IMPROVEMENTS IN CUTTING SPIRAL BEVELS.
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A Resume of Recently Published Patent Specifications.
-r; AVID BROWN AND SONS, the well-known gear J_J experts, of Huddersfield, in specification No. 254,884 describe certain improvements they have made in connection with the cutting of bevel gears the teeth of which are curved or sDiral.
In the cutting of such gears the cutters describe a circular path, whilst a rolling movement is kept up which represents the rolling of the pinion in relation to the crown wheel.
There is not space here fully to describe the process, but briefly, the improvement seems to lie in the form of cutter employed.
. The left-hand view shows diagrammatically a pinion and crown whecl and the path followed by the cutter while operating on either wheel or pinion. The right-hand view shows the form of cutter used, and it will be noticed that in one case the cutter is single, and cuts the space away from between the teeth, and, owinr to the rolling motion, produces the desired form. In the other ease the cutter straddles the tooth it is forming. The cutters are a counterpart of each other, and by their use it is claimed that more perfect mating of the teeth is ensured.
A New Locknut.
A SIMPLE form of locknut is shown in specification No. 254,970 by D. W. Berlin, of Rasunda, Sweden. A V-shaped groow is formed across the face of the nut, but not extending to the outside. After the nut is tapped, a dent is made on two opposite sides of the nut, as shown. The forming of these dents has the effect of pressing a portion of the interior of the nut inwards, as indicated by the full lines when they deviate from the dotted lines which indicate the major part of the bore. In operation, the nut can be screwed freely on to its bolt until it comes to the part which has been contracted by the denting; after this the nut becomes "spanner-tight" which is claimed to be sufficient to pre-,ent. it from working loose.
It is not easy to see why the V groove should not extend right across the face of the tat, as if it did it could easily be milled, but if formed as shown it would be necessary to form such a groove by forging 'while the nut is hot, which could only be carried out on black nuts..
Another Six-wheeler,
IN SPECIFICATION No. 254,829 the Eagle Engineering Co., of Warwick, and W. Woodward show a simple form of six-wheeler.
They point out that official regulations fix the maximum length of the frame members, and that these regulations seriously restrict the available space for load carrying. By the adoption of their plan, they claim that heavier, bulkier and better-distribufed loads can be carried.
The invention takes the form of a chassis of usual design, but rather shorter, and having the rear wheels at the extreme end of the frame. Slightly in front of the rear axle is a
pivot, not GE the king-pin type, but with its axis horizontal, as shown. Mounted on this pivot is the load-carrying frame, which is provided with a pair of wheels that do not assist in the driving, nor do they steer.
Just behind the cab the upper frame is provided with two cheeks that span the lower frame on each side and which relieve the pivot of stress when turning corners.
By this construction a kind of rigid six-wheeler is formed, the pivot allowing the two axles at the rear to conform to the curvature of the road. As in the rigid six-wheeler, there must be a certain amount of tyre grinding when turning, but, knowing the experience this maker has had in the construction of trailers, etc., we expect that they have not found this an objectionable feature.
An Oiling System for Cranks.
THE J. G. BRILL CO., of Philadelphia, in specification
No. 243,314, describe a means of oiling crankshafts by means of a constantly circulating flow of oil. The upper pipe is the one that leads oil to the main bearings, from which it circulates to the big-end hearings. According to the specifi cation, after lubricating all bearings, the oil returns, as • shown by the arrows, along the lower pipe to the tank. It is claimed that the oil, on its return, brings with it any particles of metal that may have become detached through wear.
An American Spring Drive.
THE INTERNATIONAL MOTOR CO., of America, in specification No. 254,928, show what they call a "shock absorber," or flexible coupling.
The two shafts to be coupled are each provided with a two-arm spider arranged to hold suitable cups to receive buffers of yielding material such as rubber. Apart from its shock-absorbing properties, the device is intended to act as a flexible coupling to unite two shafts that are not in true alignment with each other.
The specificittion states that no rubbing takes place, as any angular motion is compensated for by the " jellying " of the rubber, or what is there called " flow " of such material.
The design bears a strong resemblance to the buffer drive which has been used on the R.C. model Commerear for the last 20 years, the main difference being that a centring spherical joint is used as well as the rubber buffers. Such centring devices have been employed here, but difficulties have arisen owing, to the spherical bearing requiring lubrication, and such lubrication finding its way to the rubber.