US3016091A

US3016091A - Vacuum control for pulp molding machines

Info

Publication number: US3016091A
Application number: US48886A
Authority: US
Inventors: Donald T Daniele
Original assignee: Diamond National Corp
Current assignee: Diamond National Corp
Priority date: 1960-08-11
Filing date: 1960-08-11
Publication date: 1962-01-09
Anticipated expiration: 1979-01-09

Description

Jan. 9, 1962 Filed Aug. 11, 1960 D. T. DANIELE 3,016,091

VACUUM CONTROL FOR PULP MOLDING MACHINES 5 Sheets-Sheet l #IT'. .93 I v N I a w l 2 9 9 .8 l m g E; :II I I" i 5 i ll i N n o i g I i I l '1 U i 1 l I i i 8 I l l g i 1 I '1 1| I I h "Tin INVENTOR Donald T. Daniele ATTORNEY D. T. DANIELE VACUUM CONTROL FOR PULP MOLDING MACHINES Jan. 9, 1962 I 3 Sheets-Sheet 2 Filed Aug. 11, 1960 INVENTOR Donald l1 Daniele ATTORNEY Illll 8 w 5 I? -I-= w x r1.5% .=iIlli==i 8 i .n t 7 BY KARI. LJTZoc K5 Jan. 9, 1962 I D. T. DANIELE 3,016,091

VACUUM CONTROL FOR PULP MOLDING MACHINES Filed Aug. 11, 1960 3 Sheets-Sheet s INVENTOR Dona Id 'IZ Daniele BY KARI. 'FZ ocKs ATTORNEY United States Patent 3,016,091 VACUUM CONTROL FOR PULP MOLDING MACHINES Donald T. Daniele, East Longmeadow, Mass, assignor to Diamond National Corporation, New York, N.Y., a

corporation of Delaware Filed Aug. 11, 1960, Ser. No. 48,886

9 Claims. (Cl. 162-391) This invention relates to vacuum controls for pulp molding machines, and more particularly to a valve for controlling the periodic application of a vacuum to suctiontype rotary pulp molding machines. This application is a continuationin-part of application Serial No. 801,884, filed March 25, 1959, by the same inventor, now abandoned.

In the manufacture of molded pulp articles by suctiontype rotary pulp molding machines, a vacuum is customarily applied periodically to a series of suction molds as they are advanced successively through a vat of pulp slurry, in which the pulp articles are formed by suction deposition onto the molds. Subsequently, the pulp articles are removed from the molds by a plurality of cooperating transfer dies, to which the vacuum is also periodically applied to hold the pulp articles thereon temporarily. These dies may transfer the articles to a conveyor leading through a drying oven to a stacking and storage area. In some types of molding machines the transfer dies are mounted on a hollow rotatable shaft for oscillatory movement through an arc of 180 back and forth between an article receiving position and an article discharge position, and the vacuum is applied intermittently to the dies through the hollow shaft on which they are mounted during such oscillation. For such purposes, various complicated controls and complex valve structures have been proposed heretofore to regulate the application of the vacuum thereto.

An object of the present invention is to provide new and improved vacuum controls for pulp molding machines.

Another object of the invention is to provide new and improved valves for controlling the periodic application of vacuum to suction-type rotary pulp molding machines.

Still another object of the invention is to provide new and improved controls for periodically applying pneumatic or other fluid motive power to rotating or oscillating article carrying elements of pulp molding machines.

Yet another object of the invention is to provide a new and improved valve for controlling the periodic application of vacuum to an oscillatable transfer die.

Other objects and the nature and advantages of the instant invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic side elevation view of one type of pulp molding machine in which controls embodying the present invention may be incorporated;

FIG. 2 is a fragmentary vertical section of a plurality of oscillatable transfer dies mounted on a hollow rotatable shaft which is connected to a vacuum control device embodying the present invention;

FIG. 3 is an enlarged vertical section of the control device shown in FIG. 2, depicted in one operating position;

FIG. 4 is a view corresponding to FIG. 3, but showing the control device in another operating position;

FIG. 5 is a transverse vertical section taken along the line 55 of FIG. 3; and

FIG. 6 is a vertical section taken along the line 66 of FIG. 3.

