US2973612A

US2973612A - Bag opener

Info

Publication number: US2973612A
Application number: US566664A
Authority: US
Inventors: William S Mcgowan
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-02-20
Filing date: 1956-02-20
Publication date: 1961-03-07
Anticipated expiration: 1978-03-07

Description

March 7, 1961 w. s. MOGOWAN 2,973,612

BAG OPENER Filed Feb. 20, 1956 s Sheets-Sheet 1 WILL/AM SMQGMAM //1 Vf/V 7' 0,?

5y MM March 1961 w. s. MCGOWAN 2,973,612

BAG OPENER Filed Feb. 20, 1956 s Sheets-Sheet 5 83- DRIVE CRANK VACUUM r a 85 FUNNEL 5A6 PICK I 87... BAG

- ope/v .J 58 LII-7' II: IE EI WILLIAM S.M6owA- 1N VEN TOR.

United States Patent BAG OPENER William S. McGowan, 23 Villa St., Salinas, Calif. Filed Feb; 20, 1956, Ser; No. 566,664

. 18 Claims. c1. 53-384) The present invention relates to a machine for opening bags and for holding such bags, after being opened, in a position suitable for filling material thereinto. There have been many machines for this purpose which have been successful for use with paper bags, but the newer bags made of cellophane, polyethylene, or other plastic materials present physical conditions which the paper bag. machines cannot handle, such as lightness, flexibility, and adherence.

Thus it is an object ofthe. present invention to construct and operate a bag opening machine which will operate on the newer plastic bags to open them and to present them in position for filling.

Another object of the present invention is the devising of a bag opening machine which will open a plurality of bags at a time.

- A further object of the present invention is the construction of a bag opening machine which will be intermittent in at leasta portion of its operationso that while a pluraility of bags are being opened, previously opened bags may be filled.

Another object of the invention is to open and place bags on a series of funnels thruwhich the bags are to be filled.

Another object of the present invention is the construction of a machine in which bags are opened and moved onto traveling funnels which are fixed in position while the bags are placed thereon.

A still further object of the present invention is th construction of ajcollapsible funnel for use in holding bags when opened and while being filled.

Yet anotheriobject of the invention is the construc-' tion of a machine'in which an arm which picks up a bag from the top of .a pile thereof serves to carry such bag onto a funnel.

A further'object is to open a bag by separating a pair ofarms where Ioneof such arms has picked such bag off the top of a stack of bags.

Still another object of the invention is the establishment of particular ratios between chain link length, funnel spacing, and chain drive drum circumference.

The abovelme'ntioned and other defects of the prior art are remedied and these objects are achieved, briefly, by a machine in which an endless chain or even a large wheel has evenly spaced therealong a series of collapsible funnels which are indexed by a bag opening station and then by a bag filling station. At the bag opening station the funnels are temporarily collapsed while receiving therearound thebagsa The funnels are progressed and again collapsed after leaving the filling station to allow removal of the bags therefrom At the bag opening station the bags are picked olf of piles thereof by a" suction, or air, pickup arm which swings to adjacency with the line of funnels where it is overtaken by a suction bag opening arm. The arms separate to open the bags and then the pivots for the arms arefraised to place the bags n the collapsedfunnels- The funnels then open and the "ice pivots are lowered to clear the funnels before pivoting to again pick up bags.

A detailed description of a machine embodying the above outline is given hereinafter and is depicted in the accompanying drawings, in which:

Figure l is an end elevational view of the machine forming the subject matter of the present invention.

Figure 2 is an enlarged elevational View of the funnel and some of the adjacent parts, found in the other figures.

Figure 3 is a plan view of such machine.

Figure 4 is a side elevational view of the machine.

Figure 5 is a diagram showing the comparative operational steps related to 360, one cycle of the various parts of the machine.

