US2410718A - Stop motion for knitting machines - Google Patents

Stop motion for knitting machines Download PDF

Info

Publication number
US2410718A
US2410718A US644288A US64428846A US2410718A US 2410718 A US2410718 A US 2410718A US 644288 A US644288 A US 644288A US 64428846 A US64428846 A US 64428846A US 2410718 A US2410718 A US 2410718A
Authority
US
United States
Prior art keywords
arm
switch
casing
stop motion
crank
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US644288A
Inventor
Crawford Alfred
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CRAWFORD MANUFACTURING Co
Original Assignee
CRAWFORD Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by CRAWFORD Manufacturing Co filed Critical CRAWFORD Manufacturing Co
Priority to US644288A priority Critical patent/US2410718A/en
Application granted granted Critical
Publication of US2410718A publication Critical patent/US2410718A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • DTEXTILES; PAPER
    • D04BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04BKNITTING
    • D04B35/00Details of, or auxiliary devices incorporated in, knitting machines, not otherwise provided for
    • D04B35/10Indicating, warning, or safety devices, e.g. stop motions

Description

Nov. 5, 1946. A. CRAWFORD 2,410,718

S TOP MOTION FOR KNITTING. MACHINES Filed Jan. so, 1946 2 Sheets-Sheet; 1.

Nov. 5, 1946. A. CRAWFORD 2,410,713

STOP MOTION FOR KNITTING MACHINES Filed Jan. 50, 1946 2 Sheets-Sheet 2 Patented Nov. 5, 1946 2,410,718 STOP MOTION FOR KNITTING MACHINES Alfred Crawford,

New Brunswick, N. J., assignor to Crawford Manufacturing Company, New Brunswick, N. J a corporation of New Jersey Application January 30, 1946, Serial No. 644,288

4 Claims.

This invention relates to improvements in stop motions for knitting machines and more particularly to improvements specific .to the type of stop motion produced and marketed by the Crawford Manufacturing Company of New Brunswick, New Jersey, whose commercial product is disclosed in general in a prior patent to Alfred Crawford, No. 1,992,860, dated February 26, 1935, while certain details of the device are disclosed ina prior patent to Michael Antonevich, No. 2,257,030, dated September 23, 1941, of which, inv each instance, the Crawford Manufacturing Company isthe assignee exclusively.

In each of the structures disclosed, respectively, in the aforesaid patents, the very uppermost partof the stop motion is in the form of a spider including alarge central hub portion from which a number of arms radiate. In each instance, the outer end of the arm supports a thread controlled device which willoperate to effect stopping of the knitting machine should the knitting thread or yarn become too tight, too loose, or break.

The thread controlled fingers of the entire series carried respectively by the radiating spider arms, operate a common control mechanism housed within the hub of the spider. Thus, in initial installation, it requires that a complete assembly of all the thread controlled mechanisms, including a switch operating element individual to each, and a switch actuating ring common to all, mustbe made before the device as a whole can be adjusted for operation with the knitting to which the stop motion is applied.

In the prior patent to Crawford, aforesaid, it will be noted that there is a second series of thread controlled switches housed in a hollow annular casing located above, but in relatively close proximity to the knitting head of the machine to which the stop motion is applied. These lower switches are subject to becoming fouled by lint, etc., entering through various openings in the annular casing, etc., through which certain elements of the device extend.

The present invention is directed to the provision of an improved type of switch structure adapted to replace both the top switches and the lower switches of the stopmotion which asa whole is disclosed in the aforesaid Crawford patent. Primarily, the new switches are adapted to be completely enclosed in dust-proof casings to prevent entrance of lint and the fouling of the switch mechanism. Furthermore, the construction is such that the switches maybe preassembled and adjusted individually and held in stock for future assembling or as replacements in the stop motions as a whole. The principles upon which .both the top and bottom switches of the present invention are constructed are sub- Fig. 4 is a side elevation, partly in section, of

the upper switch unit, with thecover plate ;re-, moved;

Fig. 5 is a transverse section taken on the line 5-4, Fig. 4.; and

Fig. 6 is a transverse section taken on the.

line i: -6, Fig. 4.

The new bottom switch, as shown in Figs. 1,

2, and 3 of theattached drawings, includes a dust-proof casing I in which is mounted a transverse shaft 2 having a sweep arm or feeler wire 4 secured to one end thereof outside the casing I, The free end of the sweep wire 4 is provided with a thread. eye 5 operating between fixed thread eyes 6, 6, through all three of which extends the knitting thread a: on its way to the knitting head of the machine.

Within the casing l the shaft 2 is provided with a crank which bears against a cam surface 8 on a long arm 9 of a bell crank lever which is pivoted at Ill within the casing l. The short arm ll of the bell crank lever has attached thereto one end of the tension spring l2, the opposite end of which is soldered or otherwise secured to a block [3 which is slidably mounted in the casing I, and is adjustable by a screw M from outside the casing I. Obviously by adjust-v ing the screw [4 any desired degree of tension may be placed on the sweep arm 4, constantly tendin to swing it in the directionv of the arrow in Fig. 2, whereby more or less tension is applied to the thread r between the fixed guides v6, 6. Due to the relation between the long and short arms of the bell crank lever, very little axial extension of the spring 12 is required, and this provides uniform tension on the outer end of the sweep arm at all times through a rather long movement of the outer end of the sweep arm.

