A Fork Truck-cum-Crane
Page 68
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THE conversion of a fork-truck into a dual-purpose vehicle can be achieved by a scheme shown in patent. No. 711,961. (Ransomes and Rapier, Ltd., Waterside Works, Ipswich). A detachable horizontal beam is provided; this can be raised or lowered by the telescopic mast of the truck and used as a crane.
The drawing clearly illustrates the scheme, the positions that can be reached being indicated in broken line. Although a rope and hook are provided, they do not perform the actual lifting; this is done by the rising of the beam against the anchorage of a tie (1).
The rope can, however, be wound in or out to the desired free length by a small hand-operated drum (2). The extra pulleys (3) are used for the rope when a diminished radius of lift is rendered necessary. Although the lifting end of the beam has a circular path, it is so near to a straight lift as to be negligible.
A LOW-TENSION SPARKING . PLUG
IGNITION systems, other than those lot the conventional high-tension type, are . quite practicable, . and one such forms the subjeet.of patent No 711,778 (Beadix Aviation Corp., South Bend, Indiana, U.S.A.). This patent refers to a low-tension plug in which a discharge occurs across the face of a semiconductor. The voltage used-500—is quite low, but it is given a highfrequency oscillation.
The drawing shows the tip of a sparking plug according to the invention. An annular gap (1) is formed between the central electrode-and the
outer shell and this is bridged by an inlaid ring (2) of semi-conductive material. A suitable composition for this contains silicon carbide, cobalt oxide and aluminium oxide bound with a urea-formaldehyde resin.
In operation, it is believed that the initial surge of current across the semiconductor ionizes the gas in the gap and Tenders it conductive. A powerful arc is thus enabled to bridge the gap and it is this that ignites the charge.
A PUMP FOR PETROL INJECTION
APUMP for injecting volatile fuel, such as petrol, is shown in patent No. 711,724, by Scintilla, Ltd., Soleure, Switzerland. The method of controlling the output has been designed to avoid the creation of a vacuum which would tend to form vapour bubbles
A34.
The pump is worked by a single face-cam, operating in turn as many plunger units as there are cylinders in the engine. Referring to the drawing, I is the cam and 2 ODC of the pump units. The plunger, on its downstroke, draws in fuel from a pair of slots (3) which line up with slots in the plunger.
On the upstroke, the plunger is rotated through an angle sufficient to close off this path, after which injection occurs. The moment at which the plunger is rotated obviously controls the quantity injected and a variabletiming device is therefore provided,
This is achieved by causing the plunger to be rocked by an arm (4), -which is worked by a cam (5) On the central spindle. This cam is curved in outline (as indicated by the sloping face 6) and its peaks lie on a curve suited to vary the timing and duration .of the inlet period.
The cam is slidable in a vertical direction and by moving it up or down regulation is achieved. The external control is a non-rotating rod (7).
PREVENTING OVERHEATING IN MAGNETIC CLUTCHES
A DESIGN for a magnetic clutch (or .t-3. brake) is shown in patent No. 711,922, the chief feature of which is to direct any generated heat to the member best able to dissipate it. The patent comes from Eaton Manufacturing Company, Cleveland, Ohio, U.S.A.
The drawing shows a sectional view of part of the actual working faces. The outer member (1) has a plain bore, but the inner one is formed into numerous upstanding ridges (2) instead of a plain cylindrical surface. An electro-magnet is incorporated and its lines of force follow the path shown by the broken lines (3). The whole unit is filled with ironpowder in oil áü& when magnetized, the iron collects in the lines of force and establishes a frictional drive.
The essence of the patent is that the heat generated during slipping has only a limited path to the inner member (through the ridges), but can reach a large area on the outer easing, which can be adequately cooled. In addition, the denser flux through the ridges means that the slipping action occurs mainly on the -bore of the outer member, where the magnetism is not so dense.
GAS LAMPS RUN FROM BATTERIES
PATENT No. 712,099 (R. Dries, I Arcadian Gardens, Hadleigh, Essex) gives details of a circuit for enabling gas-discharge lamps to be run from vehicle batteries. The necessary high voltage is generated by a rotary converter and fed to a multi-electrode valve through an oscillatory circuit comprising a transformer with a capacitor across the primary. The high-frequency ac. output may be further stepped up by another transformer. The specification gives the circuit diagram in full.
A SLIDING DOOR FOR BUSES AND COACHES
IN designing coach bodywork, it is desirable, both for practical and aesthetic reasons, to have a smooth exterior and this means that doors when closed should be substantially flush with the general surface of the body: To achieve this requirement using a sliding door, is the object of a design shown in patent No. 709,914, by H. Smith and Weathershields, Ltd., 48 Moor Street, Birmingham, 4.
The patent gives eight drawings all of which must be studied to understand fully the mechanism employed. In brief, the front end of the door is guided by rails set at a slight angle to the body whilst the rear end is mounted on a pair of small cranks, one at the top and one at the bottom.
To open the .door, .movernent of the handle first swings the rear edge of the door inwards and then the whole door can be moved along in the guides.