US3070212A

US3070212A - Stacking machine

Info

Publication number: US3070212A
Application number: US61700A
Authority: US
Inventors: Lyle F Shabram
Original assignee: Consolidated Thermoplastic Co
Current assignee: Consolidated Thermoplastic Co
Priority date: 1960-10-10
Filing date: 1960-10-10
Publication date: 1962-12-25
Anticipated expiration: 1979-12-25
Also published as: GB933897A

Description

Dec. 25, 1962 F. sHABRAM STACKING MACHINE Filed Oct. l0, 1960 5 sheets-Sheet 1 I YLE F. SHABRAM HAM/s, K/E

F/Cl.

/N VEN TOR BY H/$ ATTORNEYS CH, RUSSELL 8 KERN Dec. 25, 1962 L.. F. SHABRAM 3,070,212

STACKING MACHINE Filed Oct. l0, 1960 5 Sheets-Sheet 2 Bv H/.s ATTORNEYS HAM/s. msc/1. Russe/.L a frm/v.

Dec. 25, 1962 L. F. sHABRAM sTAcKING MACHINE 5 Sheets-Sheet 3 Filed Oct. 10, 1960 /Nl/E/VTOR YLE F. SHABRAM BV- H/S ATTORNEYS HARRIS, K/ECH, RUSSELL 8 KERN Dec. 25, 1962 L. F. sHABRAM 3,070,212

STACKING MACHINE Filed Oct. 10, 1960 5 Sheets-Sheet 4 /NVENTOR I YLE F. SHABRAM BV H/S ATTORNEYS HARP/.5, K/ECH, RUSSELL 8/(ERN Dec. 25, 1962 L. F. SHABRAM STACKING MACHINE Filed oct@ 1o. 1960 f5 Sheets-Sheet 5 F G. 8.

/NVE/vron I YLE F. SHABRAM BY 'Lf/` ATTORNEYS HARRIS, K/ECH, RUSSELL KERN United States Patent Oitice 3,070,212 Patented Dec. 25, 1962 3,070,2l2 STACKIWG MACHINE Lyie F. Shabram, Danville, Calif., assignor to Consolidated Thermoplastics Company, Stamford, Cmnm, a corporation of Deiaware Filed st. I0, 1960, Ser. No. 611,700 4 Claims. (Cl. 198-35.)

This invention relates to stacking machines and, in particular, to a machine for taking articles from a relatively high velocity belt or the like and depositing the articles at an outlet device at a relatively low velocity. The machine is especially adapted for use with high speed bag-manufacturing equipment such as that shown in my copending application entitled Apparatus for Forming Articles From a Web, Serial No. 70,481, tiled November 2l, 1960, and assigned to the same assignee as the present application. But, of course, it is not Llimited to this one use.

It is an object of the invention to provide a machine for picking up articles, such as plastic bags, from acontinuous high velocity source and depositing the articles on a low velocity or stationary outlet device. Another object is to provide a stacking machine having a variable release point so that articles can be deposited in vertical stacks on a stationary outlet or in closely overlapped layers on a slow moving outlet using a fixed release point, and in vertical stacks on a moving outlet using an oscillating release point.

It is an object of the invention to provide a machine for removing articles from .a continuous source and including a plurality of arms with each arm having an article-gripping section and a drive section, a track having an arcuate section and a relatively straight section, means for engaging the drive section of each of the arms and driving the arms around the track with the articlegripping section projecting from the track whereby 'the gripping section of an arm has a relatively high velocity when the arm is traversing the arcuate section and a relatively low velocity when traversing the straight section, and with the gripping section of an arm passing through a iirst position adjacent the source while traversing the arcuate section and passing through a second position adjacent the outlet while traversing the straight section, and control means for energizing the article-gripping section of each arm While the arm is passing from the first position to the secondI position to remove an article from the source at the rst position and deposit the article on the outlet at the second position.

