US3643880A

US3643880A - Material cutting machine and sound-absorbing hood therefor

Info

Publication number: US3643880A
Application number: US63066A
Authority: US
Inventors: Russell I Peterson Jr
Original assignee: Cumberland Engineering Corp
Current assignee: Cumberland Engineering Corp
Priority date: 1970-08-12
Filing date: 1970-08-12
Publication date: 1972-02-22
Anticipated expiration: 1989-02-22

Abstract

The invention is a machine for comminuting material in which a rotary cutting mechanism is used. A hood is mounted on the machine adjacent the inlet passage thereto, the function of the hood being to minimize the noise caused by the machine when it cuts material. Throughout the machine, additional sound-absorbing means are used at strategic locations to eliminate or minimize the passage of sound from the inside of the total enclosure of the machine to the outside thereof.

Description

Feb. 22, 1972 United States Patent Peterson, Jr.

.....24l/285 B Smith.................................24l/285 R 1541 MATERIAL CUTTING MACHINE AND 3,419,223 12/1968 Morin...............

SOUND-ABSORBING HOOD THEREFOR 3,589,624 /1971 [72] Inventor: Russell 1. Peterson, Jr., Seekonk, Mass.

Assignee: Cumberland Engineering Company Inc., Primary Examiner P Pawtucket, R1, Attorney-Kenway, .lenney & Hildreth Aug. 12, 19 10 [57] ABSTRACT The invention is a machine for comminuting material in which [22] Filed:

[21] Appl. No.: 63,066

a rotary cutting mechanism is used. A hood is mounted on the the function of the ..241/100, 241/286 B, 241/301 machine adjacent the inlet passage thereto,

. ...B02c 23/00, B02 18/00 hood being to minimize the noise caused by the machine when .241/100, 101 R, 185 R, 186 R, it cuts material. Throughout the machine, additional sound- 286 A, 286 B, 301 absorbing means are used at strategic locations to eliminate or [52] US. CL... [51] Int. [58] Field of Search..............

minimize the passage of sound from the inside of the total enclosure of the machine to the outside thereof.

[56] References Cited UNITED STATES PATENTS 12 Claims, 4 Drawing Figures Hess et PAIENTEUFEB 22 I972 SHEET 1 OF 2 FIG 2 FIG. 3

INVENTOR RUSSELL I. PETERSON,JR.

ATTORNEYS PAIENTEDFEB2ZIQTZ 3.643.880 SHEET 2 OF 2 FIG 4 INVENTOR RUSSELL l. PETERSONJR ATTORNEYS MATERIAL CUTTING MACHINE AND SOUND- ABSORBING HOOD THEREFOR BACKGROUND OF THE INVENTION The invention has particularly to do with machines called granulators that are used to chop up or comminute plastic materials. Such machines create a great deal of noise. The reason for the noise is that many of the plastics used today are very tough, and when they are comminuted, the cutting action is very noisy due to the kind of knives used. In addition, due to the rotary action of the cutting means, hard particles of plastic are thrown with some force against the steel walls of the machine with resulting noise.

Attempts have been made to fashion sound-absorbing hoods for such machines, and to assemble a combination of the sound-absorbing hood and the machine which would be convenient to use and which would permit ready access to the working parts of the machine without having to lift the hood therefrom. Such hoods generally are made of extremely thick metal for the purpose of avoiding vibration of the material when struck by the particles of plastic inside the machine, metal being used to withstand the abrasion of the thrown particles. Such constructions have serious drawbacks in that when such a hood is made of very thick material it requires a crane or hoist to remove it from the machine in order to have access to the interior working parts thereof. As a result, while such hoods have been made, they are not considered to be very practical or economical.

In addition, it has been known that material such as clay and epoxy coatings on metal, soft metals such as lead and aluminum, and the foamed plastics all have an ability to absorb or attenuate sound impinging thereon to some degree. Such materials have been used, but it has been found that when so used in what would be considered the normal manner, the noise level of the machine was reduced but not sufficiently to have much significance.