The pulp molding machine illustrated schematically in FIG. 1 is representative of one well known type of ma 3,016,091 Patented Jan. 9, 1962 chine used commercially for the production of relatively simple molded pulp articles, such as dishes, flower pots or other types of containers. This machine comprises a plurality of suction molds 10 mounted on hollow spokes 12 which project radially outwardly from an intermittently rotatable hollow shaft 14 adapted to advance the molds 10 in a circular path successively through a vat 16 containing dilute pulp slurry. Vacuum is applied internally to the molds 10 through the spokes 12 and the shaft 14 as the molds 10 advance through the pulp slurry in the vat 16 to form molded pulp articles by suction deposition onto the molds. As the molds 10 emerge from the pulp slurry and rise upwardly thereabove, the application of the vacuum is continued to drain excess moisture from the molded pulp articles thereon.

When the molds 10 reach the uppermost position in their circular path of travel, the vacuum is automatically shut off and an internal blast of compressed air may be applied to transfer the molded pulp articles to a traveling compression and transfer die 18 suspended directly above the molds 10. The die 18 is capable of both vertical and horizontal reciprocation, and it is movable along a horizontal track 20 to carry the molded pulp articles successively over to a position directly above an oscillatable transfer die 22, which is adapted to invert the molded pulp'articles and transfer them to a conveyor belt 24. The transfer die 22 is mounted on a hollow rotatable shaft 26 through which vacuum is applied intermittently to hold the pulp articles on the die 22. The vacuum is applied as the articles are received from the die 18 and as they are carried through an arc of 180 to an inverted position above the conveyor belt 24, and then the vacuum is automatically shut off to allow the articles to drop onto the conveyor belt 24.

FIG. 2 shows a plurality of transverse dies 30, corresponding to the die 22 of FIG. 1, mounted on a common horizontal hollow rotatable shaft 32 journaled in a vertical frame 34, of which only a fragment is shown. Suitable driving means 35 is provided for turning the rotatable shaft 32 alternately in opposite direction in steps of 180, thereby to oscillate the dies 30 in the same manner as has been described for the die 22 of FIG. 1. During this oscillatory motion a vacuum control embodying the present invention, indicated generally at 36, controls the periodic application of the vacuum to the dies 30.

The vacuum control device 36 comprises a valve head 38, which in the illustrated embodiment of the invention is annular in configuration, secured by bolts 40 to a base 42 mounted on a horizontal bracket 44 projecting" laterally from the frame 34. Thus, the valve head 38 is securely anchored against rotation with the rotatable shaft 32 on which the transfer dies 30 are mounted. The hollow shaft 32 is joined by a keyed union member 45 to a hollow shaft extension 46 which projects horizontally outwardly through the frame 34 and thence through a bearing 48 secured to said frame. The outer end of the hollow shaft extension 46 terminates in an integral, solid, reduced portion 50, which is journaled within a second bearing 52 mounted on the bracket 44 at its outer end. A ported flange 54 is secured by a key 55 to the extension 46 adjacent to the bearing 48 for rotation with the shaft 32. The flange 54 is generally disc-shaped in configuration, and it is provided with an internal radial passage 56 connecting an outer port 58 with an inner port 60, which port 60 is in communication with the interior of the hollow extension 46 of the shaft 32. The thick- 3 flange 54, and having its opposite sides engaging said head and said flange in fluid tight or vacuum tight contact therewith, yet being capable of sliding motion rela tive thereto.

The disc 62 is also mounted slidably for rotation on the extension 46 of the shaft 32 adjacent to the reduced portion 50 thereof. The outer periphery of the disc 62 may project slightly beyond the valve head 38 and the ported flange 54, and opposite sides of the disc 62 may be recessed slightly, as indicated at 64, in order to receive said head and said flange in fluid tight engagement.