It is an object of the invention to provide a machine for removing articles from a high velocity belt and stacking the articles on a low velocity belt including a plurality of arms with each arm having an article-gripping section and a drive section and with the gripping section including a vacuum line with a plurality of outwardly directed inlets, a track having an 'arcuate section and a relatively .straight section, means for engaging the drive section of each of the arms and driving the arms around the track with the article-gripping section projecting from the track whereby the gripping section of fan arm has a relatively high velocity when the arm is traversing the `arcuate section of the 'track and a relatively low velocity when traversing the straight section, and with the gripping section of an arm passing through an article-pickup position adjacent the high velocity `belt while traversing the arcuate section and passing through an article-release position adjacent the low velocity belt while traversing the straight section, yand control means for connecting a vacuum source to the vacuum line of each arm while the armis passing from the -article-pickup to the release position. yAnother objectis to provide a stacking machine wherein the article-gripping section .of

section of the track and the vacuum is shut off to permit the article to be deposited onto thelow velocity belt. A further object is to provide a stacking machine including :a source of air lunder'pressure in the central area of 'the vmachine vto provide Yan outwardly directed air current over the arms as yan aid in controlling the relativey large and flimsy articles as they are moved from one belt to the other.

vThe invention also comprises'novel details of construction Vand novel combinations and arrangements of parts, ywhich will more fully appear in the course of the following description. The drawings merely show and the description merely describes a preferred embodiment of :the present .invention lwhich is given by Way of illustration or example.

Inthe drawings:

.FIG. l is a side elevation of a plastic bag-manufacturing apparatus having the stacking machine of the invention at vthe Aoutput Aend thereof;

FIG. 2 is an end View taken along the line 2 2 of PIG. 1;

lFIGS. 3 and 4 comprise an enlarged sectional View taken along the line 3 3 of FIG. l.;

FIG. A5 is a sectional vview taken along the line 5 5 of FIG. 3;

FIG. 6 is a sectional Aview taken along the line 6 6 of FIG. 3;

FIG. 7 is a sectional view taken along the line 7 7 of `FIG. 3;

FIG. 8 is la sectional view taken along the line 8 8 of FIG. 3;

FIG. '9 is a sectional view taken along the line 9 9 of FIG. 3;

FIG. y1,() is a sectional view taken along the line 10 10 of FIG. 4; and

FIG. ll is a partial view taken along the line M li lof FIG. 4.

FIGS. l and 2 vdepict a bag-making machine 14 having a stacking machine l5 positioned at the output end thereof. The bag-making machine i4 includes a drive motor 16, a heat-sealing drum 17, an endless belt IS, and a roll stand i9, and is described in detail in my aforesaid copending application. The motor 16 drives the drum 17 through a belt 29 yand gear 2l. The drum, in turn, drives the endless belt 1% which passes between

rolls

22, 23, over rolls 24., 25, around the drum I7, over rolls 26, 27 23, and over rolls 29, Sti of a belt-tensioning device. In the particular embodiment shown herein, the stacking machine l5 and a conveyor belt 3d are also driven from the motor I6, via the belt 2), a worm gear 32, a shaft 33, right angle drives 34, 35 Vand a chain 36. The belt '3l and a variable speed transmission 37 are driven from the chainSii, the transmission 37 driving ,the

stacking machine l5 through another chain 38. This type of drive provides a direct speed relation between the drum 417, the conveyor belt 31 and the stacking machine 15, but of course any suitable `drive may be used for each of the units.

In the operation of the machinery, a roll 4d of material such `as polyethylene film is mounted in the roll stand 19 and a VVstrip 4l of the material, which is ordinarily folded double, is fed from the roll 4t) into engagement with the endles belt 1'8 between the rollers 22 23. The drum 17 carries appropriate heat-Sealing electrodes which form the strip of material into the desired articles. Typically, the .product of 'the machine will be rectangular bags 42 having .a folded edge Vat the bottom and Vheatsealed edges at each side. The heat-sealing electrodes of the drum 17 may separate the bags from each other or may only partially separate them so that a continuous web of material leaves the drum. The stacking machine of the present invention is suitable for use with either type of operation.

The stacking machine includes a plurality of arms 5t), each having means for gripping a bag at the extremity thereof. The arms are driven around a track having an arcuate section and a straight section so that t e extremities of the arms move at a relative high velocity while an arm is traversing the arcuate section and at a relatively low velocity when an arm is traversing the straight section of the track. The stack-ing machine is positioned relative to the source of articles, here the belt 18 of the bag-making machine 14, so that an arm is traversing the arcuate section of the track when the extremity thereof is adjacent the source. |The speed of the stacking machine is adjusted so that the velocity of the arm extremity is about the same as that of the belt 18 so that the arm can easily pick up the bag from the belt. The stacking machine is also positioned relative to the outlet, here the conveyor belt 13, so that the arms are traversing a straight section of the track when the arm extremity is over the outlet. Then the arm extremity is moving at a much slower velocity and the bag can be deposited on the belt in any of several styles to be described hereinbelow.

