US2760522A

US2760522A - Pick motion for looms

Info

Publication number: US2760522A
Application number: US484899A
Authority: US
Inventors: Theodore S Higgins
Original assignee: Draper Corp
Current assignee: Draper Corp
Priority date: 1955-01-31
Filing date: 1955-01-31
Publication date: 1956-08-28
Anticipated expiration: 1973-08-28

Description

Aug. 28, 1956 T. s. HIGGINS PICK MOTION FOR LOOMS Filed Jan. 51, 1955 INVENTOR. THEODORE 5; HIGGlNS ATTORNEY l m; him 714 \v Win; ...1

Unite PICK MOTION FOR LOOMS Application January 31, 1955, Serial No. 484,899

9 Claims. (Cl. 139147) This invention relates to looms for weaving, and, more particularly, to improvements in the picking mechanism by which a shuttle is propelled to and fro in the fly shuttle type of loom.

It is a general object of the invention to devise a pick motion employing cams in which the shock of picking shall-be greatly reduced and in which the steepness of the cams may be greatly lessened without detracting from the force or effectiveness of the pick.

A more specific object is that of providing an effective picking means using cams of relatively easy contour rofated at a high speed so that the surface speed of the cam 'past its follower is much higher than now used with conventicnal equipment.

It is a further object to reduce the shock and noise incidental to picking.

Another object is that of providing a controlled ac- 'cel'era-tion of the shuttle so as to build up velocity with-a cam and follower combination in which contact is maintained between the two rather than by an impact of parts after which the follower leaves the cam.

It is a further object to use more of the cam contour and thus a greater angle of shaft movement for the pick so as to ease the load on the driving gears by distributing it over a greater number of teeth.

Other objects will be apparent from the following disclosure.

Pick motions as commonly employed in the fly shuttle loom comprise cams carried by a cam shaft rotated one revolution for every two picks of the loom and engageable with a follower or pick ball carried on a short arm which is fixed to a pick shaft. Motion from the shaft is 'transmitted to the picker stick and eventually to a shuttle by known means. The speed of the cam shaft is such that the angle of the active picking surface on a e-am for this purpose must be very steep, in fact, so steep that it actually ceases to function as a cam but rather, resembles moreof an impact member striking the pick ball a blow by means "of which the conventional parts are very rapidly accelerated.

As is Well known, the presently used picking means is noisy and contributes heavy vibrational forces to the loom all of which are desirably to be avoided. Parts are rapidly worn and replacements must be made frequently. The pick load reaches a peak at each cycle which is relatively high and identified with a very small angular part of the half revolution of the cam shaft incidental to a pick cycle.

In correcting the above mentioned undesirable characteristics of the prior art, the instant invention contemplates a cam 'or other shaft upon which pick cams are mounted and by which they are rotated at a speed in excess of that of conventional equipment, and means for periodically withdrawing each cam from a position in which it will engage the pick ball or other means for receiving the picking impulse to a position in which it may be rotated idly for one or more turns. Such a cam 2,760,522 Patented Aug. 28,1956

thus has a high angular velocity and two or more times as much of its contour may be effective for picking so that a less steep cam angle and more conventional cam action can be utilized. The curve of acceleration for the shuttle is longer and less abrupt, but actual power delivered to the shuttle and speed of the shuttle itself as it leaves the box at pick can easily be maintained at any value desired.

The invention will be described in detail by reference to a specific embodiment thereof as illustrated in the-accompanying figures of drawing wherein:

Fig. 1 is a front view of a part of a loom-showing the invention applied there-to.

Fig. 2 is an enlarged detail view of one pick motion.

Fig. 3 is a partial section taken at line 33, Fig. 2.

Fig. 4 is a developed view of a cam for withdrawing the pick cam to give intermittent action.