It has been said that 90 percent of noise created in the interior of a noisy machine will exit from an opening in the machine amounting to only percent of a covering for the machine. This factor creates the problem of how to feed scrap material into machines which have noise suppression hoods associated therewith, because feeding the materials into the machine must be done through an opening, with the result that interior noise will escape through the feed opening. Using screens to mask the feed opening will help, but is not enough.

Therefore, it is the general purpose of this invention to provide a machine and enclosure therefor having the following important objectives and characteristics:

One object of the invention is to provide an enclosure for a cutting machine, in which the enclosure is double-walled, and so made that noise is significantly attenuated and absorbed before it can reach the outside of the machine and the enclosure.

Another object of the invention is to provide a combined enclosure and feed hopper for a cutting machine which can be easily attached to a machine so as to be movable with respect thereto, the combined enclosure-hopper being so mounted on the machine that a single man of normal strength can move the enclosure and feed hopper with respect to the machine so that ready access to the interior of the machine can be had for maintenance purposes.

Still another object of the invention is to provide apparatus of the aforementioned kinds, in which the materials used to absorb and attenuate the sound of the machine can be readily attainable on the open market at cost which is not prohibitively expensive.

Another object of the invention is the provision of a combined enclosure and feed hopper of any of the abovedescribed kinds, as well as a material receiving hopper therefor, can be readily fabricated,-in accordance with the instructions of this disclosure, in any average machine shop which has equipment suitable for fabricating articles out of sheet and plate metals.

Other objects and advantages will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, arrangements of parts, and manipulation of the apparatus all of which will be exemplified in the structures hereinafter set forth, and the scope of the application of which will be indicated in the appended claims.

In the accompanying drawings, in which one of the various possible embodiments of the invention is illustrated:

FIG. I is a perspective view of the combined enclosure and hopper of this invention attached to the base of a material cutting machine. (In this drawing, the motor that drives the machine has been deleted for purposes of clarity.)

FIG. 2 is a vertical cross-sectional view of the machine, with certain parts cut away in order to illustrate the general interior construction of both the machine and the combined enclosure and feed hopper thereof. In this view, a second position of the combined enclosure-feed hopper is shown.

FIG. 3 is a vertical elevation of a portion of the above embodiment of this invention, and is given to show a motor in place, with certain sound-absorbing and attenuating means being provided in connection with the drive pulley mounted on the shaft of the motor.

FIG. 4 is a sectional plan view of the combined enclosure and feed hopper ofthis invention, taken in the direction of sight lines 4-4 on FIG. 2, the view being given in orderto illustrate the construction of the walls of the outer enclosure and the walls of the inner feed hopper.

Similar reference characters indicate corresponding parts throughout several views of the drawing. In the drawings, dimensions of certain of the parts as shown may have been modified and/orexaggerated for the purposes of clarity of illustration and understanding the invention.

Referring now to FIGS. 1 and 2, there is illustrated one embodiment of this invention comprising a material cutting machine indicated generally by numeral 2, the machine having a base 4 within which is mounted a rotary cutting mechanism indicated generally by numeral 6, and an inlet 8 and outlet 10. Such a machine is one which is built, for example, by Cumberland Engineering Company Inc. of Pawtucket R.I., and is illustrated in Bulletin No. 700 of that company, for example, Model 2 Granulator using a 10 motor at 1,800 rpm. It will be noted that the inlet 8 is at the upper side of the granulator and the exit 10 is at the lower, so that material is fed into the granulator from the top downwardly. Mounted on the base 4 is an electrical motor 12 (see FIG. 2) mounting being done by customary bolts on the mounting plate 14 which is also conventional. The motor is provided with a shaft 16, as is usual, and at the end of the shaft 16 is mounted the multiple groove V-pulley 18 which is used to drive the cutting mechanism 6 by means of a similar multiple groove V-pulley 20 mounted at the end of the rotary cutter of the machine.

Mounted on top of the base 4 is the combined enclosurefeed hopper structure of this invention, indicated generally by numeral 26. The structure 26 is hinged on the base 4, for example, by the pivots 28, one on each side of the 'base and, respectively, the sidewalls of the enclosure, suitable lugs being provided on the sidewalls of the base and the sidewalls of the enclosure for the purpose. Since the construction of the pivots is conventional, no further description will be given. Of course, if desired, other means of hinging or pivoting the enclosure 26 on the base can be provided.