The parts of the machine are generally supported and held together by means of an angle iron frame 11. Above the top of the frame are two coplanar spaced apart

drums

12, 13, or pulleys. In Figures 3 and 4, the right hand drum 12 is the drive drum and the left hand one 13 is the driven drum, which is driven from the drive drum by means of a pair of spaced apart

endless chains

14, 15, each placed around and between the drums. The drive drum may have inserted in its outer circumferential face a few pegs 16, acting as sprocket teeth, to engage the chains and prevent slippage thereof with respect to the drive drum. Also, the drums may have a lower edge flange 17 which prevents the lower chain 14 from dropping olf the drum. The drive drum 12 has secured thereto axially thereof a shaft 21 that is provided with a bearing 22 secured to the frame 11. The driven drum 13 is mounted for rotation in a flanged plate 24 that is secured to the top of the frame 11 for adjustable movement on the common diameter of the two drums so that the tension of the chains may be regulated. The chains are bridged apart by bars 31 secured between and to the chains, and normal to the chains. These bars are evenly spaced along the chains, preferably a distance which is a whole multiple of a chain link length. The circumference of each drum, particularly the drive drum, is preferably equal to a whole multiple of this bar spacing so that one revolution of the drive drum will find the bars in the same positions as at the start of the revolution. Also it is desirable that this whole multiple of bar spacing be wholely divisible by the number of bags to be opened at each indexing of the drive. In the present showing, the link length is five-eighths inches; the link multiple between bars is ten; the bar multiple is twelve; and the bags to be opened at each indexing is three. That is ten times the link length gives the bar spacing; and the bar spacing times twelve gives the circumference of the drive drum.

To each of the bars 31 is secured a collapsible funnel 32 having a tubular rim'33 with a flared top edge 34 which is fastened to its related bar 31 by an angle clip 35 having a leg flat against the bar and bolted thereto. A collapsible skirt for the funnel is formed of two

skirt halves

36, 37. Each half is in the general form of an isosceles triangle bent to the form of part of a cylinder with the altitude of the triangle parallel'to the axis of such cylinder and the diameter of the cylinder being greater than the diameter of the nm 33. The vertices of the equal angles of each half are pivotally pinned by pins 38 to the lower part of the rim 33 so that the two halves are in opposition, their base portions substantially 43 that is pivoted on a pintle 44 that passes thru the ends 46 of a U-shaped bracket 47 secured midway thereof transversely of and to the angle clip 35. The stem 48 of the Y-shaped crank extends upward to a position above the upper chain 15. A coil spring 49 is wrapped around the pintle 44 with one end thereof engaging the Y-shaped crank 43 and the other end engaging the U-shaped bracket 47 and tensioned to urge the stem 48 inwardly of the machine and, hence, the skirt halves to open posi tion. In open position, each skirt half contacts the lower end of a stop bar 50 that has its upper end secured to the funnel rim 33 above the skirts, and its lower end bent away from its contacting skirt half.

The above construction and arrangement of the drums, chain, and funnels gives two straight runs, or lines, of funnels, one on either side of the machine. One run is called the bag feed, or bag opening, run, or station, and the other is the bag fill run. Below the lower end of the funnels of the bag feed run a distance equal to about the length of the bags to be opened is a bag platform 51 that is supported by extension arms 52 of the frame 11. In the present form of the invention there are placed apart on this platform three bag magazines formed by the pegs 53. The spacing of these magazines is that of the funnels on the chains; and their location along the run is that of each directly below a funnel when the chain is without movement, between the periodic indexing thereof. A stack of bags is placed in each magazine with each stack equal to the other in height, or number of bags, with the open ends of the bags 54 away from the frame 11.

