ESCALATOR SYSTEM HAVING FAULT INDICATOR

• US 3,580,376 A
• Filed: 01/02/1969
• Issued: 05/25/1971
• Est. Priority Date: 01/02/1969
• Status: Expired due to Term

• Current Assignee: Schindler Elevator Corporation (Schindler Holding AG)
• Original Assignee: Richard C. Loshbough
• Inventors: Loshbough, Richard C.
• Application Number:
  US04/788,474
• Time in Patent Office: 873 Days
• US Class Current: 198/323
• CPC Class Codes: B66B 29/005 Applications of security monitors

Abstract

An escalator system having a safety circuit to prevent operation under unsafe conditions and including a trouble indicator arranged to respond to any of a plurality of trouble-sensing switches in an escalator control circuit and structure. Two indicators are provided for each trouble condition, one which is actuated while trouble persists and the other is latched to retain an indication of trouble after the sensing circuit has been reestablished whereby an indication of a currently existing trouble condition is augmented by an indication of a previously existing trouble condition. Advantageously, the indicator can be connected and disconnected from the escalator system and is mounted in a portable case.

Claims

1. An escalator system comprising an escalator, an electrical drive for said escalator;

an electrically controlled brake for said escalator;

means for sensing a malfunction in said system;

means for disabling said drive and applying said brake in response to said sensing means;

indicator means responsive to said sensing means while said sensing means responds to said malfunction;

latching indicator means responsive to said sensing means and maintained responsive following the termination of response of said sensing means; and

reset means for said latching indicator means.

2. A combination according to claim 1 including a second means for sensing a second malfunction in said system;

a second means for disabling said drive and applying said brake in response to said sensing means;

a second indicator means responsive to said second sensing means while said second sensing means responds to said second malfunction, and a second latching indicator means responsive to said second sensing means and maintained responsive following the termination of response of said second sensing means;

said reset means resetting said first and second latched indicator means.

3. A combination according to claim 2 including portable means mounting said indicators and releasable means for connecting said indicators to said sensing means.

4. A combination according to claim 1 including a bistable trigger circuit responsive to said sensing means and operatively coupled to said Latching indicator to maintain said latching indicator responsive following the termination of response of said sensing means.

5. A combination according to claim 1 wherein said indicator comprises a lamp and wherein said latching indicator comprises a lamp.

6. A combination according to claim 1 wherein said means responsive to said sensing means comprises, means responsive to an electrical signal for maintaining said drive in operation and said brake released while a signal is applied, a source of an electrical signal, a first switch to couple said source to said signal responsive means and which is transferred from a circuit-closing to a circuit-opening condition in response to a sensed malfunction, and a second switch to couple said source to said indicators which is transferred from a circuit-opening to a circuit-closing condition in response to a sensed malfunction.

7. A combination according to claim 6 including a source of direct current, a controlled rectifier having an anode, a cathode and control electrode, means connecting said anode, cathode and latching indicator including a unidirectionally conductive device across said source of direct current, and a network connected between said second switch and said control electrode to apply a signal to said controlled rectifier initiating anode-cathode conduction therein.

8. A combination according to claim 7 wherein said first-mentioned source supplies alternating current, and said first-mentioned indicator comprises a lamp across which said source is connected by said second switch, and wherein said network includes a unidirectionally conductive device to apply a unidirectional signal from said first-mentioned source to said control electrode.