Steering Servo
Page 59
If you've noticed an error in this article please click here to report it so we can fix it.
OFFERED as an alternative to the Marks integral power-assisted steering unit, a linkage-type servo has been developed by the Adamant Engineering Co., Ltd., DaHow Road, Luton, for use on vehicles providing insufficient space for the standard unit. It comprises a double-acting hydraulic cylinder, the piston rod of which is anchored to a lug on the chassis.
Each of the two valves in the unit is controlled by a light and a heavy spring, and the tensions of these springs are so balanced that kicks resulting from road shocks are self-cancelling. A selfcentring action proportional to the manual steering effort. is provided by subjeCting-the laced f the control plunger to a...pressure equal to that of the fluid in the_operaiing end of the cylinder, and it is stated by the makers that "feel is also proportional to the force applied to the steering wheel.
This is a function of the equilibrium existing ,between the self-centring force, combined with the force exerted by the heavier spring, and the drag-link force.
Because the valves are preloaded, a light steering effort does not actuate the mechanism and the vehicle is under direct control during normal running. In the event of hydraulic failure, full manual control is automatically restored. The unit is employed in conjunction with an engine-driven pump, a flow control valve and combined reservoir and filter.
.5.111.111-.T. Standards NEW standards covering braking systems of articulated vehicles, fuelinjection equipment and semaphore-type direction indicators have been issued by the Society of Motor Manufacturers and Traders. The demarcation of work in the construction of trolley buses between electrical-equipment manufacturers, chassis manufacturers and bodybuilders has been revised, and a standard method of measuring forward driving vision from a vehicle has been set out,
No Bellows
PIPE couplings capable of accommodating tube misalignment up to in.. tube separation up to Iin. and allowing tzln tube flexure have been produced by Aero Controls, Ltd., Weedon Road, Northampton. They are stated to eliminate the necessity of metal
bellows in pipe runs, and as they can be installed after tubes .are in place the structural apertures need be no larger than the standard bead on the tube. An axial movement of 0.35 in. is permissible. Little more than hand tightening is required to achieve pressure tightness over -a large temperature range.
Known as Acflex pipe couplings, they incorporate features employed in aircraft practice. A full range of couplings is available for tubes with outside diameters of-+ in. to 3 in. with fin, increments, and of 3+ in., 4 in. and 5 in. Another range for tubes of fi in. outside diameter is also offered.
Applying Caulking TWO guns for applying caulking and an 'anti-vibration medium for application to metal panels are offered by Expandite, Ltd., Chase Road, London, N.W.10. One of the guns is handoperated whilst the other works offa compressed-air supply. A third type is is simplified tool for small garages.
Known as Aquaplas, the sound-deadening and thermal-insulation medium is claimed to stiffen the panels to which it is applied. It may be painted over, and is available in A-cwt. and 1-cwt. drums.
Stillage Truck
REPLACING a model with a capacity of 10 cwt., a 2,000-1b. stillage truck has been introduced by A. Hirst and Son, Ltd., Meadow Lane, Dewsbury. It is of the stand-on battery-electric type, and measures 2 ft. 6 in. wide by 5 ft. long with a 3-ft. stillage frame. Capable of
turning in its own length., truck has a rear wheel with a 180-dee lock.
The control offers three forward and three reverse speeds up to a maximum of 4 m.p.h. The brake acts on the transmission, and the rear wheel is chaindriven. Raising of the frame is by a separate pump motor unit.
Swedish Lamps
QWEDISH-MADE Johnson auxiliary lamps are now being 'sold in this country, and certain countries overseas, by Aviamotive Services, Ltd., Accommodation Road, Hodford Road, London, N.W.11. Types available include a driving lamp and a fog lamp, each at £3 19s. 6d. plus bracket at 12s. 6d., a reversing lamp at £3 10s. plus 10s. for the bracket, and the Spotfinder.
This unit projects a pencil beam and may be swivelled by hand.: Of likely application to ambulances it costs £7 19s. with a 4-in lens or £8 19s. with a 5fin. lens.
Valuable Directory
THE latest edition of "Farm Mechanization Directory " (Temple Press Limited, El 10s., plus Is. fid. by post), although primarily intended for the progressive farmer, is of further value to haulage operators in 'country areas as it lists and describes all the modern pieces of equipment with which they are likely to deal. As, also, many mechanicalhandling appliances are based on tractors, the summarized test reports on current models in the Directory will be of wider value.
Similarly, various types of auxiliary engine and conveyor-type loader are described, and there is a buyers' guide with references ranging from post-bole diggers to refrigerators.