The purpose of hinging the base is so that, as shown by the dot-dash lines in FIG. 2, the enclosure 26 may be swung to the position 30 as shown in FIG. 2. It will be observed that the shape of the combined enclosure and hopper is such that the entire structure is well balanced on the pivots or hinge 28. Therefore, even though the structure may beheavy, it can be easily moved from the full line position shown in FIG. 2, to the dotted line position by a man of ordinary strength. However, in the full line position shown in FIG. 2, the enclosure 26 is seated firmly on the slanting upper table 32 of the base.

As illustrated in FIGS. 2 and 4, the structure 26 is constructed as follows: Speaking first of the outer enclosure, it has in general an inverted L-shape, with the horizontally extending arm 34 and an approximately vertical leg portion 36. The enclosure has

sidewalls

38 and 40, backwall 42, and front wall 44. Each of the walls has a plural-layered construction, in which the outermost first layer is a sound attenuation material, and the inner layers are sound-absorption and sound attenuation material. As an example of the respective materials, the outermost layer of wall 38, for example, is a sheet of aluminum 46, this being selected because of its inert characteristics so far as vibrations are concerned. Other materials could be used, for example, such as brass or copper, but it is felt that the aluminum provides the sound attenuation required and yet at the same time is light and provides sufficient strength and rigidity to maintain the shape of the outer enclosure. The outer layers of all of the walls of the enclosure are similarly made of sheet aluminum. Next in order, inwardly, is a layer of foamed absorbing material 48 in each wall, next a layer of metallic lead 50, and finally an innermost layer of foamed absorbing material 52. The lead layer 50 acts as a damping and sound attenuating layer, and the two foamed

layers

48 and 52 constitute sound-absorbing layers. It is preferred that the foamed

layers

48 and 52 be of polyurethane foam, but other foamed synthetic artificial plastic resins may be used if desired. The

layers

48, 50 and 52 are preferably fastened together by suitable adhesive and this combination is then preferably fastened to the layer 46 by a suitable adhesive. A suitable adhesive may be, for example, a contact cement such as an epoxy resin, any number of which are commonly available on the market.

As an example of the thicknesses of the relative layers, the layer of aluminum 46 may be approximately 0.092 inches thick; the layer of foam material 48 may be approximately one-fourth inch thick; the layer of lead may be approximately one-thirtysecond inch thick; and the innermost layer of polyurethane foamed material may be approximately 1 inch thick. (Material such as that comprising the three

layers

48, 50 and 52 may be purchased from the Sound Coat Co., l5 Madison Avenue, New York, NY. 10022, if desired.)

Walls

42, 40 and 44 are the same as that described for wall 38.

Front wall 44 has an opening 56 provided therein adapted to align with the front end opening 58 of the interior hopper indicated generally by numeral 60. A rectangularly shaped sleeve 62 is inserted within the opening 56 and also within the opening 58, the sleeve having an exterior flange 64 by means of which it is fastened to the aluminum face of the front wall 44 in conventional manner by means of the screws 66. The interior end of the sleeve serves to hold the end of the hopper 60 in position with respect to the opening 56in the front wall 44.

Like the enclosure 26, the hopper 60 is also L-shaped, and comprises a rectangular tubular structure having the sidewalls 70 and 72, backwall 74, bottom 76, top 77 and vertical front wall 78. As a result of this construction, the hopper resembles to a great extent the shape of the outside enclosure 26, except that it is smaller. The outer surfaces of the hopper are coated with a sound attenuating material 61 which is a clay-epoxy resin mixture purchasable, if desired, from the Sound Coat C0. and sold as GP I material; or if desired, the layer 61 may be vermiculite.

The entire hopper thus fits approximately centrally within the enclosure 26, and is held spaced therefrom by suitable brackets 80 which extend from the enclosure 26 to the hopper. The exact location of these brackets is not critical, and their function is simply to space the hopper from the enclosure.

