AT THE HEART OF THE ROAD TRANSPORT INDUSTRY.

Call our Sales Team on 0208 912 2120

Automatic Brake That _ Prevents Overspeeding

29th July 1949, Page 26
29th July 1949
Page 26
Page 26, 29th July 1949 — Automatic Brake That _ Prevents Overspeeding
Close
Noticed an error?
If you've noticed an error in this article please click here to report it so we can fix it.

Which of the following most accurately describes the problem?

.1-1.

A BRAKE which will vtomatieally apply itself at a Lertain road

S pec i s disclosed in patent No, 621;195, by the Clayton Dewandre Co., Ltd-, and S. Edge, both of Titanic Works, Lincoln. Although the brake is intended mainly for tractor-trailer outfits, its use is not limited to these,

The device shown is an additional unit for incorporating in the wellknown air-operated braking system manufactured by this concern, and comprises a centrifugally. controlled brake-valve driven in accordance with ront speed. Referring to the drawing,

the' spindle. (1) is fitted with a pulley and is. driven. by..a belt from a Convenient •point on the transmission. The spindle carries centrifugal weights which, when overdriven, move a rocking [ever (2). The latter. then closes the air-valve (3) and opens an atmospheric' vent -valve (4) causing brake applkatiort.

AN IMPROVED ". RUBBING". BRAICE .

E ofthe modern methods f kJ eliminating host motion in brake mechanismsis to keep the .shoes con tinually in light rubbing contact with the drum. But with a leading-shoe brake, there is the risk that the toe may be picked up by the drum, and to avoid this is the aim of a scheme shown in patent No. 620,543, by U. . Bracewell, 548, Tolle/ Lane, Bradford,

The drawing shows one of the shoes employed in the scheme; it is made in two parts, a main piece (I) and a secondary part (2) about half the length of the former, and the two units are pivotally joined by a pin (3), although the facingls an one piece. The fulcrum point of the shoe is about end 4, the expander being at the other end.

A tension spring (5) exerts an inwardly directed Nee on the two pieces, and thus creates a slight" out-ofround," as illustrated by gap 6 at the toe end, although the facing on the short shoe remains in rubbing contact. An adjusting screw (7) is used to control the syldtht of the gap.

• A CENTRIFUGAL CLUTCH IMPROVEMENT

PATENT No. 618,987, comes from the Borg and Beck Co., Ltd.,

• Leamington Spa, and deals with improvements in the design of centrifugallY operated clutches. According to the patentee, when such a clutch starts to engage, it must first take up all the 'backlash in the transmission, arid in doing so,. sometimes prnduces a slight "bump." To avoid 'this is the object of the invention.

The method of eliminating the shock is to exert a slight drag on the clutch before engagement commences so that backlash is not initially present. But such adrag; if present all the time, would make the •engagement of the gear noisy, and it is a feature of the scheme that the drag is not applied until after a gear has been engaged.

In the central region of the clutch_ there is provided a small spring (1) which loads the driven plate slightly to produce the .drag. But if sleeve. 2 be moved to the -right, the spring pressure is relieved and no drag occurs. .Thre, sleeve movement can be performed either by mechanical means or, as in the present instance; by a solenoid (3) and a lever (4): The solenoid circuit is controlled by a contact on the gearbox slider (5), and is arranged so that drag is present only wherra gear is engaged.

1NJECTION-PUMP CONTROL FOR BLOWN ENGINES

PATENT No. 621,038, comes from C.A.V., Ltd., and W_ Nicolls, both of Warple Way, London, W.3, and deals with the modification of centrifugally controlled -injection pumps to suit supercharged oil engines.

In the drawing, 1 is the .centrifugal

• governor; this is of conventional design and operates the rack-rod (2) of the pump via a lever (3). But the lever carries 'Upon itself a second lever (4), the movement of which can increase or decrease the main movement by a small amount. The position of the second lever is governed by a spring-loaded piston (5) which is subject to the pressure of the air sutiply; it moves towards the right with an increase in pressure.

AN ANTI-LEAD COATING FOR VALVES T"use of a nickel-chrome alloy for a lead-resistant coating for valves is known, but unexpected failures have nevertheless occurred. According to patent No. 618,607, the failures are clue to the fact that the coating contains iron which has diffused from the valve-head, and which destroys the protective action of the coating if present in excess of

per cent.

The patentees, W. Davies, 68, Long

moor Lane, Breaston, Derby, and others, disclose a method of ensuring that the applied layer is made iron-free. To achieve this, the valve is first coated with the alloy in the usual way, and is, then machined to leave a thickness of about 0.005 in. This layer, which is contaminated with iron, 'then covered with a second layer of the sane alloy which is machined to finish dimensions, leaVirita thickness of 0.010 in.,nr inure. The second layer, it is stated, is protected. from iron -diffusion by the first one, and it is claimed. that no -appreciable amount is present in the outer skin.

Tags

People: W. Davies
Locations: Bradford, Derby, Lincoln, London

comments powered by Disqus