A pair of lift arms 56 extend across the frame 11 at about the level of the platform. Each arm 56 is pivoted to the frame adjacent the fill side and extends across the frame to project slightly beyond the opening side to extend below the line of funnels thereabove. The free end of each arm carries a pivot block 58. Journaled in and extending between these blocks are parallel

hollow shafts

60, 61. These shafts are approximately directly below and parallel to the opening run of funnels. The left ends of these shafts are open and project well beyond the left pivot block. The right ends of the shafts are closed. Each shaft has secured thereto a U-shaped pipe so that the shaft and pipe form a rectangle. The pipe interior is in communication with the shaft interior. Each pipe revolves with and about its shaft. The rectangle having its shaft 61 closest to the frame 11 forms a bag pick, or pickup arm 66, and the other rectangle forms a bag open, or opening arm 67. The sides 68 of the pick arm 66 are the same length as the sides 69 of the open arm but the

shafts

60, 61 are so spaced that when the arms are in their lowered position, that shown, the bars 70, 71, which are parallel to the

shafts

60, 61, are in a separated position. In this lowered position the bar 70 of the pick arm contacts the bags adjacent their open ends, and the portions of the pick arm 68 contacting the bags is provided with openings 72 so that if a negative air pressure, suction, is had in the arm a series of three bags will adhere thereto. In the position shown in Figure 3, the openings 72 of the pick bar 70 are in its underside while similar openings 73 in the opening bar 71 are in its upper side. When these arms are raised, the openings 72 of the pick bar are in opposition to the openings 73 of the opening bar. The

shafts

60, 61 are so placed in their pivot blocks 58 and the

rectangles

66, 67 are so proportioned that this takes place and so that when lowered, the pick arm may pass thru the opening arm as shown in Figures 1 and 3.

On the fill side of the machine and located below and parallel to the chains is an endless fill-conveyor 74 upon which the bottom ends, the closed ends, of the bags may rest while being filled. This conveyor extends between and around a pair of

pulleys

76, 77, each of which is secured to an end of the frame and outboard thereof.

There is a power source and clutch, not shown, which m a P y 81 o at s. a Cam shaft 82 having. thereon a crank 83 and a plurality of earns 84, 85, 86, 87, and 88, arranged and numbered from top to bottom. The shaft 82 is journaled and supported in bearings secured to members of the frame 11. The shaft 82 is near the center of the frame 11. A direct connection to the power source may furnish the power for a pump, not shown, which provides suction to the

hollow shafts

60, 61.

Before further describing the drive mechanisms, it may be well to describe the effects of the crank and cams, and their shapes.

Figure 5 may be called a sequence, or cam, diagram, as the curves of this figure not only illustrate the general shape of the crank and each cam, the function it is to cause the machine to perform, but, also, the relative timing of each such function to the others. Each of the six curved lines of this figure is given the number of the drive, crank and earns; whose function and shape it represents. The start of the curves has been taken at the position of the cam shaft 82 where most of the followers for such cams are at the low points of such cams. This position of the shaft is called the zero point of a cycle, which cycle is one revolution of the shaft, 360, and each of the curves extends from this zero position thru 360, which is again the zero, or home, position.

The only drive on the cam shaft 82 which does not have its follower at its low point in home position is the chain drive crank 83. At home position, the chain has moved from a position of rest the distance of the. spacing of one of the funnels. From home position, this movement of the chain continues for a distance of twice the spacing of one of the funnels, at which position, 120, the crank is at the top of its throw, the high point on the curve 83. Movement of the crank from the high of its throw to its low, 300, does not effect movement of the chain. This is its rest time.