Attached to the lower or inner end of the hopper 60 are the reinforcing plates 82 which surround the hopper on all four sides. These reinforcements are made of heavy sheet metal, and are attached by welding or riveting to the hopper walls. The purpose of having the reinforcements is to strengthen the hopper and stiffen it, particularly since it is against the bottom or inner end of the hopper that particles may be thrown by the rotatingcutting machine with considerable force. The perimeter of the hopper at the bottom is so shaped that when the enclosure 26 is in the position (upright) as shown in FIG. 2, the

perimeter rests adjacent the plane defining the inlet passage 8 of the granulator 6.

From the construction, it is clear that material is fed into the machine via hopper 60 and then falls by gravity into the granulator. In view of the fact that a very large amount of sound would exit from the interior of the machine through the upper horizontal throat of the hopper 60, unless this is blocked off, it is necessary to close this throat but still allow material to be fed into the granulator through this passageway. Therefore, means are provided to block off the noise. This is done conveniently by a plurality of flexible sheet material curtains 86, each curtain comprising two flexible

elastomeric sheets

88 and 90, such as Neoprene, which are fastened to the top of the hopper by conventional means such as the straps 92. The curtains hang downwardly until they almost touch the bottom floor 76 of the hopper. The members of each pair hang closely together. Thus, since the curtains are flexible and freely swinging, material may be introduced into the upper horizontal leg of the hopper and once the material is introduced, the curtains then again hang down and block any noise trying to emerge from the hopper. One or more of the curtains may be, if desired, impregnated with lead particles.

The members of the pair of curtains 86 at the entrance of the hopper may be fastened thereto by the framework 92 which is suitably held against the sleeve 62 by the screws 66. The attachment of the curtains to the hopper is conventional, no further description will be given herein.

At the lower end of the backwall 36 of the enclosure there is provided a slot 94 open at its bottom end. Mounted on the base 4 is a pulleyand belt-shrouding member 96 whose inner end 98 extends within the enclosure. The shroud 96 is detachably fastened to base 4. A soft flexible gasket 100 surrounds the edge of the slot, so that when the enclosure is in the position shown in FIG. 1, there is a basically soundtight seal between the enclosure and the shroud 96. A hole 102 is provided in the wall of the shroud and is adapted to receive therethrough the shaft 16 of the motor.

One function of shroud 96 is to enclose V-pulley l8 and the transmission belts 22, in order to protect any user of the machine from becoming entangled with the drive means. A second purpose of the shroud is to provide a sound barrier, and it may, if desired, have a coating on the inside thereof equivalent to the coating 61 which is on the outside of the hopper walls. The effect of such a coating will be to dampen any vibrations of the shroud 96, but the problem of sound emerging from the hole 102 still remains/This matter is taken care of in this invention by including snugly between the end 104 of the motor frame and the wall of the enclosure (see FIG. 3), a resilient pad 106 of cushioning material which blocks off the emergence of any sound from the hole 102. The fit of pad 106 around shaft 16 is a running fit, preferably.

The material of the sound-absorbing cushion 106 preferably is a foamed polyurethane synthetic plastic resin, such as is used for the layer 52. Or, if desired, the cushion 106 can be a composite layer such as the

total layer

48,50,52 as shown in FIG. 4, That is, the cushion 106 can be a layer of polyurethane foam approximately one-fourth inch thick, then a layer of lead approximately one-thirtysecond inch thick, and finally another layer of polyurethane foam approximately 1 inch thick.

By the construction thus described, the enclosure 26 may be swung about the pivot points 28 to the position shown by the dot-dash lines 30 in FIG. 2, and as it so swings the open end of the slot 94 will permit the bottom end of the enclosure 26 to escape from the belt shroud 96.

In the position shown in FIG. 2 in full lines, that is, the upright position, the enclosure 26 is securely anchored to the base 10 by means of Iatchbolts 106 which extend through the eyes 108 fastened to wall 42, nuts being provided for conventional anchoring purposes.

