Monitoring devices

• US 4,246,456 A
• Filed: 05/07/1979
• Issued: 01/20/1981
• Est. Priority Date: 08/01/1975
• Status: Expired due to Term

• Current Assignee: Marconi Co Ltd (BAE Systems Plc)
• Original Assignee: Marconi Co Ltd (BAE Systems Plc)
• Inventors: Leonard, Haydn A.
• Primary Examiner(s): Scott, James R.
• Application Number:
  US06/036,370
• Time in Patent Office: 624 Days
• Field of Search: 200/61.08, 200/61.4, 200/61.93
• US Class Current: 200/61.08
• CPC Class Codes: F16C 17/246 related to wear, e.g. sensors for measuring wear
• CPC Class Codes: F16C 19/52 with devices affected by abnormal or undesired conditions
• CPC Class Codes: F16C 2233/00 Monitoring condition, e.g. temperature, load, vibration
• CPC Class Codes: G01B 7/14 for measuring distance or clearance between spaced objects or spaced apertures G01B7/30 takes precedence
• CPC Class Codes: G07C 11/00 Arrangements, systems or apparatus for checking, e.g. the occurrence of a condition, not provided for elsewhere

Abstract

A monitoring device is provided for monitoring the gap between two relatively moving parts. In its preferred form the device consists of a bar of fracturable material mounted on one part and extending towards the other. A striker mounted on the other part is provided to hit and fracture the bar when the gap separation reduces by a predetermined amount. The bar is weakened at a position where fracture is desired and a conductive track is provided across the line of fracture which track is rendered open circuit as fracture occurs.

Claims

1. A safety device for providing electrical indication of machine malfunction, which comprises an elongate bar of fracturable material, means for anchoring one end of said bar upon a first machine portion to project said bar in cantilever fashion therefrom and position the free end of said bar to be struck with fracturing force by a second machine portion in response to machine malfunction, said first and second machine portions being relatively movable along a path generally normal to the longitudinal axis of said elongated bar, said bar presenting an outer surface between the ends thereof, electrical path means on said surface for providing electrical indication when said bar is fractured, said path means comprising a loop of electrically conductive material presenting spaced leg portions extending lengthwise of said bar and a bight portion joining said leg portions adjacent said free end of the bar and remote from terminal ends of said leg portions, said loop of conductive material being in the form of a thin film layer formed on and joined to said surface so as to be exposed for visual inspection while assuring rupture thereof in response to fracture of said bar, means transversely spanning said bar for weakening the same such that fracture of said bar will occur at and transversely across said weakening means, and said weakening means being further located between said bight portion and said terminal ends thereby assuring that fracture of said bar results in the rupture of said conductive material.

2. A device as defined in claim 1 wherein said weakening means is a line of reduced thickness on said elongated bar.

3. A device as defined in claim 1 wherein said second machine portion is a striker bar of relatively strong material.

4. A device as defined in claim 1 wherein said bar is made of electrically non-conductive material and said thin film layer is deposited directly thereon.

5. A device as defined in claim 4 wherein said bar is of elongate rectangular cross section and said loop is formed on one broad exterior face of the bar.

6. A device as defined in claim 5 wherein at least one further loop is provided on an opposite broad face of said bar.

7. A device as defined in claim 5 wherein more than one loop is provided on the same broad face of said bar.