US2003766A - Safety device fob straight knitting - Google Patents

Description

June 4, 1935. M. ZWICKY SAFETY DEVICE FOR STRAIGHT KNITTING MACHINES Filed April '7, 1933 5 Sheets-Sheet 1 with Z QZ 101' gzr BY Q 1 SAFETY DEVICE FOR STRAIGHT KNITTING MACHINES Filed April '7, 1935 3 Sheets-Sheet 2 IN VENTOR:

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SAFETY DEVICE FOR STRAIGHT KNITTING MACHINES Filed April '7, 1935 3 SheetsSheet 3 W ATTORN Patented June 4, 1935 SAFETY DEVICE FOR STRAIGHT KNITTING MACHINES Melchior Zwicky, Berkshire Heights, Pat, assignor to Textile Machine Works, Wyomissing,

Pa., a corporation of Pennsylvania Application April 7, 1933, Serial No. 664,866

may cause breakage of one or the otherof the coulier rollers or other parts, resulting in shutdown of the machine for the repair or replacement of the broken parts.

An important object of the invention, therefore, is to prevent the transmission of power to the operating parts of the knitting machine when jamming of any of the parts has occurred, or under conditions of overload due to accident or other causes, or in case of stoppage of the machine where any further movement of the 2 Claims.

This invention relates to knitting machines of the straight or full fashioned type, and more particularly to safety devices for use with the driving mechanism thereof.

An important consideration in machines of this type is the transmission of motive power to the operating parts of the machine. Since the machine is generally composed of a multiplicity of sections, the driving force must be properly distributed in order to avoid multiplication of the torsional stress upon the cam shaft with consequent irregularity of movement of the operating parts in different sections as well as vibrations tending to upset the requisite accurate alignment of the operating parts throughout.

To eliminate to as high a degree as possible the objectionable effects of the torsional strain on the various shafts and the coincident vibrations accompanying such strain, as well as to decrease the size and weight of the required shafts and other parts, it is important that the knitting machine be arranged so that the power is uniformly and evenly applied to the operating parts. To this end the power is desirably first transmitted from the usual motor directly to the handwheel shaft, then to a drive shaft and from the drive shaft to the main cam shaft. This action results in a very flexible application of the power to the operative parts. v

The above-mentioned structure results in a uniform and satisfactory operation of the knitting machine, but it is, nevertheless, desirable to provide, as part thereof, certain safeguards .against damage caused by jamming of parts of the'machine, and to prevent excessive overload of the drive shaft at any time, from accident or other cause.

The very slight clearances between certain parts of the machine increase the possibility of accident, which may be serious if not arrested in time. For instance, if the catch bar should fall behind and jam the sinkers, and the power is not instantly cut off, a costly sinker head smash would result. Also, the jacks which push the sinkers forward during the loop forming operation may become stuck due to improper lubrication or other cause, which would lead to a jam or serious breakdown if the machine were allowed to run. The narrowing machine, and various other attachments and devices forming part of the knitting machine are also subject to disorganization to a greater or lesser degree. Furthermore, the mere starting of the machine when more particularly pointed out in the claims. cold is sometimes accompanied by sticking of the In the drawings: various friction boxes on the friction rod. This Figure 1 is a cross sectional view of a full to prevent the too sudden application of power to the driven parts when starting the machine.

Another object of the invention is to enable the motor to be operatively connected to the handwheel shaft or any other suitable shaft bya frictional safety coupling which will transmit power gradually to the driven shaft in starting, which will aiford a substantially rigid and firm connection without "undesirable slippage during normal operation, and which will act to render the driving means ineffective to operate the machine in case of accident or jamming of any kind having a tendency to render anypart of the machine inoperative. v

Another object of the invention is to provide a coupling or connection adapted to function as a safety device between axially rotatable drive transmitting and driven elements, the safety coupling being readily adjustable to create the desired pressure to transmit the motor load as quickly or as gradually as may be desired when starting the machine, and also to take up wear on the friction elements. Still other objects are to make the safety coupling of few parts, self contained, and of simple balanced construction so that it may be disassembled with facility for cleaning, repair or replacement; to make the coupling of small size andlight weight so that it will not add unnecessarily to the inertia of the handwheel or other shaft; and to construct the coupling so that it will 'at all times be positive in its action, and -so that it will not generate excessive heat.

