Accession No
6146
Brief Description
“SUN” Automatic ‘on’ and ‘off’ time switch, mechanical clock timer for openning and closing electrical circuits
Origin
London, England
Maker
S.E.C., 120, Charing Cross Road, W.C. 2
Class
electrical
Earliest Date
1888
Latest Date
1930
Inscription Date
Material
wood (teak?); metal (brass; steel)
Dimensions
Length 310mm; width 175mm; height 90mm
Special Collection
Provenance
Donated on or before 23/01/2003. The donor collected instruments over many years, predominantly from private sales, some were obtained direct from the manufacturers who were going to throw them out.
Inscription
PATENT 3915-12
Description Notes
“SUN” Automatic ‘on’ and ‘off’ time switch, mechanical clock timer for opening and closing electrical circuits.
Wooden (teak?) box with hinged lid, containing timer mechanism. Mechanism consists of a brass clock mechanism (with two windable coil springs and a seperate brass winding key) which is attached to a circular steel timer dial, with 24 hours marked out. Above dial is an arm thats position can be altered (by unscrewing small disc above the arm) and then set in place by re-tightening the disk. To the right of the timer disk is a hinged steel arm that can hold the circuit connector (a circular steel disk mounted on a spring with two copper-plated arms attached opposite one another) in either the on or off positions. The 2 plates of the circuit connector can fit inside the two copper points at the bottom of the box. The two points contain two steel screws for attaching wiring, and the box contains two holes for the wires to pass through.
The arm would be set at the time that the user requires the timer to turn on/off, and would then rotate with the timer disk as the clock runs. When the arm reaches the alotted time, it pushes the hinged arm to the right of the timer dial. The hinged arm is attached to a clasp that holds a large circular column of metal mounted on a spring in place. Attached to the column
References
Events
Description
The circuit connector is rotated on its spring mount so as to coil it, and is then held in place -- either in the ‘on’ position, sitting connecting the two circuit points, or the ‘off’ position, sitting with both connector arms parallel to the points, in contact with neither -- by the clasp on the hinged arm.
The timer is then set by turning the small brass pointer at the side of the timer dial to the time required for activation of the timer. The arm on top of the timer dial is then put in the ‘on’ position just below the hinged arm. As the clock mechanism runs, it rotates the timer dial and the small brass pointer, which, at the pre-set time, pushes the upper brass arm upwards, which pushes the hinged arm out. This causes the clasp on the hinged arm to release the coiled circuit connector, which rotates (due to the coiled spring) to either connect or break the circuit. Because of the double clasp on the hinged arm, the mechanism can be set to both switch off and on the circuit in one setting.
30/07/2007
Created by: Joshua Nall on 30/07/2007
FM:46613
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