Now referring to Fig. 1, the invention maybe applied to any fly shuttle loom having among other parts,

loomsides

10 and 11, a crankshaft 12 driven by a-motor M, a pinion (not shown) on the shaft of which meshes With a gear 13 on the crankshaft end. A camshaft 14 is in turn driven through any suitable means, for example, a gear 15 fixed to the camshaft and meshing with gear 13 to be driven at a speed ratio of 1:1 or 1:2 or faster. Normally these camshafts are driven at onlyone-half crankshaft speed, 'but the present invention contemplates a speed at least that of the crankshaft and-more-desirably twice that. Of course, any desired speed may be obtained by proper ratio of the driving gears.

Each loomside carries for rotation in the usual bearing brackets pick shafts 16 to each of which is fixed an arm 17 carrying a cam follower or pick ball 18, and a'depending arm 19 to the lower end of which is attached a lug connection 20. This lug connection and lug strap 21 in turn are engaged with a picker stick 22 which is more or less of conventional design and pivotable on any suitable parallel mechanism 23 carried at the outer end of a rock shaft 24. Numerals are mainly applied to the right hand unit and not to the left to simplify the showing and since each is similar although parts may be reversed to function at opposite ends of the loom. Also, all :parts are so designed as to function apart so that first one picking means causes the shuttle 25 to be propelled across the lay 26 and then the other returns it to the original side. As illustrated in Fig. l, the right hand side of the loom has just functioned to pick the shuttle which is shown on its way to the left side.

This picking action is induced by an upward movement of arm 17 swinging shaft 16 and arm 19 so that lug connection 20 pulls the picker stick sharply inwardly of the loom to accelerate the shuttle. According to-the invention herein described, a pick cam means is rotated by shaft 14, but does not affect the arm 17 each time the cam rotates. "Cam 27, better shown in Fig. 3, is adjustably fixed to a disk 28, the hub 29 of which is borne on shaft 14 being constrained to rotate with the shaft by a key or

keys

30, 31. The disk may, however, slide axially of the shaft as permitted by the keys or by splines, and as governed by mechanism to be described.

Cam 27 is clamped to the disk by screws 32, four such being effectively used for the purpose. Adjustment'angularly to time the pick is effected through an adjusting screw 33 threaded through a lug 34 on the disk and bearing against a boss 35 on the cam. The lug 34 projects through an opening in the cam. A nut 36 looks the adjustment in position and once screws 32- have been tightened, the cam and disk are, to all intents and purposes, a unit. The cam is provided with a wider contour at its working part and it's hardened follower engaging face is bevelled so as to bear against the follower over-as wide an area as is practicable.

According to the particular form of the invention shown, the cam makes four revolutions for every pick at its particular side of the loom. Only one of these is made while the cam is aligned for contact with the pick ball 18 while the other three are ineffective. The cam is, therefore, removed axially to a position as at the left side, Fig. 1, in which it may rotate just outside the radius of movement of the arm 17 and follower 18. To accomplish that a barrel cam generally designated by numeral 37 having a groove 38 is used. This barrel cam may slide along the shaft 14 and is free to rotate thereon as driven by gearing including a pinion 39 keyed to shaft 14, gear 40, pinion 41 and gear 42, the latter being a part of or attached to the barrel cam. Gear 40 and pinion 41 are fixed to rotate as a unit and are pivoted on stud 43 which is fast in bracket 44 bolted to loomside 11 or to some other suitable fixed part of the loom.

This bracket also supports a follower 45 rotatable on the end of pin 46, the latter extending into a suitable opening therefor in the bracket. Follower 45 is aligned with and functions within groove 38 so that, since the follower is fixed, the rotation of the barrel cam causes its axial motion according to the contour defined by the cam groove.

As the barrel cam reciprocates axially, the gear 42 moves axially as well and for that reason, pinion 41 is elongated to drive the gear while its axial position varies considerably.