Should the yarn a: break, or become excessively slack at 01' near the knitting head, the free end 5 ofthe sweep arm 4 will be released and the spring l2 acting through the bell-crank ll- 9 will cause the cam face 8 of the long arm 9 to force the crank I downwardly, fromits full line,

position shown in Fig. 2, 'to'its broken line position shown in said figure, to permit the tip 9a of the arm 9 to make electrical contact with a resilient contact I5.

The weight of the sweep arm 4 is substantially counterbalanced by an off-center weight I2a applied to the protruding end of the operatin shaft 2, in order to make the action of the tension spring I2 more sensitive.

The contact I5 is secured by a shouldered rivet I6 to an insulating block II, secured in the box I by a screw I8. The larger diametered portion I9 of the rivet I6 passes through an oversized hole in the end wall of the box I and is connected by a screw 22 to an angle strap 2|, which in turn is electrically connected to a buss bar 23 forming part of one side of the circuit for the electric knock-off mechanism (not shown) of the stop motion, the box I, etc, being included in the second side of the circuit.

The boxes I are each provided with a slotted lug 24 adapted to be adjustably bolted to a supporting ring 25, similar to a corresponding ring of the Crawford patent aforesaid.

Obviously the switch mechanisms may be completely assembled in the boxes I and adjusted ready to be applied subsequently to the supporting ring 25 on machines having any prevailing number of yarn feeds, with one switch assembly for each feed. All the adjustment required, after the boxes I are in place, would be to bend the sweep wires 4 to bring the eye 5 in proper relation to the fixed eyes 6, 6.

The eyes 6, 6 are supported by arms 26, like the corresponding arms of the Crawford patent aforesaid, and these arms may be attached to covers 21 of the boxes I durin remote assembly of the switch mechanisms therein, or the arms may be connected directly to the boxes I or to the supporting ring 25, as desired.

In the top switch shown in Figs. 4, 5, and 6 of the drawings, all of the mechanism is confined in the boxes Ia and these boxes are separately connected to the spider arms I I6 of the aforesaid Crawford patent or the corresponding arms of the aforesaid Antonevich patent, thus eliminating the two coaxial shafts disclosed in said patents and which extend longitudinally of each spider arm; and also eliminating all of the switch mechanisms confined in the hubs from which the spider arms project.

These upper switch mechanisms are substantially the same as the lower switch mechanisms previously described as being confined in the boxes I, and the same reference characters are here now employed. However, instead of the operating shaft, as the shaft 2 in the lower switch mechanism being parallel to the pivot l0 for the bell crank B-I I, the operating shaft 2a of the upper switch mechanism projects into the casing Ia through one end wall thereof, at right angles to the axis of the pivot Illa of the bell crank 9a II a, therefore the long arm 9a is provided with a right angle extension 91) against which the crank Ia of the shaft 2a bears. The sweep arm 4a is normally urged in the direction of the arrow in Fig. 6 by a resiliently mounted arm 28, which corresponds to the same kind of arm as shown in the Antonevich patent aforesaid.

If the yarn a: breaks or becomes excessively slack, the resiliently mounted arm 28 moves the sweep arm 4a upwardly turning the shaft 2a and crank 1a accordingly, permittin the right angular extension 9b of the long arm 9a of the bell crank 9a-I Ia under the influence of the spring I2 and weight I2a, to engage the resilient contact I5a, closing the circuit between the buss bar 23a and the casing Ia to actuate the electric knock-off of the stop motion.

If the yarn should become excessively taut, the sweep arm do will be moved downwardly turning the shaft 2a and its crank 1a accordingly and forcing the right angular extension 9b of the bell crank 9a-IIa into contact with a second resilient contact I5b which also closes the circuit for actuating the electric knock-off of the stop motion.

It will be understood that the feeler 4 or 4a, as the case may be, is extremely sensitive to fluctuations in the tension of the running yarn 2:. It also detects the presence or absence of a running yarn and in any instance of unnormal eventuality effects the proper reactions in the apparatus as a whole to stop the machine.

The bell-crank lever, which in effect constitutes a rotary switch element having one portion adapted to engage the electric terminal element I5 is extremely sensitive, and this sensitivity is maintained uniform by reason of the axis of the tension spring I2 being substantially tangent to the are described by the point of attachment of the one end of the spring I2 with the short arm I I of the bell-crank lever, due to the fact that such point travels but a very short distance and not sufficient to produce any substantial elongation of the spring I2.

I claim:

1. A switch structure for electric stop motions for knitting machines and the like, comprising a closed casing, an operating shaft pivoted in and having one portion projecting outside said casing, a bell-crank lever pivoted and confined within said casing, a tension spring operatively eonnected to one arm of said belLcrank lever and confined within said casing, an electric terminal element within said casing and engageable by a second arm of said bell-crank lever, a crank on the portion of the operatin shaft disposed within said casing and engageable with one of said arms, and a thread engaging sweep arm secured to that portion of the operating shaft disposed outside said casing.