The disc 62 is provided with a pair of ports 66 extending entirely transversely therethrough on diametrically opposite sides thereof near the outer periphery of said disc. One side of the disc 62 is provided with a pair of arcuate grooves 68, each having one end thereof communicating with one of the ports 66, and having its other end extending to a point adjacent to but spaced from the other port 66. The grooves 68 are symmetrically arranged to extend in opposite directions from the two ports 66, and these grooves each traverse an arc of about 150 along the periphery of the disc 62.

When the control device 36 is in the operating position in which it is depicted in FIG. 3, one of the ports 66 in the central control disc 62 connects the port 58 in the ported flange 54 with a port 70 formed in the valve head 38, which port 70 is connected by a pipe '72 with a source of vacuum (not shown). At this time the other port 66 in the disc 62 is in communication with a second port 74 formed in the opposite side of. the valve head 38 and which is open to the atmosphere. However, at this time the connection with the atmosphere provided by the port 74 has no effect upon the maintenance of the vacuum within the hollow shaft 32 and the transfer dies 30, because this connection is closed by the lower portion of the flange 54. On the other hand, when the control device 36 is in the operating position in which it is depicted in FIG. 4, wherein the flange 54 has been turned 180 from the position in which it is shown in FIG. 3, while the other elements of the device 36 have been held stationary, the hollow interior of the shaft 32 is now placed in communication with the atmosphere by the alignment of the

ports

58, 66 and 74, and the connection to the source of vacuum of port 70 is shut off by the upper portion of the flange 54.

An overrunning type one-way' clutch 76 is mounted on the integral reduced portion 50 of the shaft extension 46 for turning the control disc 62 in one direction only during alternate rotary movements of the shaft 32. The clutch 76 may include a cylindrical inner race 78 secured by a key 80 to the reduced portion 50 of the shaft extension 46, a plurality of wedge-cam rollers 82 held in contact with the outer periphery of the inner race 78 by a light spring 84, and an outer race 86 mounted concentrically in sliding contact with the rollers 82. The outer race 86 is secured to the control disc 62 by a plurality of bolts 88 for movement therewith.

Rotary movement of the shaft 32 in one direction, in which the inner race 78 is carried therewith due to the key 80 connecting this race with the reduced portion 50 of the shaft extension 46, causes the wedge-cam rollers 82 to turn into wedging position wherein they wedge between the inner race 78 and the outer race 86, so that these races travel together. Opposite rotary movement of the shaft 32 turns the rollers 82 into disengaging position wherein they allow the outer race 86 to slide freely with respect to the rollers 82, so that the inner race 78 may continue to turn without carrying the outer race 86 therewith.

In order to prevent the outer race 86 from moving when the cam rollers 82 are in their disengaging position, a friction brake band 90 is held in circumferential contact with a portion of the outer periphery of the outer race 86, as is best shown in FIG. 6. The brake band 90 is urged against the outer race 86 by a pair of springs 92 encircling a pair of bolts 94 mounted on the base 42 at opposite ends of the brake band 98. Due to this arrangement the brake band always remains in frictional contact with the outer race 86, and the frictional contact is suflicient to hold the outer race 86 stationary when the clutch 76 is disengaged, but when the clutch 76 is engaged the driving force thereof overcomes this frictional contact to carry the outer race 86 and the control disc 62 along with the shaft 32. In this manner, the rotation of the control disc 62 is limited to turning in one direction only, in steps of 180, while the ported flange 54 turns alternately in opposite directions also in steps of 180 during the oscillation of the transfer dies 30.

Operation At the start of a complete operating cycle, the transfer dies 30 may be in the upwardly projecting position in which they are shown in FIG. 2, wherein they are ready to receive molded pulp articles transferred thereto from a rotary pulp molding machine, and the vacuum control device 36 at this time connects said dies through the hollow rotatable shaft 32 on which they are mounted with the source of vacuum (not shown). As is best shown in FIG. 3, the vacuum connection is provided by the alignment of the

