Fly Shuttle Loom And Parts Thereof

Abstract

A fly shuttle loom is silenced by replacing metal parts with an elastomer, such as polyurethane. The reduction in noise is partly due to absorbing shock from elements by the elastomer and partly, in fact in some cases mainly, by insulating the frame of the loom from the source of vibration so that it does not radiate noise. The greatest noise is in the shuttle box at each end of the loom. The back box plate, the bottom of the box, and the sides of the picker stick are lined with the elastomer. The power block of the picker stick, the block for the pick shaft, and the pick ball are formed of molded elastomer. A foamed elastomer is glued on the one of the straps of the check strap.

Description

BACKGROUND OF THE INVENTION

Fly shuttle looms in which the shuttle is flown by a picker stick at each end and at the end of its trajectory is braked in a box by pivoted spring loaded sides. Deceleration of the shuttle is completed when the shuttle strikes the end of the picker stick and forces it against check straps or other restraining means. The elements are, of course, duplicated on both sides. The box has a metal lay end plate bolted to the lay beam and a box plate which further guides the shuttle into the box.

The picker sticks are actuated by a pick shaft on each side of the loom, through a pick ball which is the cam follower of a cam which causes the pick shaft to oscillate through an arc and which is driven in synchronism with the mechanism for producing sheds from the yarn warps. At the ends of the pick shafts there are metal blocks, called "pick shaft boxes," bolted to the frame of the loom and in which the pick shaft is journaled at each end. An arm where the shaft passes behind each picker stick is connected to the picker stick by a lug strap and a metal power block which is fastened to each picker stick by U-bolts.

At the top of each picker stick there are check straps or other declerating means when the picker stick is rapidly returned to its extreme position.

The parts of the loom which have been described above are the main sources of noise, which is so great that in many cases workers suffer serious hearing loss as in a room full of fly shuttle looms the noise usually exceeds 100 decibels. More stringent noise control laws in many states and workmen's compensation claims for hearing damages on the part of workmen has made the noise of a fly shuttle loom a serious economic problem. It should be noted that it is not just the impacts of the various elements which are involved. There is also the fact that the sound is transferred to the metal connections, then to the loom frame, which radiates it more strongly. It is with an improved shuttle loom and improved parts thereof that the present invention deals.

SUMMARY OF THE INVENTION

The present invention reduces the noise of fly shuttle looms in a room by at least about 10 decibels, and when the loom is perfectly adjusted, the reduction may be as high as 15 decibels. This is effected by replacing a number of parts with parts molded of elastomers, such as polyurethane, and by lining certain of the metal parts with an elastomer lining. The lining and the molded plastic elements which replace certain metal elements not only reduce noise from primary blows but also serve to insulate the noise from the metal frame so that there is much less radiation. The changed members or modified members will be described without distinguishing which portion of the silencing is due to absorbing shock in the elastomer and which is due to insulating the noise producing vibrations from the frame of the loom. The overall effect is to reduce noise, and it is of no interest whether this is effected primarily by shock absorption or by insulation of loom frame from the vibrations.

The present invention will be described primarily in connection with a Draper fly shuttle loom. Where there is some difference with other looms, this will be dealt with as the description proceeds.

The greatest single noise source is in the shuttle box at each end where the shuttle at the end of its trajectory is slowed down by the box, in which one of the side walls, both of which are lined with leather, is a pivoted wooden member urged by a spring. Final deceleration of the moving shuttle at the end of its trajectory results when it strikes the end of the picker stick. This may cause the other end of the shuttle to be forced down, contacting the lay end plate. Most of the noise is produced by the slowing down of the shuttle in the box rather than its eventual contacting in a depression in the end of the picker stick, and the noise is reduced by lining the sides of the back box plate with elastomer, such as polyurethane, and also the top of the lay end plate. All of these surfaces are struck by the shuttle, which may not always enter the box absolutely straight, and the resulting vibrations were transmitted to other portions of the loom and radiated as sound. The various elastomer linings referred to above reduce additional impact noise and, what is perhaps more important, reduce the transfer of vibration to other parts of the loom which can act as sound radiators. Before lining the lay end plate and the metal back box plate, they are preferably reduced in thickness by grinding or machining so that the elastomer layer, which is preferably cast from thermosetting polyurethane, restores the plate to its original thickness. Of course if a loom is built from scratch embodying the present invention, the same reduced thickness of metal should be present.