The critical operation of the machine is that, of picking up the bag. The rate at which this can be done determines the speed at which the machine can be operated, and all other movements of the machine must be timed and related to this picking operation. The speed of this operation is critical because the bags can be separated only at a rate which wi l allow air to enter between the bag being picked otf the top of a stack and the one next below, and which will allow the natural cohesiveness of the bags to be dissipated, without pulling the next below bag and lower bags off the stack. As these bags are very light in weight, naturally cohesive, and very flexible, this is a difficult operation not encountered in prior bag opening machines designed for use with paper bags. For the above reasons, the initial acceleration of the pick cam 86 is very low, as pictured in Figure 5, so as to give plenty of time for the initial separation of the bags. This cam actuates the pick arm 66 which in zero position has its bar 70 resting on the stack of bags adjacent the open ends thereof and suction on the openings 72 in the bar 70 so that as the arm is raised a bag will adhere to the bar and be lifted off each of the bag piles. These bags are raised until the arm is near 66a the vertical, parallel to the line of funnels, and just below and outside of such funnels, In raising to this last position, the pick arm passes thru the bag open arm 67 which follows the pick arm up under actuation of its cam 87 and open arm 67a overtakes it in this last position, 110, where the bag open bar 71 contacts the bags in opposition to the pick arm bar 70 so that the suction on the bag open ports 73 in the bar 71 secures the bags to the bag open bar 71. The pick arm then proceeds across the line of funnels to the inside thereof 66b as is shown by a further rise, in the cam curve. This opens the bags. rest, 120 to 300.

The pick and open cams, 86, 87 then rest, 120 to 200, while the lift cam 88 functions, 120 to 200, to actuate the lift arm 56 to raise the pivot blocks 58, and, hence, the pick and open arms and the bags 54 secured thereto to a position 660, 670, where the mouth, or neck, of

Thechainseach bag isaround the skirt of a funnel. At this point, 190, in the cycle, the funnel cam 85, which had at about 120 collapsed, or drawn together 36a, 37a, Figure 2, the

skirts

36, 37 of each of the three funnels in line with the raised bags, releases them so that they spread and engage the inside of the bags adjacent their openings. Also, in opening, each skirt clamps the bag wall against one of the stops 50 to further secure each bag to its funnel, and prevent stretching and tearing of the bag upon such funnel opening.

With the funnels open and the bags secured thereto, the pick arm moves, 200, inward 66d of the machine away from the funnels as is shown by a further rise in the curve 86 to its highest point, and the open arm moves away from the funnels as shown by the drop in the curve 87 from its highest point. The lift cam curve then drops from its high point to lower the arms and to allow the pick arm to drop and clear the funnels and bags which bags, the chain drive crank 83 may start, 210, to move the chain. Certainly, this action may start as soon as the lift cam has dropped, 280, the pick arm so that its bar 70 will clear the funnel skirts. This position is near the lowest part, 300, of the drive crank curve 83. As previously stated, the drive crank 83 moves the chain about the distance of one funnel before it reaches zero position. The cycle is then ready to repeat which it does as long as power is applied to the cam shaft 82 to etfect rotation thereof.

The bags are opened and placed on the funnels three at a time and then move around the machine to the fill side where they may be filled three at a time while the chains are at rest. The conveyor 74 is driven in time with the chains and serves to support the bags while they are being filled. As the bags move away from the fill position and leave the conveyor 74, the skirt of each funnel in turn is collapsed by contact of the funnel crank stem 48 with a fixed bag release cam 91. The care of the bags past this point and mechanisms for filling the bags,-form no part of the present invention and such are not shown here.

The crank and each of the various cams secured to the cam shaft 82 is secured thereto in spaced apart relationship, and each of the cams has coacting with it a cam follower arm, or lever. These levers are of the same-length and shape, and all are pivoted to the frame 11, by a long pin 93. This pin 93 is vertical, and, so, the cam follower arms are stacked one directly above the other. This pin is located adjacent a corner post of the frame, the post near the filled conveyor 74 and the drive drum 12.

The drive crank 83 thru a link 94 drives a follower arm 95. This follower arm is located above the frame 11 with a downward bend to the crank link 94. The arm 95 is pivotally secured by a pin 96 to the top side bar of the frame 11 adjacent the fill side. The pin 96 is near the middle of the side bar and thearm extends across the frame. The free end of the arm is pinned to a drive pawl 97 by a pin 98. This pawl extends along the opening side of the frame and rests on top of frame cross members for sliding movement thereon. Also, the pawl lies below and close to the drive drum 12 where its notched end 99 will engage one of four drive pins 101 secured to and below the drive drum 12. These drive pins 101 are spaced from the drum shaft 21 90 apart circumferentially of The t 6 drive crank 83, link 94, follower arm 95, the pawl 97, and the drive pins 101 are so shaped and located that each turn of the cam will cause the pawl to move and drive the drum a quarter turn and thereby the

