Engine starting system

• US 4,144,862 A
• Filed: 10/31/1977
• Issued: 03/20/1979
• Est. Priority Date: 10/31/1977
• Status: Expired due to Term

• Current Assignee: Clark Michigan Company Circle Drive Buchmanan Michigan A Corporation of
• Original Assignee: Clark Equipment Company (Doosan Enerbility Company Limited)
• Inventors: Estkowski, Michael H.
• Primary Examiner(s): Lazarus, Ronald H.
• Application Number:
  US05/847,294
• Time in Patent Office: 505 Days
• Field of Search: 123/196 S, 123/196 CP, 123/198 D, 123/179 A, 184/6.4, 340/270
• US Class Current: 123/196.00S
• CPC Class Codes: F01M 1/20 concerning lubricant pressure
• CPC Class Codes: F02N 11/101 for preventing engine starter actuation or engagement
• CPC Class Codes: F02N 11/103 according to the vehicle transmission or clutch status

Abstract

A system which normally prevents an attempt to start an engine while the engine lubricant pressure is high. However, in an emergency it is possible to crank the engine even though the lubricant pressure is high by operating the start switch and main switch in the reverse of the usual sequence.

Claims

1. An engine starting system comprising a circuit portion connectible between the two sides of an electrical energy source and including in sequence a main switch, a start switch and a device for energizing the engine starter, a first electrically operated relay having a predetermined operating time and embodying a normally closed switch, a second electrically operated relay having a longer operating time than said first relay and embodying a normally open switch and a second normally closed switch, means for connecting said first relay between one side of the energy source and said circuit portion between said start switch and said device, a normally open switch responsive to engine lubricant pressure, means for connecting said second relay and said engine lubricant switch in sequence between said one said of the energy source and said circuit portion between the main switch and the start switch, said last named means including a parallel connection embodying said first normally closed switch and said normally open switch, and said second normally closed switch being connected in circuit with said device.

2. A system for operating an engine starting mechanism having an electrical actuating device, comprising a main switch and a momentary contact start switch connected in series with the said device, a first relay having a predetermined operating time and connected to be energized when both said switches are closed, said first relay having a first normally closed switch, a second relay having a longer operating time than said first relay and including a normally open switch and a second normally closed switch, the said second normally closed switch being connected in circuit with said device, a normally open pressure switch responsive to lubricant pressure in the engine, means for normally preventing operation of said device when said pressure switch is closed including a circuit portion energized when the main switch only is closed, said circuit portion including said pressure switch, said first normally closed switch and said second relay, said normally open switch of the second relay connected to hold in said second relay when it has been energized, whereby said device can be operated even though said pressure switch is closed by opening said main switch to deenergize said second relay and closing said start switch first and then said main switch, thereby causing said first relay to operate and open said first normally closed switch and said circuit portion, preventing the operation of said second relay and the consequent opening of said second normally closed switch.