2. A structure according to claim 1, characterized by the bell-crank having a long arm and a short arm, with the tension spring connected to said short arm and the crank of the operating shaft engageable with said long arm.

3. A structure accordin to claim 1 characterized by the tension spring being partially opposed by an eccentric Weight on the protruding portion of the operating shaft and partially counterbalancing the weight of the sweep arm, to make the tension spring more sensitive to fluctuations in the tension of the knitting yarn.

4. In a switch structure, the combination of a substantially fixed electric terminal element, a relatively rotatable switch element adapted to have one portion thereof engageable with said terminal element and comprising a bell-crank lever including a short arm and a relatively long arm, a tension spring operatively connected to said short arm with the axis of said spring substantially tangent to the arc of travel of the point of attachment of one end of the spring to said short arm to maintain the applied tension of said spring uniformly sensitive, and a feeler element engageable with and adapted to actuate said switch element into contact with said terminal element by overcoming said tension of said spring.

ALFRED CRAWFORD.

US644288A 1946-01-30 1946-01-30 Stop motion for knitting machines Expired - Lifetime US2410718A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US644288A US2410718A (en) 1946-01-30 1946-01-30 Stop motion for knitting machines

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US644288A US2410718A (en) 1946-01-30 1946-01-30 Stop motion for knitting machines

Publications (1)

Publication Number Publication Date
US2410718A true US2410718A (en) 1946-11-05

Family

ID=24584259

Family Applications (1)

Application Number Title Priority Date Filing Date
US644288A Expired - Lifetime US2410718A (en) 1946-01-30 1946-01-30 Stop motion for knitting machines

Country Status (1)

Country Link
US (1) US2410718A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2747039A (en) * 1953-06-01 1956-05-22 Stop Motion Devices Corp Stop-motion devices relating to sewing machine bobbins
US2747040A (en) * 1953-06-01 1956-05-22 Stop Motion Devices Corp Stop-motion switch for sewing machine bobbin thread
US2930861A (en) * 1958-11-12 1960-03-29 Morat Kg Franz Thread controlling device for electrically operated knitting and hosiery machines
US3239618A (en) * 1962-02-02 1966-03-08 Driam Sa Apparatus for guiding strip stock
US3848434A (en) * 1973-03-05 1974-11-19 Control Switch Inc Yarn detector switch-lower
US4271687A (en) * 1978-08-01 1981-06-09 Memminger Gmbh Rapid maintenance thread or yarn supply apparatus, particularly for circular knitting machines

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2747039A (en) * 1953-06-01 1956-05-22 Stop Motion Devices Corp Stop-motion devices relating to sewing machine bobbins
US2747040A (en) * 1953-06-01 1956-05-22 Stop Motion Devices Corp Stop-motion switch for sewing machine bobbin thread
US2930861A (en) * 1958-11-12 1960-03-29 Morat Kg Franz Thread controlling device for electrically operated knitting and hosiery machines
US3239618A (en) * 1962-02-02 1966-03-08 Driam Sa Apparatus for guiding strip stock
US3848434A (en) * 1973-03-05 1974-11-19 Control Switch Inc Yarn detector switch-lower
US4271687A (en) * 1978-08-01 1981-06-09 Memminger Gmbh Rapid maintenance thread or yarn supply apparatus, particularly for circular knitting machines

Similar Documents

Publication Publication Date Title
US2397153A (en) Adjustable yarn tension device
US3688958A (en) Device for sensing thread passage to control machine operation
US2233483A (en) Supervising filamentary material
US2438365A (en) Stop means for textile apparatus and the like
GB872598A (en) Improvements in or relating to automatic thread winding machines
US2227355A (en) Feeding apparatus
US1178566A (en) Antitwisting device.
US2202323A (en) Weft tension and loom stopping device
US2626765A (en) Wire guiding device
US2655781A (en) Apparatus for imparting false twist to yarn
CZ285998B6 (en) Circular loom
CN102888707B (en) Yarn guiding device for computerized flat knitter with function of yarn knot alarm
US2698590A (en) Thread tension regulator for sewing machines
US3802228A (en) Mounting means for positive yarn feeding device and stop motion on a circular knitting machine
US2227356A (en) Method of and means for changing the speed of electric motors for various purposes
US3247662A (en) Device for checking the run of the thread in a draw twisting frame or the like
US2963890A (en) Electrical stop motion for knitting machines
US2719338A (en) Coilers for textile fibers
US1581093A (en) Yarn furnishing and controlling mechanism for knitting machines
US1671976A (en) Strand-tension-control mechanism
US3256395A (en) Operator safety device for rotating machinery parts
US1921446A (en) Automatic charging means for centrifugal extractors
US2257037A (en) Stop motion device for knitting machines
US1111500A (en) Thread-tension device.
US1992716A (en) Automatic weighing machine-discharge regulating type