ports

58, 66 and 78, formed in the flange 5 the central control disc 62, and the valve head 38, respectively. The port 7 Q is connected by the pipe 72 with said source of vacuum to complete the connection. Now, the shaft 32 is turned to carry the dies 30 through an arc of 180 to their inverted, downwardly projecting position where the molded pulp articles are dropped off when the application of the vacuum thereto is terminated. During this motion of the shaft 32 the ported flange 54 is carried therewith, but the other elements of the control device 36 remain stationary, the control disc 62 being held against rotation by the cooperation of the friction band 98 with the outer race 86 of the clutch 76, which race 86 is secured to the disc 62 by the bolts 88. The vacuum connection continues in eflfect as the port 58 is moved away from the port 66 during the turning of the flange 54, due to the registration of the port 58 with the arcuate groove 68 formed in one face of the disc 62. This condition continues while the port 58 transcribes an arc of about and thereupon reaches the opposite end of the arcuate groove 68. The vacuum connection is broken when the port 58 passes beyond the end of the groove 68, but the vacuum momentarily remains in effect within the hollow shaft 32 and the dies 30 while the port 58 moves across the intervening flush portion of the face of the disc 62, until the port 58 reaches the other port 66 which communicates with the atmosphere. Termination of the vacuum in this manner discharges the molded pulp articles from the transfer dies 30.

At the beginning of the second half of the operating cycle, the vacuum control device 36 is in the position in which it is illustrated in FIG. 4, wherein the

ports

58 and 74 are aligned with each other and with one of the ports 66 in the disc 62 to provide communication with the atmosphere. Now, as the shaft 32 is turned in the opposite direction to carry the dies 30 through the arc of back to their original position at the start of the operating cycle, both the flange 54 and the central control disc 62 are turned therewith. The disc 62 is moved by wedging engagement of the rollers 82 between the inner race 78 and the outer race 86 of the clutch 76, and such motion in this direction only is permitted by overcoming the fractional contact between the brake band 90 and the outer race 86. At the conclusion of this half of the operating cycle, the port 58 is once again brought into alignment with the port 70 in the valve head 38, thereby placing the transfer dies 30 in communication with the source of vacuum.

Thus, in the unique valve action provided by control devices embodying the present invention, the disc-shaped flange 54 is turned alternately in opposite directions in steps of 180", while the central control disc 62 is turned in one direction only in steps of 180 along with the flange 54 during alternate movements thereof, and the valve head 38 remains stationary at all times. This arrangement provides effective control with simplicity of structure and minimum wear of moving parts.

It is evident that the three primary control elements, which have been illustrated and described in detail as an annular valve head 38, a disc-shaped flange 54 of unequal thickness and a central control disc 62, may all be made in the form of generally symmetrical discs adapted to co operate with each other. While a specific one-way clutch and a brake therefor have been illustrated and described, it should be understood that other types of one-way clutches and brakes are contemplated as suitable for purposes of the present invention.

Although the invention has been described with particular reference to controlling the intermittent application of a vacuum to oscillatable transfer dies for pulp molding machines, control devices embodying the invention may be employed advantageously for periodically applying pneumatic or other fluid motive power to rotating or oscillating article carrying elements of various type of machines.

It will be obvious to those skilled in the art that vari ous changes may be made without departing from the spirit of the invention and therefore the invention is not limited to What is shown in the drawings and described in the specification but only as indicated in the appended claims.

What is claimed is:

1. In a vacuum control device for pulp molding machines and the like, wherein an oscillatable article carrying element is mounted upon a hollow rotatable shaft which turns alternately in opposite directions, the improvement comprising a first valve element secured to said shaft for turning motion therewith and having a passage communicating with the hollow interior thereof, a second valve element mounted non-rotatably adjacent said first valve element, said second valve element having a pair of ports communicating with a source of vacuum and with the atmosphere, a third valve element mounted rotatably intermediate said first and second valve elements with its opposite sides in contact therewith, said third valve element having a plurality of passages for selectively connecting the passage in the first valve element with the ports in the second valve element, and means for turning the third valve element in one direction only with the first valve element during alternate movements thereof, whereby said valve elements cooperate to connect the hollow shaft with the source of vacuum intermittently.

2. The device defined by claim 1 wherein the first valve element is a ported flange having a passage communicating with the hollow shaft, the second valve element is a valve head provided with said pair of ports, and the intermediate third valve element is a rotatable disc having a pair of transverse passages extending completely through the disc for selectively connecting the passage in the flange with the pair of ports in the valve head.