The stacking machine is shown in greater detail in FIGS. 3 and 4 and the remaining figures. The machine includes

vertical frame members

51, 52 carrying

bearing blocks

53, 54 respectively. A stepped tubular shaft 55 is mounted betweenV the frame members in the bearing blocks and a solid shaft 56 is positioned within the tubular shaft 55 and rotates in bearings mounted in the

bearing blocks

53, 54.

Each of the arms 50 is in the form of a U-shaped tube having a fitting 59 at one end and a fitting 60 at the other. Each of the fittings 59 is. fixed between T-shaped links of a link chain belt 61 and each of the fittings is similarly mounted in a belt 62. The conA struction and operation of the

belt

61, 62 is essentially the same and the belt 62 will be described as typical. This structure is best seen in FIGS. 5, 8 and 9.

The chain 62 runs over

sprockets

63, 64 carried on

shafts

65, 66, respectively. The shaft 65 is mounted in bearings in the bearing block S3 and the shaft 66 is mounted in bearings in the bearing block 67 which is also mounted on the frame member 51. The block 67 is slidable horizontally relative to the block 53 for adjusting the belt tension, fine adjustment being provided by screws 68 carried in the Iblock 53. The shaft 65 is driven from the variable speed transmission 37 via the belt 38 which runs over a sprocket 70. The corresponding shaft for the chain belt 61 on the other side of the machine is driven from the shaft 65 through

gears

71, 72, the shaft 56, and a corresponding set of gears indicated at 73 (FIG. 4). The two

sprockets

63, 64 provide a track along which the arms 53 travel, the arms following an arcuate path when the belt engages the sprocket and following a straight path between the sprockets.

lf desired, means may be provided with the belt track to provide a smooth transition between the arcuate section and the straight section. One such means is shown in FIGS. 5 and 9 in the form of a shoe 74 mounted on the frame member 51 and within the loop of the belt 62. The shoe is provided with a cam surface 75 which engages the belt while moving through the arcuate section of the path and provides a gradual change of curvature to the following straight section. A simi-4 lar shoe is provided for the belt 6l on the opposite side of the machine.

A plurality of slits 77 is provided along the outer edge of the bight of ea :h of the U-shaped arms 59 to provide means for gripping a oafT and picking the bag from the belt 18. A vacuum source is connected to each of the itubular arms through the fitting 69, providing a suction at the slits 7'7. The vacuum on each individual arm is controlled so that the vacuum is turned on prior to arrival of an arm at the bagpickup position, indicated at A of FIG. 5, and is shut off when the arm is at the bag-deposit or release position, indicated at B. Each of the fittings 6G may be connected to a corresponding port 7S in a port plate 79 through a fiexible line Si?. The port plate 79 is fixed to a sleeve Si which in turn is mounted on the tubular shaft 55 with bearings '82. The sleeve 8l includes a spur gear S3 driven through an idler gear S4 from another gear 85 carried on the shaft 65 for rotation of the port plate in synchronism with the arms 59.

Control of vacuum to the individual ports 78 and, hence, to the individual arms 5G is carried out through a manifold plate S7 fixed on the shaft 55. The manifold plate 87 is positioned against the port plate 79 with a valve seat SS of Teflon or other suitable material positioned therebetween. A plurality of circumferentially spaced pins 89 is carried in the port plate 79, riding in an annular groove 90 in the manifold plate to maintain alignment of the two plates. A fiexible line 91 (FIGS. 2 and 7) provides communication between a manifold passage 92 in the manifold plate and the interior of the tubular shaft 55. Another line 93 which may be coupled to a remote vacuum source, is mounted in the bearing block 53 for communication with the interior of the tubular shaft 55 (FIGS. 3 and 8). O-

rings

94, 95 provide seals between the

shafts

55, 56 to provide a closed flow path from the manifold passage 92, through the line 91 and the shaft 55 to the line 93. The manifold passage 92 occupies about 180 of arc so that the vacuum source is connected to an arm at some time before the arm approaches position A and is disconnected when the arm is at position B. By having the passage 92 cover a greater portion of the revolution than is required for moving from position A to position B, the specific location of position B can be varied without affecting the location of position A.

