# US 4,399,890 A · Independently mounted fall prevention apparatus

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- Number: US 4,399,890 A
- Document ID: US4399890A
- Status: Granted
- Kind: A
- Application number: 06/265,407
- Filed: 1981-05-20
- Granted: 1983-08-23
- Earliest claimed: 1981-05-20
- Assignees: International Telephone and Telegraph Corporation
- Inventors: Leroy R. Bartels; John H. Lawson; Paul L. King
- Web page: https://patentgrep.com/patent/US4399890A

## CPC

- E06C 7/186: {Rail or rope for guiding a safety attachment, e.g. a fall arrest system}
- A62B 35/005: {Vertical lifelines}
- A62B 35/0068: {Anchors}
- A62B 35/04: incorporating energy absorbing means
- E06C: LADDERS (E04F11/00 takes precedence; step-stools A47C12/00; adaptation of ladders to use on ships B63B, to use on aircraft B64; scaffolding E04G)
- A62B: DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING (valves specially adapted for medical use A61M39/00; life-saving devices, apparatus or methods specially adapted for use in water B63C9/00; divers' equipment B63C11/00; specially adopted for use with aircraft, e.g. parachutes, ejector seats, {B64D17/00, B64D25/10}; rescue devices peculiar to mining E21F11/00)

## Abstract

A flexible cable safety system for a fixed ladder is mounted adjacent to and independent of the ladder. This arrangement is useful for ladders which are not designed to withstand the loads imposed when a safety system arrests the fall of a workman.

## Claims

### Claim 1

Safety cable apparatus for use in a fall prevention system adapted for use with a fluid mounted ladder in a mine, said apparatus comprising:
a flexible safety cable;
a mounting plate, said mounting plate being adapted for fastening to the ceiling of said mine by means of mounting pins;
an upper mounting bracket having upper and lower arms and a web interconnecting said upper and lower arms, said upper arm being fixedly mounted to said mounting plate, said lower arm having an aperture;
a pin having a lower portion extending through said aperture and being swaged to said cable, said pin having an upper portion having a diameter greater than the diameter of said aperture, said upper portion being supported by said lower arm;
a lower mounting bracket coupled to the lower end of said cable and fixedly mounted to a floor below said ladder;
said upper and lower brackets being positioned such that said cable is supported in proximity to said ladder.

### Claim 2 (depends on 1)

Safety cable apparatus in accordance with claim 1 comprising: means for maintaining said cable under tension.

### Claim 3 (depends on 2)

Safety cable apparatus in accordance with claim 2, wherein said lower bracket comprises an aperture, and said apparatus comprises a tie rod extending through said aperture, a clip connecting the upper end of said tie rod to the lower end of said cable, retaining means on the lower end of said tie rod, and a compression spring between said lower bracket and said retaining means to maintain said cable under tension.

### Claim 4 (depends on 3)

Safety cable apparatus in accordance with claim 3 wherein said lower bracket comprises upper and lower arms and a web interconnecting said upper and lower arms, said lower bracket upper arm comprising said lower bracket aperture, said lower bracket lower arm being mounted to said floor, said spring being retained between said retaining means and said lower bracket upper arm.