The barrel cam is connected to the hub of the disk 28 by straps 47 and 48 rigidly bolted to that end of the cam hub and having rolls or

followers

49 and 50 at their disk ends which ride within a groove 51 in its hub. Thus the disk and barrel cam are locked together for axial movement, but may rotate independently. For controlling .the cam 27 to make one pick in four revolutions, cam 37 is stepped down to one turn for the same four revolutions. Its groove is actually disposed as shown in the development of Fig. 4, so that as the longer part of the groove is involved with follower 45, the pick cam is pulled inwardly to inactive position and as the shorter, offset part of the groove comes into play, Fig. 2, the pick cam moves to engage pick ball 18 and the shuttle is then picked toward the opposite side of the loom. Two rotations later of cam shaft 14 the same thing happens at the opposite side.

By the conventional picking means now used only about 20 of cam travel is available for picking. This, as above said, means that a most violent cam action is necessary. With the instant means about 80 of cam travel is available for the same purpose. Cam path 38 is laid out accordingly and the steepness and, in fact, the type of cam action for cam 27 is entirely different as a result of this; the acceleration of the pick ball and likewise the shuttle is built up more gradually, but eventually reaches a required velocity within available time limitations. The cam here comes closer to being an eccentric since it need have a contour only slightly removed from a true circle.

If the cam shaft is to be rotated at crankshaft speed so that a cam is active one revolution and inactive the next, the gearing for driving the barrel or control carn should then have a ratio of 2:1 so the cam 37 will then turn once for each two revolutions of the camshaft. Of course, other variations may be used, but the disclosure herein given should serve to show the principles which apply.

By way of illustration, the arm 17 and pick ball 18 are positioned above the rotating cam, but, of course, it may be below as is frequently the case. The pick shaft is then mounted much lower in the loom and arm 19 extends upwardly instead of down.

Normally the gearing from crankshaft to camshaft involves a reduction so that the gear on the former is onehalf the size of that with which it meshes on the camshaft. With such arrangements it has been necessary to drive the crankshaft through another and larger gear to obtain sufficient reduction from the motor. Now gear 13 is large enough to drive it directly from the motor pinion.

Preferably although not necessarily, a casing 52 encloses the entire mechanism, there being an opening for the shaft and also for the arm 17. The latter may be closed by a flexible baffle if desired. This casing may be oil tight so that the parts run in a bath of oil, but in most instances it is preferred that it be a protection against lubricant being thrown outwardly to other parts and against dirt and lint entering. A side or sides may be readily detachable so that the parts may be lubricated with a grease gun or by other means and to service or adjust the mechanism as desired.

Of course, as an alternate form of the invention, it is contemplated that the pick ball may be moved away from the orbit of the cam in such way that the cam may pass the pick ball without affecting it.

While many looms have both a camshaft and a crankshaft, there are looms in which the lay is caused to move in a beat-up path by cam or other connections to a camshaft so that no crankshaft is needed. In such instances the camshaft serves a dual function and, of course, the invention applies to all looms having a shaft by which pick cairn means is caused to function regardless of the added functions that shaft may have.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the invention and the scope of the claims.

I claim:

1. In a loom the combination of a camshaft, means for driving said camshaft, a pick motion including a pick shaft and means carried thereby for receiving a picking impulse, pick cam means carried by said camshaft and rotatable therewith while slidable axially of the shaft to and from a position to engage said means for receiving the picking impulse, and means for moving said pick cam means axially into and from a position to engage said means to receive the picking impulse which comprises a sleeve freely rotatable on said shaft, cam means to move said sleeve axially of the shaft, 21 means connecting said sleeve and pick cam means so that axial movement of one is imparted to the other While relative rotary movement between the two is permitted, and other means for positively rotating the sleeve at a speed different from the speed of rotation of the shaft.

2. In a loom the combination of a crankshaft, a camshaft, means for rotating said camshaft at a speed at least equal to that at which the crankshaft is rotated, a pick motion including a pick shaft and means carried thereby for receiving a picking impulse, pick cam means on said camshaft rotatable therewith While freely slidable axially of the shaft, and means including a speed reducing gear train, a barrel cam carried by the shaft and rotatable by said gear train for moving the pick cam means axially to and from a position to engage the means for receiving the picking impulse.