Another manifold passage 96 may be provided in the manifold plate S7 to vent the arms to the atmosphere atA an opening 97 for release of the bags. A source of air under pressure can be connected to the passage 96 in the same manner that the vacuum is connected to the passage 92 to provide an air blast at the slits 77 in the arms to accelerate release of the bags if desired. It has been found that such is not necessary in most applications of the machine. Also, the passage 96 may be used to direct heating or cooling air through the arms during this portion of the operating cycle.

A lever 98 is fixed in a ring 99 mounted on the tubular shaft 55 and provides for rotation of the shaft and the manifold plate 87 relative to the frame of the machine. The lever 98 may be manually operated or may be motor driven as desired. Rotation of the lever provides the above-discussed adjustment of the location of point B where the vacuum is shut off from the arms.

In the handling of lightweight fiexible articles such as Very thin film polyethylene bags, it has been found that the stacking operation is facilitated by providing a continuous outward flow of air past the arms 50. One arrangement for providing the outward air fiow, which is similar to the arrangement for the vacuum source, is shown in FIG. 4. A plurality of openings 100 is provided in the tubular shaft 55 to the right of the O-ring seal 94. An inlet line 161 is fixed in the block 54 providing a flow path from an external air source to the interior of the tubular shaft 55 between the seal 94 and another O-ring seal 192. ln an alternative arrangement, an electric motor-driven blower could be mounted directly on the shaft 55 with the blower inlet connected to the manifold plate 87 to serve as the vacuum source and with the "antonin blower discharge providing the outwardly directed air llow past the arms of the machine. v

The operation of the sta-cking machine is best seen in conjunction with FIGS. l, 2 and 5. In a typical installation, the belt -18 of the bag-making machine will be moving at a rate of iive hundred to eight hundred feet per minute while the outlet conveyor belt 31 may move at less than one tenth this speed, he about thirty-tive feet per minute. A continuous line of bags 42 will be carried along by the belt over theroller 26 and over the roller 27 and past the position A. The stacking machine is located so that the extremity of an ar-rn touches or almost touches a bag adjacent 4its leading edge. At this point, the arm is moving over an arcuate section of 'the ytrack so that the extremity is travelling at'a relatively high velocity. Also, the vacuum source is connected to the arm so that the arm will pick up the bag from the belt. It is preferred to pick up the bags from the underside of the high speed belt so that they may be dropped onto the low speed belt and this is easily accomplished with the present machine as the bags are held to the belt by the static charge thereon until pulled away by the arm. As indicated previously, the bags may lbe severed from each other or may be only partly severed. With partly-severed bags, it is preferred to have the extremity of an arm moving at a slightly higher velocity than the belt at the pickup position so that a tension force is applied to the junction between the bags for severing the bags.

Each bag is carried from position A to position B at which time the vacuum in the arm is cut oit and the bag drop-s onto the belt 31. The outward air currents, indicated by the arrows in FIG. 5, tend to push the trailing edges of the bags outward and prevent a following bag from being stacked underneath a preceding bag. When the belt 3l is run at a steady slow rate and the vacuum is cut olf at the same point for every arm, the bags are stacked on top of cach other with each bag overlying a .major portionof the next lower bag, the overlap being a function or" the size of the bag and the relative velocities of the high speed and low speed belts. In an alternative mode of operation, the belt 31 may be advanced stepwise with the belt remaining stationary for receiving a vertical stack of bags and then being rapidly advanced approximately one bag length to receive another vertical stack oi bags.

In another alternative mode of operating the mechanism, the lever 98 may periodica-ily be shifted and then returned to the initial position to provide a p-eriodic decrease in the amount of overlap which serves as an indicator for a predetermined number of bags, permitting the group to be lifted from the belt as .a unit. in another alternative mode of operation, the lever 98 may be advanced to move the point B forward at the same rate as the belt 31 so that successive bags are deposited in a vertical stack. After a stack of predetermined height has been created, the lever is rapidly returned to the initial position and then advanced at the belt rate to provide a new vertical stack adjacent the preceding vertical stack. Of course, other outlet devices can be substituted for the conveyor belt 31 to receive the bags from the slowly moving arms.