Referring to FIG. 2, there is shown in dotted lines a bin 110 of conventional structure, which is attached to the bed of the cutting machine adjacent the exit 10 thereof. The bin is preferably a four-sided structure having conventional walls, and at the open end of the bin there is provided a flange 112 which surrounds the periphery of this open end. The flange, when the bin is positioned, seats itself firmly against the underside of the bed 32, and the bin is clamped into position by means of the fixed bracket 114 and the movable dog [16 which may be loosened andturned in order to remove the bin. If desired, but not shown, suitable gasketing material may be mounted between the flange 112 of the bin and the base of the bed 32.

in view of the above, it will be seen that the several objects are achieved, and other advantageous results attained.

it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense, and it is also intended that the appended claims shall cover all such equivalent variations as come within the true spirit and scope of the invention.

Having described the invention, what is claimed is:

l. A sound-absorbing combined hopper and enclosure structure for a machine for cutting materials, the machine having a base, cutting means mounted on the base, a motor for driving the cutting means, and inlet and exit passage means to and from the cutting means, comprising:

an elongated tubular structure having outside and inside composite walls, the walls being spaced apart to provide an airspace therebetween, the-outer walls forming the enclosure and the inside walls forming the hopper, and including means holding the walls in their spaced relation whereby the combined outside and inside walls are adapted to move together;

the outer composite wall being a plural-layered structure comprising an outermost first layer of sound attenuation material and inner layers of sound-absorption material and sound attenuation material; the inner composite wall comprising at least two layers of material, a first innermost layer being of a wear-resistant metal and a second outer layer being a sound damping layer, the two layers being attached to each other; and

said tubular structure being movably hinged to said base with the inner end of said hopper being located adjacent the mouth of said inlet passage, the structure being movable on said hinge to swing away from said inlet passageway and said cutter, thereby to permit access to the latter.

2. The structure of claim 1 in which the layers of the outer composite wall comprise, in the order named from outside to inside, a layer of aluminum, a layer of artificial foamed plastic resin, a layer of lead, and a layer of artificial foamed plastic resin.

3. The structure of claim 2 in which the artificial foamed plastic resin is polyurethane.

4. The structure of claim 1 in which the layers of the inner composite wall comprise, in the order named from outside to inside, a layer of vermiculite, and a layer of steel, the latter being the innermost layer of the hopper.

S. The structure of claim 1 in which the combined enclosure and hopper structure is generally L-shaped and vertically oriented, one leg of the L-shape extending substantially horizontally, the other leg of the L-shape being connected to the base with the hopper adjacent said inlet passage and including a plurality of sound minimizing curtains in said horizontally extending leg attached to the top of the hopper and freely hanging downwardly toward the bottom of the horizontal section of the hopper, said curtains comprising flexible sheets of an elastomer.

6. The structure of claim 5 in which the layers of the outer composite wall comprise in the order named from outside to inside: a layer of aluminum, a layer of artificial foamed plastic resin, a layer of lead, and a layer of artificial foamed plastic resin; and the layers of the innermost composite wall comprise, in the order named from outside to inside, a layer of vermiculite and a layer of steel, and said curtains comprise a plurality of pairs of curtains, each pair comprising two of said sheets hanging closely adjacent each other.

7. A machine for cutting materials, comprising a base;

cutting means mounted on the base;

a motor for driving the cutting means;

inlet and exit passage means to and from the cutting means;

a sound-absorbing combined enclosure and hopper struc ture, said structure comprising:

an elongated tubular structure having outside and inside composite walls, the walls being spaced apart to provide an airspace therebetween, the outer walls forming the enclosure and the inside walls forming the hopper, and including means holding the walls in their spaced relation whereby the combined outside and inside walls are adapted to move together;

the outer composite wall being a plural-layered structure comprising an outermost first layer of sound attenuation material and inner layers of sound-absorption material and sound attenuation material; the inner composite wall comprising at least two layers of material, a first innermost layer being of a wear-resistant metal, and a second outer layer being a sound damping layer, the two layers being attached to each other; and

8. The machine of claim 7 including a bin removably fastened to said base adjacent said exit passage in position to receive material emerging therefrom, and sound-absorbing means forming a gasket between the edges of said bin and said base.

9. The machine of claim 7 in which said motor has a shaft and a pulley mounted thereon, said cutting means has a shaft and a pulley mounted thereon, and including a transmission belt connecting said pulleys, and also including a shroud for said belt and for said pulleys, said shaft passing through one wall of the shroud, and sound-absorbing material snugly fitted between the end of the frame of the motor-and the wall of said shroud where the shaft passes through the wall, thereby to prevent the egress of sound from the interior of said shroud to the outside thereof.

