Method and apparatus for transport refrigeration system control

Patent 4325224 Issued on April 20, 1982. Estimated Expiration Date:

April 29, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3500898

Control apparatus for a two-speed heat pump Patent #: 4228846
Issued on: 10/21/1980
Inventor: Smorol

Inventor

Howland, Leland L.

Assignee

Thermo King Corp.

Application

No. 06/145190 filed on 04/29/1980

US Classes:

62/196.2, For plural compressor cylinders165/256, Variable rate of heating or cooling (e.g., plural stages, etc.)236/1E, Multistage controls236/1EA, Multiple valve staging62/228.1Compressor or its drive controlled

Examiners

Primary: Makay, Albert J.
Assistant: Tanner, Harry B.

Attorney, Agent or Firm

Arenz; E. C.

International Classes

B60H 1/00 (20060101)
B60H 1/32 (20060101)
G05D 23/20 (20060101)
F25D 29/00 (20060101)
F25B 13/00 (20060101)
F25B 49/02 (20060101)
F25B 27/00 (20060101)
F25B 47/02 (20060101)

Abstract

A transport refrigeration system having the capability of either heating or cooling at high or low speed and with the compressor loaded or unloaded is controlled by a temperature control system including a heat relay 1K and a speed relay 2K, and has an auxiliary control relay CR which is operative to maintain the compressor speed at a low speed in the temperature band 48 closely above and below the setpoint temperature, and will further maintain the low speed of the compressor for a predetermined time as the temperature rises above or below the narrow temperature band through time delay means 46 which, if uninterrupted in operation for the predetermined time period will drop out the control relay so the system can resume higher speed operation.