said spindles for manual angular displacement about an upstanding axis relative to the corresponding support means, to thereby enable each of said spindles to be adjusted transverse to said central component when said spindles are in both the retracted and extended positions.

### Claim 8 (depends on 7)

The combination of claim 7 wherein said support means includes means operative to also allow pivoting of said spindle assemblies, when the latter are in their outboard positions, to positions with the spindles disposed longitudinally of said central component and projecting endwise outwardly of the corresponding trailer frame end beyond the corresponding transverse component.