Although exemplary embodiments ofthe invention have been disclosed and discussed, it will be understood that other applications of the invention are possible and that the embodiments disclosed may be subjected to various changes, modications and substitutions without necessarily departing from the spirit of the invention.

I claim as rnv invention:

l. In a machine for removing articles from a relatively high velocity belt and stacking the articles on a relatively low velocity belt, the combination of: a plurality of arms, each of said arms having an article-gripping section and drive section, said gripping section including a vacuum line with at least one outwardly directed inlet; a track having an arcuate section and a relatively straight section;

means for engaging the drive section of each of said arms and driving said arms around said track with the articlegripping section projecting radially from said track, whereby the gripping section of an arm has a relatively high velocity when the arm is traversing the arcuate section of the track and a relatively low velocity when the arm is traversing the straight section, and with the gripping section of an arm passing through an article pickup position adjacent the high velocity belt while traversing said arcuate section and passing through an article-release position Iadjacent -the low velocity belt While traversing said straight section; and control means actuated as a function of position of an arm along said track for connecting a vacuum source to the vacuum line of each larm while the arm is passing from said article pickup position to said release position,

2. In a machine for removing articles from a relatively high velocity belt and stacking the articles on a relative-ly low velocity belt, the combination of: a plurality of arms, each of said larms having an article-gripping section and drive section, said gripping section including a vacuum line with at least one outwardly directed inlet; a track having an arcuate section and a relatively straight seotion; means for engaging the drive sectio-n of each of said arms and driving said arms around said track with the article-gripping section projecting radially from said track, whereby the gripping section of an arm has a velocity approximately that of the high 'Velo-city belt when the arm is traversing the arcuate section of the track and a velocity approximately that of the lo-w velocity belt when the arm is traversing the straight section, and with the gripping section of an arm passing through an article-pickup position adjacent and below the high velocity belt while traversing said arcuate section and passing through an article-release position adjacent and above the low Velocity belt while traversing sai-d straight section; and control means actu-ated as a function of position of an arm along said track for connecting a vacuum source to the vacuum line of each arm while the arm is passing from said article pickup position to said release position.

3. In a machine for removing film-like articles from a relatively high velocity source and depositing the articles in overlying relation on an outlet, the combination of: a plurali-ty of arms, each or" said arms having an article-gripping section disposed substantially orthogonal to a drive section, said gripping section including a vacuum line with at least one outwardly directed inlet; a track having an arcuate section and a relatively straight section; an endless belt riding on said track and engaging the drive section of each of said arm-s for driving said arms around said track with the article-gripping sections projecting outwardly from said track and enclosing a zone as they travel around said track, whereby the gripping section of an arm has a relatively high velocity when the arm is traversing the arcuate section of the track and a relatively low velocity when the `arm is traversing the straight section, and with the gripping section of an arm passing through an article-pickup position adjacent the source while traversing said arcuate section and passing through an article-release position adjacent the outlet while traversing said straight section; control means actuated as a function of position of an arm along said track for connecting a vacuum source to the vacuum iine of each arm while the arm is passing from said article pickup position to saidV release position; and a sotnce of air under pressure positionedwithin said zone for directing air currents outwardly between said gripping sect-ions urging the articles into the overlying tween spaced drive members, said gripping section including atleast one outwardly directed inlet; a track having an arcuate section and a relatively straight section; means for engaging the drive members of each of said arms and driving said arms around said track with the article-gripping section projecting radially from the track and travelling along a path enclosing a zone, with the radius of the path of the article-gripping section many times that of the track in the arcuate section ywhereby the gripping section of an arm has a relatively high velocity when the arm i's traversing the arcuate section of the track and a relatively low velocity when the arm is traversing the straight section, and with the gripping section of an arm passing through a rst position adjacent the source at substantially the velocity of the source while traversing said arcuate section and passing through a second position adjacent the outlet at a greatly reduced velocity While traversing said straight section; control means for connecting a vacuum source to each arm while the arm is passing from said rst position to said second position for gripping and transporting an article; and means positioned within said zone for directing an air stream outwardly between said gripping sections of said arms while said vacuum source is connected to the arms.

References Cited in the file of this patent UNITED STATES PATENTS Magnani Jan. 23, 195k