Self-damping Ring Spring
Page 53
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BASICALLY comprising a series of inner and outer sections, the cushioned-impact ring spring being produced by Ring Springs, Ltd , Netherton Iron Works, Dudley, has been successfully used in a number of industrial applications and is now available fo.:vehicle suspensions.
The spring possesses an inherent self-damping characteristic, which should provide efficient shock absorption when it is employed as a suspension member. Each outer spring has a conical surface on the inside, and a similar conical surface on the periphery of the inner section mates with the cone formed by adjacent outer sections. When axial pressure is applied, the inner rings are compressed telescopically in the normal way and the outer rings expand radially.
An important aspect of the principle' is that there is no torsional loading; the total stroke of the spring is the sum of the displacements of individual sections, and therefore the number and size of the sections govern the rated maximum load of the spring. A large amount of energy is absorbed during disPlacement by the contact of the conical surfaces.
When the load is released, dissipation of energy is progressive and closely controlled by the action of the cones. It is claimed that about 70 per cent, of the recoil energy is absorbed and that the spring has a higher capacity and a longer life than conventional springs of comparable rating.
Compact Transformer
WITH a power output reportedly equal to other welding transformers three or four times its size and weight, the Fararc 200, produced by Portable Welders, Ltd„ Castle Mills, Buckingham, is claimed to be the first unit of this type to use a toroidal wiring principle.
It will operate off a 200-250 v. or 400-440 v. mains supply to give an output of from 60-230 amp. with a maximum continuous rating of 200 amp. Glass-fibre insulation impregnated with silicone varnish is used for the windings, with cooling by a fan. The transformer can operate at temperatures ti) to 180n C.
The Fararc 200 does not require a corrector condenser, and is housed in a 14-in.-square ease. It weighs only 70 lb. and will weld steel 1 in. thick.
Also new from Portable Welders are two electrode-tip dressing tools, the Industrial for :1-in.-diameter and the Junior for -1,-in.-diameter tips.
Testing Circuits
PRICED at 5s., a circuit tester of the type with a translucent plastics handle incorporating a bulb is being produced by J. Stead and Co., Ltd., Manor Works, Sheffield, 2. The lead from the handle is about 2 ft. long.
Socket Sets
THREE sets of solid forged hexagonal sockets being produced by Thomas Meldrum, Ltd., Freedom Works, John
Street, Sheffield, 2, under their trade name of Melco, are of the i-in. square drive type.
Whitworth and S.A.E. ranges contain 11 sockets, whilst 12 sockets are provided in the metric sets. Each size range is contained in a metal box and includes a speed brace, a right-angle key and 5-in. and 10-in, extensions. The sets are priced at £4 19s. 6d. each complete.
• Double Insulation
DRICED at £9 17s. 6d. retail, the
Safetymaster is a 4K-in. drill introduced by Wolf Electric Tools, Ltd., Hanger Lane, London, W.5, featuring double insulation. The motor has no metallic contacts. The armature shaft is shrouded by a sleeve and the outer casing has a lining to ensure that there is no electrical contact with the operator should a fault occur.
The company say that double-insulated tools are regarded as being much safer than single-insulated types with an earth wire. Spindle speed of the Safetymaster running light is 3,600 r.p.m. and under full load 2,400 r.p.m. A wide range of special tools is available for use in conjunction with the drill.
Rigid Extrusions A BOOKLET describing Rockite rigid r-k extrusions is obtainable from British Resin Products, Ltd., Devonshire House, Piccadilly, London, W.1. Made from phenolic moulding materials, the extrusions are formed in a variety of sections and are being increasingly used by bodybuilders as they are colour fast, do not require polishing and are resistant to heat and weather.
High-pressure Gun SELLING at £2 5s„ a lever-operated • grease gun with a 1-1b. reservoir and a delivery pressure of 6,000 p.s.i. is available from the Alernite Division of Stewart Warner, Ltd., Harlow, Essex. It supersedes the company's model 4023 and can he obtained with an 8-in, extension or a hydraulic coupler.
Workshop Crane
rAPABLE of lifting up to 20 cwt., a
hydraulically operated floor crane introduced by Mann Egerton and Co., Ltd., Prince of Wales Road, Norwich, is called the Ilydrocrane 20. It is mounted on four wheels, the column and base of the structure being construction.
The hydraulic ram, which raises the pivoted lifting arm, gives a maximum lift of 5 ft. 4 in. when the jib is fully extended to allow a reach of 5 ft. 9 in. In this position 10 cwt. can he lifted. The maximum, lift and reach for a 20-cwt. load are 4 ft. and 4 ft. 5 in, respectively.
Protecting Wood
EXCEPT1ONAL weathering properties are claimed to be offered by Isocyne, a clear protective lacquer for use on wood, introduced by the British Domolac Co., LtdHarrow Manor Way, London, S.E.2. The lacquer has good durability and resistance to chemicals and abrasion.