Each picker stick is connected to a pick arm on the pick shaft, which will be described below. The connection at the bottom, which throws the picker stick forward, propelling the shuttle, connects to the lower part of the picker stick, which, as is conventional, is pivoted, the connection being by means of a lug strap. This lug strap is clamped by a power block on the picker stick, which is tightened by a U-bolt. One of the changed members is to provide a molded polyurethane power block. This, however, is not a simple molding substituting the elastomer for metal as when this is tried the tightening of the U-bolt tends to cause the bottom of the power block to protrude and further tightening of the U-bolt simply makes this worse. The new power block is provided with a molded ridge or projection at its top only above the groove where the U-bolt passes, so that this forces the top of the power block away from the surface of the picker stick, and when the U-bolt is tightened, the power block finally clamps tightly against the picker stick and there is a marked reduction in noise.

Another source of noise is sideways vibration or rattling of the picker sticks. They move in guides, as is conventional, and there must be some play, otherwise the sticks can bind, for of course each stick is made of wood and can change its dimensions when the wood absorbs water. Another one of the elements of the invention, therefore, is the provision of elastomer linings on the sides of the picker stick which is, of course, reduced by the width of the lining. This lining performs two functions: First, it reduces the vibrational shock of the picker stick in its guide, and second, it isolates what residual noise there is from the loom itself, which reduces sound radiation.

At the top of each picker stick there has to be some restrainer, otherwise when the picker stick is thrown back by its conventional spring connection, it can move too far. In the Draper loom this is in the form of two leather straps which slap and cause considerable noise. In the present invention foamed elastomer is cemented onto one of the straps and prevents noise.

Another source of noise in fly shuttle looms results from the pick shaft on each side. This shaft, which is provided with an arm carrying the pick ball, which is a cam follower, and another arm moving the picker stick through lug strap connections, as has been described above, produces noise at three points. The metal ball itself is, of course, noisy due to the impact of the pick toe against the pick ball. There has to be a little play in the linkage and the cam wheel.

One of the elements of the present invention is a molded polyurethane or other elastomer replacing the metal ball. It is not a simple replacement of one material for another. When molded polyurethane was first used, it proved useless because in a very short time it was worn out. Only after extensive experiment was it found that the ball deteriorated because most polyurethane and other plastics swell or take a set on impact. This causes the ball to expand, bind, and rapidly wear out. Only an elastomer which does not significantly take a permanent set on impact could be made to work. One such non-swelling polyurethane is sold under the name of "Celanese 246."

The ends of the pick shaft on each side of the loom are journaled in plain metal journals called pick shaft boxes which are bolted to the loom frame. These are points where a great deal of noise is transmitted to the frame of the loom, and at first it was attempted to mold the metal tube into an elastomer block, one tube forming a bearing for the pick shaft and the others for the bolts, to bolt to the frame of the machine. When this was attempted with the rear box, there was sufficient shear stress so that the bearing tube for the pick shaft come out of alignment and, of course, bound. After extensive experiment it was found that welding a T-shaped piece of metal onto the bearing tube before the tube is molded as an insert into the elastomer block forming the box solved the problem. The tube does not bind and the boxes prevent or reduce transmission of vibrations to the loom frame. The rear box is different in design and shape from the original metal box.

Since the present invention permits reduction of noise from 10 to 15 decibels in a Draper loom, this is the preferred embodiment, although it is an advantage of the present invention that it can be used in other looms also, with the exception of the foam cushion for the restraining mechanism of the top of the picker sticks, which is only needed where check straps are used. However, the noise decrease may not be quite as great with some other looms as compared to the Draper loom, and therefore the modified Draper loom may be considered as the preferred embodiment of the present invention and will be described in more detail below in another section of the specification.