With these and other objects in view, which will become apparent from the following detailed description of the illustrative embodiment of the invention shown in the accompanying drawings, the invention resides in the elements of construction, mechanisms and combination of parts in cooperative relationship, as hereinafter operating parts would be detrimental; and also fashioned knitting machine embodying the invention, tak'n along the line i-| of Fig. 2;

Fig. 2 is a partial front view of the machine illustrated in Fig 1;

Fig. 3 is a detail front view, partly in section, of the safety coupling in its ,operative position on the handwheel shaft;

Fig. 4 is a side view, partly broken away, through the safety coupling, as viewed from the left hand side of Fig 3;

Fig. 5 is a detail sectional view through the pressure plate and its follower disc, illustrating the arrangement of one of the spring pressure devices; and

Fig. 6 is a perspective illustration of the parts of the safety coupling in disassembled relationship.

Only those parts of a straight knitting maother parts and mechanisms and their manner of operation being well known in the art, as shown and described in detail in the Reading Full Fashioned Knitting Machine catalogue, copyrighted 1929, and published by the Textile Machine Works, Reading, Pennsylvania.

The knitting machine In in this instance is operated by an electric motor I i which is mounted on a rigid base I2 provided on the machine frame I3. The motor II is connected directly to the handwheel shaft II by means of a chain l5 passing over a small sprocket IS on the motor shaft and a large sprocket H on the handwheel shaft, the sprocket 11 forming part of the safety connection hereinafter described.

The handwheel shaft ll, in turn, is connected to an intermediate or drive shaft I 8 by means of a second chain l9 passing over small and large sprockets 20 and 2| provided on the hand wheel and the handwheel shaft affording hand control of the machine as required and at the same time overcoming any irregularities of cam shaft motion by its customary flywheel effect.

The gearing of the drive shaft l8 to the cam shaft 22 is preferably arranged to most effectively distribute the operating strains, the reduction of the gearing connection as well as the various chain and sprocket connections being calculated to eliminate, so far as possible, torsionalstrain as well as vibrating effects.

' As a relief means in case of excessive overload due to jamming, breakdown or otherwise, and as l a means for eliminating the sudden application of power to the machine, with its consequent strain on the motor, the chains, and other working parts, the invention includes, in the driving connection between the motor H and handwheel shaft I4, a safety coupling construction, indicated generally at 23, and including as part thereof the drivinggear or sprocket I! which surrounds the handwheel shaft.

This coupling 23 includes a cylindrical hub 26, Figs. 3 to 6, having an annular flange portion 21, and being secured to the handwheel shaft I by a key 28. This hub may be located at any suitable point along the handwheel shaft and is here shown, for, better stability, adjacent to oneof the bearings 29 provided for the shaft 54. The gear i1 includes an inner disc or web portion 30, of less thickness than its toothed portion, thereby providing annular recesses 30' and 30" at opposite sides. The web 30 also has an open central portion surrounding the hub 26, adjacent to the inner surface of the annular flange 21, which flange is positioned in the recessed portion 30 and is separated from the flange 30 by a friction disc 3!, of leather, fiber, asbestos, fabric or other suitable material. The hub 26 is provided with a threaded portion 32 to receive an annular pressure plate. This plate 33 is arranged to cooperate with an annular frictional contact disc 34 at its inner side adjacent to the disc 30 of gear ii, the disc 3d fitting the recess 30" of the web (it, and a second friction disc 35, of leather or the like, being interposed between the web 3d and disc 33. As seen in detail in Figs. 3 and 5, the pressure plate 33 is provided wtih a plurality of small but relatively powerful compression springs 36, so that the coupling 25 will positively drive the various mechanisms of the'machine, but will permit slippage in the event of jamming of the mechanisms and thus prevent sinker smashes, injury to the coulier motion, and damage to various other parts of the machine.

In the form shown, there are eight compression springs arranged equidistantly around the inner surface of the plate 33, each of the springs fitting in a shallow recess 31. The contact disc 34 is provided with a plurality of recesses 38 complementary to the recesses 31 and into which the springs 36 extend. To facilitate assembly of the pressure plate 33 and disc 34, each of the springs 36 is secured at the base of its recess 3'! by means of a small screw 39. Also, to cause the contact disc 34 to follow the pressure plate 33 when the latter is threaded on the hub 26, the contact disc is provided with a lug III which is receivable in a locking recess 4! extending across the outer periphery of the plate 33.