10. The machine of claim 7 in which the combined enclosure and hopper structure is generally L-shaped and vertically oriented, one leg of the structure extending generally horizontally and the other leg of the structure extending generally vertically and being connected to said base with the hopper adjacent said inlet passage, the machine including a plurality of sound minimizing curtains in said horizontally extending leg, the curtains being attached to the top of the hopper and freely hanging downwardly toward the bottom of the horizontal section of the hopper.

11. The machine of claim 10 in which at least one of said curtains comprising a flexible sheet of synthetic plastic impregnated with lead particles, and at least one other of said curtains comprising two flexible layers of sheet elastomeric material attached to the top of the hopper and hanging downwardly adjacent each other.

12. The structure of claim 7 in which the layers of the outer composite wall comprise in the order named from the outside to inside; a layer of aluminum, a layer of artificial foamed plastic resin, a layer of lead, and a layer of artificial foam plastic resin; and layers of the innermost composite wall comprise, in the order named from outside to inside, a layer of sound attenuating material and a layer of steel.

Claims

1. A sound-absorbing combined hopper and enclosure structure for a machine for cutting materials, the machine having a base, cutting means mounted on the base, a motor for driving the cutting means, and inlet and exit passage means to and from the cutting means, comprising: an elongated tubular structure haviNg outside and inside composite walls, the walls being spaced apart to provide an airspace therebetween, the outer walls forming the enclosure and the inside walls forming the hopper, and including means holding the walls in their spaced relation whereby the combined outside and inside walls are adapted to move together; the outer composite wall being a plural-layered structure comprising an outermost first layer of sound attenuation material and inner layers of sound-absorption material and sound attenuation material; the inner composite wall comprising at least two layers of material, a first innermost layer being of a wear-resistant metal and a second outer layer being a sound damping layer, the two layers being attached to each other; and said tubular structure being movably hinged to said base with the inner end of said hopper being located adjacent the mouth of said inlet passage, the structure being movable on said hinge to swing away from said inlet passageway and said cutter, thereby to permit access to the latter.

5. The structure of claim 1 in which the combined enclosure and hopper structure is generally L-shaped and vertically oriented, one leg of the L-shape extending substantially horizontally, the other leg of the L-shape being connected to the base with the hopper adjacent said inlet passage and including a plurality of sound minimizing curtains in said horizontally extending leg attached to the top of the hopper and freely hanging downwardly toward the bottom of the horizontal section of the hopper, said curtains comprising flexible sheets of an elastomer.

7. A machine for cutting materials, comprising a base; cutting means mounted on the base; a motor for driving the cutting means; inlet and exit passage means to and from the cutting means; a sound-absorbing combined enclosure and hopper structure, said structure comprising: an elongated tubular structure having outside and inside composite walls, the walls being spaced apart to provide an airspace therebetween, the outer walls forming the enclosure and the inside walls forming the hopper, and including means holding the walls in their spaced relation whereby the combined outside and inside walls are adapted to move together; the outer composite wall being a plural-layered structure comprising an outermost first layer of sound attenuation material and inner layers of sound-absorption material and sound attenuation material; the inner composite wall comprising at least two layers of material, a first innermost layer being of a wear-resistant metal, and a second outer layer being a sound damping layer, the two layers being attached to each other; and said tubular structure being movably hinged to said base with the inner end of said hopper being located adjacent the mouth of said inlet passage, the structure being movable on said hinge to swiNg away from said inlet passageway and said cutter, thereby to permit access to the latter.

9. The machine of claim 7 in which said motor has a shaft and a pulley mounted thereon, said cutting means has a shaft and a pulley mounted thereon, and including a transmission belt connecting said pulleys, and also including a shroud for said belt and for said pulleys, said shaft passing through one wall of the shroud, and sound-absorbing material snugly fitted between the end of the frame of the motor and the wall of said shroud where the shaft passes through the wall, thereby to prevent the egress of sound from the interior of said shroud to the outside thereof.