In the usual fly shuttle loom the picks shafts on each side are made of steel, which is needed because the rigid attachment of the boxes holding the bearing sleeves require fairly strong shafts. When the molded elastomer bearing boxes of the present invention are used, a much lighter shaft can be used, for example an aluminum shaft. A lighter shaft produces less vibration that has to be stopped; in other words there is less energy to dissipate. This is a further advantage as the lighter shaft not only saves weight but reduces vibration and shock loading somewhat, which even in the elastomer boxes is not reduced to zero. Therefore, where the maximum of noise reduction is desired, aluminum pick shafts may be used, but the invention is not limited thereto as the heavier steel shafts work perfectly with elastomer boxes but, of course, only with the special construction of the rear box, to reduce the noise of fly shuttle looms without requiring extensive redesigning of the loom.

It is obvious that the present invention could be used only in part. Thus, for example, only the greatest noise producers could employ the modifications of the present invention. Such a partial use of the present invention is not excluded. However, since even with all of the new elements of the present invention the reduction in noise just about meets the most severe legal standards, ordinarily all of the improvement of the present inventiton will be used, of course without using a foamed elastomer pad between check straps in looms which do not have this type of restrainer. The cost of the molded or cast elastomer elements is small once the expensive development of their design has been amortized, in fact negligible compared to the reduction in compensation claims when workers' hearing is impaired or where there are drastic state laws which do not permit the looms to be used. The advantages of the present invention are achieved without any offsetting disadvantages. Thus, for example, wear is not increased.

The invention will be described in greater detail in conjunction with polyurethane as the elastomer and a special kind of polyurethane which does not swell under impact in the case of the pick ball. These are not the only elastomers which can be used. For example, a copolymer of a glycol ether therphthalate and a diol terephthalate, sold under the trade name "Hytrel," is suitable for the boxes even though it cannot be used for the pick balls themselves as it is not sufficiently free from swelling under impact. In the case of all but the pick balls, the present invention can use any one of a number of well known elastomers of the thermosetting type for linings cast onto elements or thermoplastic type for molded boxes. In other words, the present invention does not distinguish from the prior art by the use of any particular peculiar elastomer. Even in the case of the pick balls, while the type of elastomer is more restricted, there are still a number of elastomers which show adequate lack of swelling under impact.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings show, often in semi-diagrammatic form, only those portions of a typical Draper fly shuttle loom where the changed members of the present invention are used. To show the whole loom would only unnecessarily confuse the drawings and in fact would not permit one to see some of the elements. Except for the new members themselves, the design, drive, and other features of the fly shuttle loom are not changed.

FIG. 1 is a perspective of a right hand shuttle box on a Draper fly shuttle loom;

FIG. 2 is a perspective of a link type parallel assembly with lug strap and power block installed on picker stick;

FIG. 3 is a perspective of the upper end of a left hand picker stick showing double strap restrainers;

FIG. 4 is a cut-away perspective showing elastomer damping applied to the box bottom plate;

FIG. 5 is a detail of an elastomer power block clamped on the left hand picker stick of FIG. 2;

FIG. 6 is a perspective of a front bearing block for the pick shaft;

FIG. 7 is a similar view for a rear bearing block;

FIG. 8 is a perspective of a molded pick ball;

FIG. 9 is a semi-diagrammatic showing of a right hand pick shaft with portions of the loom frame omitted for clarity, and

FIG. 10 is an enlarged detail of the back box plate in FIG. 1 showing the elastomer lining on both vertical and horizontal surfaces.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1, 2, 4, 8 and 9 show portions of the loom frame, only such portions being illustrated as are necessary to locate the elements of the present invention. For simplicity all of the portions of the loom frame shown in the figures are given the reference numeral (37) even though the figures do not all show the same part of a frame.

FIG. 1 shows the end of the lay (1), a hand rail (2), a back box plate (3) having a horizontal surface (39) with an elastomer lining (40), best seen in FIG. 10, a box bottom plate (4), which is shown in more detail in FIG. 4, a lining of cast elastomer (5), and the two leather-lined block plates (6), which is the leather-lined stationary plate, and (7), the plate pivoted on the frame at (8). As is conventional, this plate is urged inwardly by a spring arm, (not shown). The picker stick is shown at (9) with the picker (10). A check strap (11) is shown but can be seen in more detail in FIG. 3. The picker stick moves in a slot, which, of course, has dimensions considerably wider than the width of the stick itself. In FIG. 3 the picker stick is shown in more detail with cast elastomer pads (38). FIG. 3 is for a left hand picker stick, but of course the same construction is on the right hand picker stick, though it cannot be seen.

