PRESSURE CONTACT SWITCH

• US 3,610,852 A
• Filed: 07/20/1970
• Issued: 10/05/1971
• Est. Priority Date: 07/21/1969
• Status: Expired due to Term

• Current Assignee: Daniel Lejeune
• Original Assignee: Daniel Lejeune
• Inventors: Lejeune, Daniel
• Primary Examiner(s): Smith, Jr., David
• Assistant Examiner(s): Ginsburg, M.
• Application Number:
  US05/056,360
• Time in Patent Office: 442 Days
• Field of Search: 200/61.25,82D,83J 340/58
• US Class Current: 200/61.25
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: F16K 15/20 specially designed for inflatable bodies, e.g. tyres connecting valves to inflatable bodies B60C29/00
• CPC Class Codes: G01L 17/00 Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies
• CPC Class Codes: H01H 35/34 actuated by diaphragm

Abstract

A pressure contact switch for monitoring the inflation pressure of tires comprises a piston subjected on one side to the pressure of the air in the tire and on the other side to the force of an opposing calibrated spring. A rod coaxial with the piston is formed with an inclined cam surface to push back a contact slide capable of sliding in a first bore. The rod is also formed with a guide and stop for a locking slide capable of sliding in a second bore having an axis perpendicular to that of the first bore. The two slides are urged at all times by springs in directions towards the intersection of the two bores.

Claims

1. A pressure contact switch for monitoring the pressure of a fluid, comprising a movable piston, means transmitting to the piston a force due to a pressure of a fluid to be monitored, an opposing calibrated spring bearing on the piston and urging the piston in a direction opposite to the direction in which the piston is urged by the monitored fluid under pressure, rod means connected to the piston and movable therewith, the rod means being formed with a cam surface and abutment means, a contact slide movable between an alarm position and a standby position, biasing means urging the contact slide towards the alarm position locking slide means moving between a locking position wherein it holds the contact slide in the standby position and a retracted position wherein it permits the contact slide to drop into the alarm position, and biasing means urging the locking slide means towards the locking position, the abutment means being engageable with the locking slide means, whereby the cam surface moves the contact slide away from the alarm position and the locking slide means holds the contact slide in the standby position so long as the pressure of the fluid acting on the piston is above a predetermined value, and the abutment means forces the locking slide means away from the locking position when the pressure of the fluid acting on the piston drops below a predetermined value, so that the contact slide drops into the alarm position.

2. A pressure contact switch according to claim 1 further comprising a housing formed with two bores having mutually perpendicular axes, the contact slide being movable in one of the bores and the locking slide means being movable in the other, and the biasing means for the contact slide and the biasing means for the locking slide means respectively urging the contact slide and the locking slide means towards the intersection of the two bores.

3. A pressure contact switch according to claim 1 further comprising at least one valve means limiting the rate of flow of fluid acting on the piston.