A Powerful Automatic Trailer Brake.
Page 24
If you've noticed an error in this article please click here to report it so we can fix it.
The necessity for efficient brakes on trailers drawn by motor or other vehicles has many times been demonstrated in hilly districts, and the recent unfortunate accident, near Bristol, has once more brought the question into prominence, Charles Burrell and Sons, Limited, of Thetford, has given more than passing consideration to this important subject, and the outcome of this company's labour in that direction may be seen on the trailer which is now being hauled round the country by the Burrell tractor (1158) in the R.A.C. trials. There are so many points of virtue in this trailer-brake arrangement, that we feel sure our readers will appreciate a description of its construction. The illustration now reproduced below is frorn a drawing which has been kindly supplied to us through Mr. F. J. Wilson, the company's general and works manager : the simplicity of the arrangement makes the drawing almost self-explanatory. The drawbar eye-bolts (A) slide in guides which are attached to the trailer fore-carriage. When the trailer is being hauled by the tractor, the drawbar eye-bolts take the hauling effort, and transmit itthrough the helical springs (B) to the fore-carriage. So long as the tractor continues to pull, the springs (B) are compressed, but, as soon as the trailer begins to run faster than the tractor, the springs pull back the drawbar eye-bolts, and take up the slack between the guide-plates (C) and the brake-lever (D). Any further increase in the speed of the trailer, or any check in the speed of the tractor, serves to force the brake-blocks into close frictional contact with the leading-wheel tires. It will be seen that any movement of B, in the direction of the arrow (E), must cause the levers (ID) to turn on their fulcrums (F), and, in doing so, they place the lower brake-rods (G) in tension, thus pulling on the after brake-blocks, and pushing on the front brake-blocks.
Ample provision is made for adjustment in the rods (G), but so far, in the trials, only a single adjustment has been necessary. The fitting of these brakes on the trailer attached to I-158 is a very workmanlike job, and the ample pro_ portions of the parts, as well as the absence of keys or keyedon levers, are amongst the many points which make for success. Simplicity and strength are the most essential features in the design of all road vehicles, and we are of opinion that, were all trailers fitted with some such automatic brake as the one here described, there would be few cases like the one we recorded in our pages a fortnight ago.