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THE

London

JOURNAL OF ARTS AND SCIENCES.

No. XLVI.

[SECOND SERIES.]

Recent Patents.

To JOHN BLACKWELL and THOMAS ALCOCK, both of Claines, in the county of Worcester, machine makers and bobbin-net manufacturers, for their having invented or found out certain improvements in machines or machinery for making lace, commonly called bobbinnet.-[Sealed 13th January, 1831.]

THESE improvements apply to that particular kind or construction of machinery for making lace, commonly called or known by the name of the Lever's principle, which machines are by the Patentees intended to be worked by the agency of a revolving shaft, driven by the hands of the workman, or by any other suitable rotatory power.

The improvements consist in the following contrivances, (viz.) first, a new method of working the landing bars of the machine, by means of certain vibrating levers, and connecting rods actuated by a revolving cam, or excentric roller; or a sort of zigzag or excentric groove, formed in the face of a wheel or

VOL. VIII.-SECOND SERIES.

2 A

revolving plate: and, secondly, a new method of working the dividing bars or pusher bars, by means of compound levers on the lazy tongs principle, which are actuated by a revolving cam, 'connected to the driving part of the machine. These objects will be fully understood by every person conversant with the construction and operation of the Lever's Machines.

To render these contrivances perfectly evident, the Patentees have subjoined drawings to their specification, exhibiting their inventions in several figures, shewing the connection of the new and the old parts, and the manner in which they act together.

Plate VIII. fig. 1, is the right hand end elevation of a Lever's machine, with the improvements adapted thereto. Fig. 2, is a vertical section, taken transversely through the machine, at about two feet from the right hand end.

The several letters of reference indicating the same parts of the machine in all the figures; a, a, are two short axles, mounted on standards on the front parts of the wood frame, towards the end of the machine; to these axles, which are concentric with each other, the driving handle is attached, and by the rotation of these short axles, all the movements of the machine are effected. At the outer extremity of each of the short axles, a, a, a toothed wheel, b, b, is affixed; which respectively take into larger toothed wheels, c, c, upon the ends of the main shaft d, d; this axle d, extends horizontally along the whole length of the machine; it is therefore by the connection of this toothed gear that this main shaft is driven.

Towards the right hand end of the main shaft, near its extremity, the wheel e, with the excentric or zigzag groove is affixed, for the purpose of working the landing bars as above said. This wheel is best seen in the end view, fig. 1. Contiguous to the zigzag wheel, a vertical lever f, is mounted upon a fulcrum pivot g, which enables it to vibrate. In the side of this lever, a pin is fixed, which carries a friction roller h, that

works in the excentric or zigzag groove of the wheel e, and consequently as the wheel goes round, the lever f, vibrates to and fro. At the upper extremity of the lever f, a short rod i, connects the said lever to the crank arm j, fixed on the end of a horizontal shaft k, which extends nearly half way along the back part of the machine. At the reverse end of this shaft k, another crank arm l, is fixed, seen in the section, fig. 2.; which, by means of a rod m, is connected to the back landing bar n, (that and the front landing bar being connected together by the ordinary goose-necked tackle.) Hence it will be perceived, that the vibrations of the lever f, actuated by the zigzag grooved wheel e, give those successive movements to the landing bars, which in ordinary Lever's machine are effected by the workman raising the handles affixed to the front landing bars; the object and effect of which is so well understood, that no further explanation is deemed necessary.

Upon the main shaft d, near the centre of the machine, the cam or excentric roller o, is fixed; see the section fig. 2. On the periphery of which a tooth ≈, extending from the under part of a lever P, is intended to work as the cam goes round; this is for the purpose of moving the pusher bars, which divide the bobbin carriages, after every fourth stroke of the landing bars; an operation which, in ordinary Lever's machine is performed by the foot of the workman pressed upon a treadle below. From the acting extremity of the lever p, two rods or arms 7, 9, extend, and at their upper ends are jointed to bent levers r, r, r, r, which have their fulcrums 8, s, on the same axles as the pusher bars t, t. The pusher bars necessarily rise and fall with the landing bars, as in ordinary Lever's machines, but it is only after every fourth stroke of the landing bars, that the pushers are to be brought into operation. This is effected when the elevated part of the cam o, comes round as shewn in fig. 2, at which time the lever p, is raised, and with it the rods q, q, which expand the joints at the tails of the bent levers r, r, and cause their ends at u, upper И, to press against

the backs of the pusher bars, and force the pushers in: by which means the carriages are divided. This takes place at the time that the landing bars are finishing their fourth stroke.

The particular form in which we recommend the cam o, to be made, is shown in fig. 3. When the tooth ≈, of the lever p, has risen to the highest point of the cam o, it passes down the first short inclined plane, for the purpose of bringing the ends น, น, of the levers z, z, gently into contact with the pusher bars, in order to avoid concussion; and when the ends of the levers have been thus brought into contact with the pusher bars, as the tooth ≈, travels upon the small concentric segment of the cam, the joints of the levers q, r, remain nearly stationary, and the pushers are pressed in to divide the carriages by the closing of the landing bars.

At this time the two catch bars v, v, falling into the ears of the bobbin carriage, for the purpose of locking them, as it is commonly called, it is necessary to ease its descent, in order to prevent concussion, which we do by the employment of a small apparatus, acting under each of the catch bars, as shewn at w, w, fig. 2, which resembles a pair of pliers or the bills of a duck. The lower chap is fixed to its standard, the upper one opens upon a joint, having a lever tail with a helical spring, acting to keep the chaps open; one of each of these apparatus are mounted upon each of the pusher bars, and when the pushers are pressed in to divide the carriages, the nose of each of these pliers are carried under the catch bars, and when the catch bars fall as above said, the upper chaps of the open bills receive them, and allow of their descending gently by the resistance of the springs; and then, by resting upon the closed bills, are prevented from falling upon the pushers, which lie under them. When the bills w, w, have by these means become closed, the time has arrived for the tooth, to pass down the second inclined plane of the cam o, which causes the joints of the levers q, r, to descend, and allow of the pusher bars