Lift axle suspension

• US 9,776,677 B2
• Filed: 02/10/2016
• Issued: 10/03/2017
• Est. Priority Date: 02/10/2016
• Status: Active Grant

• Current Assignee: Kelly W. Yakimishyn
• Original Assignee: Kelly W. Yakimishyn
• Inventors: Yakimishyn, Kelly W
• Primary Examiner(s): VERLEY, NICOLE T
• Application Number:
  US15/040,886
• Publication Number:
  US 20170225729A1
• Time in Patent Office: 601 Days
• CPC Class Codes: B60G 11/27 wherein the fluid is a gas
• CPC Class Codes: B60G 11/28 characterised by means specially adapted for attaching the spring to axle or sprung part of the vehicle
• CPC Class Codes: B60G 17/0523 Regulating distributors or valves for pneumatic springs
• CPC Class Codes: B60G 2202/152 Pneumatic spring
• CPC Class Codes: B60G 2202/412 Pneumatic actuator
• CPC Class Codes: B60G 2204/126 Mounting of pneumatic springs
• CPC Class Codes: B60G 2204/4702 pneumatically
• CPC Class Codes: B60G 2300/402 Extra load carrying wheels, e.g. tag axles
• CPC Class Codes: B62D 61/12 with variable number of ground engaging wheels, e.g. with some wheels arranged higher than others, or with retractable wheels for manoeuvring purposes only B60S
• CPC Class Codes: B62D 61/125 the retractable wheel being a part of a set of tandem wheels resilient suspension for a single set of tandem wheels B60G5/00

Abstract

A lift axle suspension for a tandem trailer has first and second suspension air bags for first and second axles. There is a lift air bag that, when pressurized, applies a lifting force to lift the second axle relative to the first axle. A first pneumatic circuit supplies compressed air to the first suspension air bag and a diverter valve and is controlled by a height selector valve that is opened and closed based on the ride height of the trailer. The diverter valve selectively supplies compressed air to the second suspension air bag and a pressure regulator that limits air pressure to a predetermined pressure. A second pneumatic supplies compressed air to the lift air bag and is controlled by a pilot valve.

Claims

1. A lift axle suspension for a tandem trailer, the tandem trailer comprising at least a first axle and a second axle, the lift axle suspension comprising:

a first suspension air bag mounted to act as suspension for the first axle;

a second suspension air bag mounted to act as suspension for the second axle;

a lift air bag that, when pressurized, applies a lifting force to lift the second axle relative to the first axle;

a first pneumatic circuit that connects the supply of compressed air to each of the first suspension air bag and a diverter valve, the flow of compressed air through the first pneumatic circuit being controlled by a height selector valve that is opened and closed based on the ride height of the trailer, the diverter valve having a first position that supplies compressed air to the second suspension air bag and a second position that supplies compressed air to a pressure regulator that limits air pressure to a predetermined pressure; and

a second pneumatic circuit that connects a supply of compressed air to the lift air bag, the flow of compressed air through the first pneumatic circuit being controlled by a pilot valve that is opened when the diverter valve is in the second position.

2. The lift axle suspension of claim 1, wherein the pilot valve is pneumatically actuated, and the pilot valve is opened when air pressure is applied to the regulator.

3. The lift axle suspension of claim 1, wherein the supply of compressed air comprises a pneumatic air cylinder connected to the first and second pneumatic cylinders.

4. The lift axle suspension of claim 1, wherein the second pneumatic circuit comprises an override switch that closes the second pneumatic circuit.