3. In a vacuum control device for pulp molding machines and the like, wherein an oscillatable article carrying element is mounted upon a hollow rotatable shaft which turns alternately in opposite directions, the improvement comprising a flange secured to said shaft for turning motion therewith and having a passage communicating with the hollow interior thereof, a valve head mounted non-rotatably adjacent said flange, said valve head having one port providing communication with a source of vacuum and having another port providing communication with the atmosphere, a central control disc mounted rotatably intermediate the flange and the valve head with its opposite sides in contact therewith, said disc having passages for selectively connecting the passage in the flange with the ports in the valve head, and means for turning the control disc in one direction only with the flange during alternate movements thereof, thereby intermittently connecting the article carrying element With the source'of vacuum.

4. The device defined by claim 3 wherein the passages in the central control disc include a plurality of transverse ports extending completely through the disc, and a plurality of arcuate grooves formed on one side of the disc and extending in opposite directions from each of said ports to a point adjacent but spaced from another of said ports.

5. The device defined by claim 4 wherein a pair of the arcuate grooves each traverse an arc of about along the side of the disc, and the rotatable shaft together with the flange turns alternately in opposite directions in steps of so that the passage in the flange is maintained in communication with one of the grooves during a substantial portion of the movement of the flange relative to the disc.

6. In a vacuum control device for pulp molding machines and the like, wherein an oscillatable article carrying element is mounted upon a hollow rotatable shaft which turns alternately in opposite directions, the improvement comprising a generally disc-shaped flange secured to said shaft for turning motion therewith, said flange having a radial passage communicating with the hollow interior of the shaft, a valve head mounted nonrotatably adjacent said flange, said valve head having one port communicating with a source of vacuum and having another port communicating with the atmosphere, a central control disc mounted rotatably intermediate the flange and the valve head with opposite sides of the disc in fluid tight slidable contact with said flange and said valve head, said disc having a pair of passages in diametrically opposite portions thereof for selectively connecting the passage in the flange with one of the two ports in the valve head, and a one-way clutch connecting the disc with the shaft during alternate movement thereof for causing the disc to turn in one direction only therewith, thereby intermittently connecting the article carrying element with the source of vacuum.

7. The device defined by claim 6 wherein the pair of passages in the central control disc include a pair of transverse ports extending completely through the disc on diametrically opposite portions thereof, and a pair of elongated arcuate grooves formed in one side of the disc and extending symmetrically in opposite directions from each of said ports to a point adjacent but spaced from the other port.

8. The device defined by claim 7 wherein the pair of arcuate grooves each traverse an arc of about 150 along the side of the disc, and the rotatable shaft together with the flange turns alternately in opposite direction in steps of 180, so that the passage in the flange is maintained in communication with one of the grooves during a substantial portion of the movement of the flange relative to the disc,

9. In a vacuum control device for pulp molding machines and the like, wherein an oscillatable article carrying element is mounted upon a hollow rotatable shaft which turns alternately in opposite directions in steps of 180, the improvement comprising a generally disc shaped flange secured to said shaft for turning motion therewith, said flange having a radial passage communicating with the hollow interior of the shaft, a valve head mounted non-rotatably adjacent said flange, said valve head having one port communicating with a source of suction and having another port communicating with the atmosphere, a central control disc mounted rotatably intermediate the flange and the valve head with opposite sides of the disc in fluid tight slidable contact with said flange and said valve head, said disc having a pair of transverse ports extending completely through the disc on diametrically opposite portions thereof for selectively connecting the passage in the flange with one of the two ports in the valve head, one side of said disc having a pair of elongated arcuate grooves extending symmetrically in opposite directions from each of said ports through an arc of about 150 to a point adjacent but spaced from the other port, and a one-way clutch mounted on the shaft and adapted to turn the disc with the shaft in one direction only during alternate turning movements thereof,

References Cited in the file of this patent UNITED STATES PATENTS Chaplin May 23, 1916 Giorgini May 4, 1954