U.S. patent number 3,868,975 [Application Number 05/354,950] was granted by the patent office on 1975-03-04 for fly shuttle loom and parts thereof.
This patent grant is currently assigned to J. P. Stevens Co., Inc.. Invention is credited to Allen L. Cudworth, Joseph E. Stahl.
United States Patent |
3,868,975 |
Stahl , et al. |
March 4, 1975 |
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.
Inventors: |
Stahl; Joseph E. (Easthampton,
MA), Cudworth; Allen L. (Needham, MA) |
Assignee: |
J. P. Stevens Co., Inc. (New
York, NY)
|
Family
ID: |
23395582 |
Appl.
No.: |
05/354,950 |
Filed: |
April 27, 1973 |
Current U.S.
Class: |
139/1R; 139/151;
139/166; 139/147; 139/154; 139/183 |
Current CPC
Class: |
D03D
49/027 (20130101); D03D 49/60 (20130101); D03D
49/36 (20130101) |
Current International
Class: |
D03D
49/36 (20060101); D03D 49/00 (20060101); D03D
49/60 (20060101); D03d 049/00 () |
Field of
Search: |
;139/1R,183,184,151-154,142,147,157 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1,352,422 |
|
Jan 1964 |
|
FR |
|
518,195 |
|
Mar 1953 |
|
BE |
|
688,571 |
|
Jan 1940 |
|
DD |
|
254,213 |
|
Dec 1948 |
|
CH |
|
Other References
Millmaster Power Strap For Use on Picanol Looms, The Gates Rubber
Co., Denver, Colorado, Product No. 1211-10..
|
Primary Examiner: Kee Chi; James
Attorney, Agent or Firm: Norton; Robert Ames Leitner;
Saul
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.
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.
* * * * *