In FIG. 1 the vertical surface of the back box plate (3) is shown unlined in order not to confuse the drawing. A lining (41) is applied to the vertical surface of the plate as well as the elastomer lining (40) on the horizontal surface. FIG. 10 also shows the inclination of the horizontal surface more clearly.

When a shuttle enters the box shown in FIG. 1, it is only rarely perfectly straight, and as it moves toward the picker stick (9), the back of the shuttle usually strikes the vertical surface of (3). The shuttle then strikes the leather lining (7) forcing the binder to pivot outward and when the shuttle strikes the picker stick the back end also drops and strikes the plate (1). These are the principal sources of noise in the box. The back of the shuttle can also strike a plate (39), which can be seen in FIG. 1 and which is provided with a removable lining (40).

FIG. 4 shows the bottom plate of the box, which has been machined off and lined on the top with a cast lining of elastomer (5). There is not a great deal of impact on the plate, and the elastomer primarily insulates vibration from the plate, which is bolted direct to the lay and permits the latter to radiate sound.

FIG. 2 shows the left hand pick shaft of the loom, which is pivoted at its bottom and driven by an arm (36) on the pick shaft, which will be described below, through lug straps (13). FIG. 2 does not show the arm itself but this can be clearly seen in FIG. 9, which shows the right hand pick shaft. Molded elastomer power blocks (14) are clamped to the picker stick with U-bolts (15). It will be noted in FIG. 5 that the face of the power block contacting the picker stick above the U-bolt has molded on it a projection (16) at the top only of the block (14) which takes up the compression of the elastomer when the U-bolt is tightened that would otherwise cause the bottom of the power block to swing out from the picker stick. This part of the member is quite different in its design from the metal power block formerly used, which had a smooth face but which did not kick out at the bottom from the picker stick because of its rigidity. At first it was thought that the molded polyurethane would behave as the metal did, but it was only after extensive trial that it was found that the projection (16) was needed. The check straps (11), which are double and can be seen in FIG. 3, have a cushion of foamed polyurethane (17) between the two of them to reduce the slap when the picker stick is swung out to the position where it strikes the restrainer straps. The outer strap is partly broken away so that the cushion can be seen cemented to one of the straps. As can be seen from FIG. 3, the elastomer (17) is an open cell, foamed elastomer. This is the only element using a cellular elastomer. The other figures show elastomers, both cast and molded, which are non-cellular.

In FIG. 8 the pick ball is molded of special elastomer, shown at (27), which does not swell or take a permanent set on impact. FIG. 9 shows a right hand pick shaft (41). This shaft is provided with an arm carrying the pick ball (27), which is shown in more detail in FIG. 8. The ball bears on a cam rim (30) which is fastened to a cam shaft (31) and driven from a cam shaft gear (32), power for which is obtained from the loom drive. This connection is not shown as this portion of the loom is not changed by the present invention and is conventional. The two ends of the pick shaft (41) are numbered (34) for the rear end and (35) for the front end. These are shown in FIG. 9 in phantom as the portion of the frame is in front of them. The front end (35) of the pick shaft is journaled in a molded elastomer block with the journal sleeve (28), which can be seen in more detail in FIG. 6. This figure also shows metal tubes (29) for the attaching bolts (33), the ends of which can be seen in FIG. 9. A rear block, which is shown in FIG. 7, also shows a phantom a T-shaped member (18) which is welded onto the journal sleeve and prevents misalignment and hence binding, as has been described above. As the journal sleeves and metal tubes (29) for attaching bolts perform the same function as in FIG. 6, they are given the same numbers, it being noted, however, that the journal sleeve in FIG. 7 is somewhat different because of the T-shaped member (18).