3. In a loom the combination of a crankshaft, a cam shaft, means for rotating said camshaft at a speed at least equal to that at which the crankshaft is rotated, a pick motion including a pick shaft and means carried thereby for receiving a picking impulse, pick cam means on said camshaft rotatable therewith and engageable with said means for receiving the picking impulse, said pick cam means being rotated at a speed at least twice the speed of said cam shaft, a gear train and means coaxial with and driven by said camshaft through said gear train for preventing contact between said pick cam means and means for receiving the picking impulse at alternate rotations of the cam means.

4. In a loom the combination of a crankshaft, a cam shaft, means for rotating said camshaft at a speed at least equal to that at which the crankshaft is rotated, a pick motion including a pick shaft and means carried thereby for receiving a picking impulse, pick cam means on said camshaft rotatable therewith and engageable with said means for receiving the picking impulse, said pick cam means being rotated at a speed at least twice the speed of said cam shaft, a gear train and means coaxial with and driven by said camshaft through said gear train for so affecting the relative positions of pick cam means and the means for receiving the picking impulse that at alternate picks they are removed from a relationship permitting active contact.

5. In a loom the combination of a crankshaft, a camshaft, means for rotating said camshaft at a speed at least equal to that at which the crankshaft is rotated, a pick motion including a pick shaft and means carried thereby for receiving a picking impulse, pick cam means on said camshaft rotatable therewith while freely slidable axially of the shaft, a barrel type cam slidable on said shaft and connected for axial movement with said pick cam While rotatable independently thereof, a follower in relatively fixed position cooperating with said barrel cam, and means carried on and driven by said shaft for rotating said barrel cam at a speed less than that of the pick cam.

6. In a loom the combination of a crankshaft, a camshaft, means for rotating said camshaft at a speed at least equal to that at which the crankshaft is rotated, a pick motion including a pick shaft and means carried thereby for receiving a picking impulse, pick cam means on said camshaft rotatable therewith while freely slidable axially of the shaft, a barrel type cam with a cam groove slidable along said shaft and means interconnecting said barrel cam and pick cam for movement together along the shaft while permitting unrestrained rotation between the two, a bracket fixed adjacent said barrel cam, a follower carried by the bracket engaged within said groove, and a gear train between said shaft and barrel cam for rotating the cam at a speed less than that of said pick cam.

7. Mechanism as defined in claim 6 wherein said gear train comprises a pinion on said shaft, a gear fixed to the barrel cam and intermediate gears mounted on said bracket, one of which is elongated to drive the barrel cam while it reciprocates axially of the shaft.

8. In a loom the combination of a camshaft, means for rotating said camshaft, a pick motion including a pick shaft and means carried thereby for receiving a picking impulse, a pick cam means on said camshaft rotatable therewith and engageable with said means for receiving the picking impulse, said pick cam means being rotated at a number of revolutions at least equal to the number of picks made by the loom in a given period of time, a gear train and means coaxial with and driven by said camshaft from said gear train for preventing contact between said pick cam means and means for receiving the picking im pulse at spaced rotations of the cam means.

9. In a loom the combination of a camshaft, means for rotating said camshaft, a pick motion including a pick shaft and means carried thereby for receiving a picking impulse, pick cam means on said camshaft rotatable therewith and engageable with said means for receiving the picking impulse, said pick cam means being rotated at a number of revolutions at least equal to the number of picks made by the loom in a given period of time, a gear train and means coaxial with and driven by said camshaft from said gear train for so affecting the relative positions of pick cam means and the means for receiving the picking impulse that at spaced rotations of the cam means they are removed from a relationship permitting active contact.

References Cited in the file of this patent UNITED STATES PATENTS 1,164,094 Hutchins Dec. 14, 1915