Thill-coup′ling.
A device for fastening the shafts to the fore-axle.
The ordinary mode of coupling (
a) is by means of a screw-bolt to a clip on the fore-axle.
This wears loose and rattles: hence inventions have been brought forward to improve the mode of coupling.
Many patented contrivances, as
b, depend upon the insertion of a plug behind the pin of the thill, forcing in forward into the hook which is attached to the clip.
c consists of a key and spring-latch as a substitute for the screw-bolt, and occupying a similar position, without special adaptation of the other parts.
d is Bridget's coupling.
The set-screw beneath the socketplate and elastic pad raises the thill-iron against its pivotal pin and prevents rattling.
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Thill-couplings. |
e. The thill-iron is swiveled by a cross-bolt in the head of a pin, which is set in a vertical socket in front of the axle-clip, and is clamped by a set-screw.
f has conical surfaces on the bolt and its socket, which bear against the sides of the thill-iron and prevent rattling.
g is
McDermott's: between the jaws of the coupling is a bushing of anti-friction metal provided with a flange, leaving an opening between it and the lug, and with a tubular projection or socket, whereby dirt will find no lodgment and rattling be prevented.
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h. The clamp-hook or convex-headed cap is situated between the branches of the forked thill-iron, and forms part of a bolt which is secured in the jack by a nut.
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Thill-couplings. |
i. An open ring bushing is placed around the bolt, and the loop of the thill-iron is bent around the bushing, which may be of raw hide.
The end of the iron is bent around and traversed by a temper bolt.
j. The head of the thill-iron has a recess opening into the hole through which the bolt passes; in this recess is a friction-plate, which is pressed against the bolt by a set-screw to prevent rattling.
k. The thill-hook is placed in the clip, and the bolt inserted The bolt, being turned half a revolution, brings the eccentric pin
c against the thill-book, and forces the latter against an elastic pad
e in front of the clip The working faces
a a′ of the bolt turn in the eyes of the clip, as does also the collar
h of the nut g, which prevents the return motion of the bolt.