While the pick ball itself has to be formed of special impact resistant elastomer (27), the molded bearing block may be of any suitable elastomer, such as the polyurethane described above for the pick ball, Hytrel, or any other suitable elastomer. The elastomer blocks insulate vibration from the side of the loom, which would otherwise be transmitted by the bolts bolting the usual metal block to the frame. While the rear block of FIG. 7 is of special design with a welded-on projection (18), the shape of the actual molding is the same as that of the metal bearing block in a conventional loom which it replaces.

The oscillating pick shafts (41), the right hand one of which is illustrated in FIG. 9, connect to the right and left hand picker sticks respectively through straps (13) from the pick arms (36). In FIG. 9 only a portion of the strap is shown as this figure does not illustrate the right hand picker stick in order not to confuse the drawings. In FIG. 2, for the left hand picker stick, the connection of the strap (13) to the block (14) is shown in more detail. A similar connection with the same kind of block and U-bolt is provided for the right hand picker stick. A portion of this picker stick is shown in FIG. 3 and carries the same number, (9), as the left hand picker stick in FIG. 2. It can readily be seen from FIG. 9 that there is considerable impact between the cam ring (30) and the pick ball (27), which is why the latter must be made of the special kind of elastomer which does not swell or take a set on impact.

Claims

I claim:

1. In a fly shuttle loom including loom drive, lay and shuttle boxes, cams, pick ball and pick shaft, and connections to picker sticks which force the shuttle to fly from side to side, the shuttle boxes on each end of the lay comprising leather lined side plates, one of them pivoted onto the lay and the other fixed, and a box back plate above the shuttle trajectory and a lay end plate at the bottom of the box in which plate the picker stick head moves, the improvement which comprises,

a. a composite lay end plate positioned to come into contact with and guide the shuttle, the metal portion of said plate having thickness less than the full thickness and cast non-cellular thermosetting elastomer lining thereon to bring up to normal thickness, and

b. an elastomer lining on the side wall of the back box plate, whereby the elastomer linings reduce noise produced in the shuttle boxes and also redue transmission of vibrations to the loom structure.

2. A fly shuttle loom according to claim 1 in which the sides of the picker stick moving in the lay end plate are provided with inserted elastomer pads whereby sideways rattling of the picker stick in the lay end plate and vibration and noise transmission to the lay are reduced.

3. A fly shuttle loom according to claim 1 in which each picker stick is driven from the pick shaft through lug straps, which straps are clamped to the picker stick by a molded elastomer power block with a groove for a clamping U-bolt and a single projection on the surface of the elastomer power block above the U-bolt sufficient to prevent the bottom of the power block from swinging out from the picker stick when the U-bolt is tightened, whereby noise production and radiation are further reduced.

4. A fly shuttle loom according to claim 2 in which each picker stick is driven from the pick shaft through lug straps, which straps are clamped to the picker stick by a molded elastomer power block with a groove for a clamping U-bolt and a single projection on the surface of the elastomer power block above the U-bolt sufficient to prevent the bottom of the power block from swinging out from the picker stick when the U-bolt is tightened, whereby noise production and radiation are further reduced.

5. A fly shuttle loom according to claim 3 in which the pick shaft is journaled in metal sleeves in the molded elastomer boxes, the rear box having a T-shaped part welded to the bearing tube and molded into the elastomer block.

6. A fly shuttle loom according to claim 4 in which the pick shaft is journaled in metal sleeves in the molded elastomer boxes, the rear box having a T-shaped part welded to the bearing tube and molded into the elastomer block, whereby noise from the pick shaft and its boxes is reduced.

7. A fly shuttle loom according to claim 5 in which the pick ball is a unitary block of molded elastomer which does not take a permanent set under impact, whereby noise from the pick shaft and its boxes is reduced.

8. A fly shuttle loom according to claim 6 in which the pick ball is a unitary block of molded elastomer which does not take a permanent set under impact, whereby noise from the pick ball is also reduced.

9. A fly shuttle loom according to claim 1 in which each picker stick is restrained at its top from swinging too far out by double check straps with a foam elastomer pad cemented to one of the straps and bearing on the other.

10. A fly shuttle loom accoridng to claim 2 in which each picker stick is restrained at its top from swinging too far out by double check straps with a foam elastomer pad cemented to one of the straps and bearing on the other.