It will be apparent that the friction between the parts of the slip coupling 25 depends directly on the pressure applied by the springs 36, which pressure may be varied by changing the position of the pressure plate 33 on the hub 26. The

total depth of the complementary recesses 31 and 38 is sufficient to accommodate the springs under full compression, with the plate 33 and disc 34 practically in contact and with thegear l'l flrmlv held in place between the frictional members under a condition of minimumrpermissible slip- In practice, however, the pressure plate 33 ispreferably screwed down to such a point that there is suflicient load or axial force applied to the driving gear I! to allow the full power of the motor to be transmitted to the machine after the gear has slipped a certain amount.

Thus, when the starting switch of the motor is operated, the machine is not suddenly started at full speed. It is brought to full speed gradually, because of the steady increase in friction between the frictional members and the gear l1;

and thus the starting action .is smooth and free from strain on the various machine parts, which is of considerable importance to the life of the machine as well as to the life of the driving motor.

conditions. For instance, if the friction boxes 42,

aooavee in their travel on the splicing shaft or friction rod 63, are so tight as to cause excessive strain on the drive, especially when the cam rollers may be traversing the high points of the cams, the gear H will slip around the hub 23 and thus prevent damage to the relatively costly parts of the coulier motion. The same slippage will occur in the event of a sinker head smash, a coulier motion jam, or any other failure of operating parts of the machine which, as a first incident, imposes a certain additional strain on the drive. The mechanism furnishes protection to the machine and motor in all cases where the load becomes greater than normal for any reason, and in cases of stoppage where any further movement of the separating parts would be detrimental to the machine.

The extent of the slippage afiorded by the safety device may be adjusted to suit any conditions by appropriately setting the threaded pressure plate 33. When set in a fixed position of adjustment, the pressure plate may be secured in such position by means of the set screw 44 which extends through the side of the pressure plate into engagement with the hub 26. The outer rim of the pressure plate may be provided with a plurality of holes 45 for reception of a pin or other tool to afford a grip for the operator in turning the pressure plate to tighten or loosen the same.

The straight full fashioned knitting machine as illustrated includes a convenient catch bar 48, needle bar 41, narrowing machine 48, sinker head 49 and the usual other parts.

Of course, the device shown and described can be changed and modified in various ways, and adapted for other similar purposes without departing from the invention herein set forth and hereinafter claimed.

ments, a member on the hand-wheel shaft fixed thereto, a drive shaft, a cam shaft, means providing a reduced-gear-ratio connectionfrom the drive shaft to the cam shaft, a second member fixed to the drive shaft, means operatively connecting said members, and a reverse-turning friction-slip connector between said second element and. the hand-wheel shaft normally providing a positive connection between the motive shaft and the drive shaft but responsive to greater driving force by the motive shaft than normally required by the mechanism to cause damped relative slip between portions of the connector in one direction and responsive to excessive opposition by the mechanism to retardation by a reduction of the driving force of the motive shaft to cause damped relative slip between said portions in the opposite direction.

2. A knitting machine comprising knitting mechanism, av motor, a sprocket wheel fixed to the motor shaft, a hand-wheel shaft, a sprocket wheel on the hand-wheel shaft, a chain operatively connecting said sprocket wheels, a second sprocket wheel on the handwheel shaft fixed thereto, a drive shaft, a cam shaft, means providing a reduced-gear-ratio connection from the drive shaft to the cam shaft, a sprocket wheel fixed to the drive shaft, a chain operatively connecting the drive-shaft sprocket wheel to said fixed hand-wheel sprocket wheel, and a reverseturning friction-slip connector between said first hand-wheel shaft sprocket wheel and the handwheel shaft normally providing a positive connection between the motor and the drive shaft but responsive to greater driving force by the motor than normally required by the mechanism to cause damped relative slip between elements of the connector in one direction and responsive to excessive opposition by the mechanism to retardation by a reduction of the driving force of the motor to cause damped relative slip between. said elements in the opposite direction.

, MELCHIOR ZWICKY.

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