chains

13, 14 the distance of three funnels. The zero position of those parts is shown by the phantom pawl 97a and drive pin 101a. On its return stroke, the free end portion of the pawl rides on the drive pin it is to drive next until near the end of the return stroke'the pin engages in the notched end 99 of the pawl. The pawl is held against the drive pin by a spring 102 secured between the pawl and its follower arm 95. The notched end 99 has enough overhang 103 so that on the return the notch may override the pin a short distance.

The vacuum follower arm 105 for the vacuum cam 84 is located below the drive crank 83 and the drive pulley 81, and below the frame cross members upon which the drive pawl 97 rests, and is the next lower arm to the drive follower 95. The free end of the vacuum follower arm and each of the free arm ends of the followers therebelow, rest and slide on a separate guide strip or angle iron 106 which extends between the corner posts of the frame below the idle drum 13. The free end of the vacuum follower 105, inside the guide 106, is connected by a link 107 to the handle 108 of an air valve 109 which, to 345 of the vacuum cam, closes the air valve to shut off suction to the pick and lift

arms

66, 67. The valve is in communication with the

shafts

60, 61 of the arms thru piping 110, and this piping may have flexible sections contiguous with the shafts to allow rotation thereof. The valve is, also, provided with a portion for connection to a vacuum pump which pump is not shown.

The funnel cam 85 has its follower arm 111. A fun nel follower link 112 connects the follower arm 111 to the lower end of a funnel lever 113. The upper end of the funnel lever is curved outward of the frame and has secured thereto one end of a funnel operating bar 114 which is parallel and adjacent to the funnel Y- crank arm stems 48 on the open side of the frame for movement of such stems 48 to collapse and open the funnel skirts when they are in position to receive the bags.

The end of the operating bar 114 away from the funnel lever 113 is secured to bar arm 116. Both the lever 113 and the arm 116 are secured at their pivot points to a sleeve 117 that is bearinged in brackets 118 secured to the frame 11.

The bag pick cam 86 has its follower arm 121 connected by a link 122 to a crank 123 secured to the pick shaft 60 near its open end for operation of the pick arm 66.

In a similar manner, the bag open cam 87 has its follower arm 124 connected by a link 126 to a crank 127 secured to the bag open shaft 61 near its open end for operation of the bag open arm 67.

The lift cam 88 has its follower arm 128 connected by a link 129 to one end of a bell crank 131 which is secured to the left end of a shaft 132 which is below and extends between the lift arms 56. The shaft is bearinged in brackets 133 secured to parts of the frame 11.

The right end of the shaft has secured thereto an arm 134 that has its free end connected to the adjacent lift arm 56 by a link 135. A similar link 136 connects the free end of the bell crank 131 to its adjacent lift arm 56. Thus thebell crank can moveboth lift arms simultaneously and in parallelism.

The weight of the lift arms and the parts carried thereby are sufiicient to hold the lift follower 128 against the lift cam 88. Suitable springs are provided for the other mechanisms to hold their followers against their respective cams, but these springs have not been shown.

The lower end of the. drive drum shaft 21 is connected to gears in'a gear box 137 as the input end thereof. The Q ar 9 t i s F r an a. areal-t8 W 9 i on its other end the fill conveyor drive pulley 76. The value of the gears in the gear box 136 is such that the fill conveyor 74 will travel at the same speed as the

chains

14, 15. The conveyor will travel in time with the chains as the primary drive of both is from the drive drum 12.

It is believed that the operation of the machine has been clearly set forth in connection with the description of the cam curves of Figure and is not here repeated.

Having thus described the construction and operation of a machine embodying the present invention, I claim:

1. A bag opener, comprising: a pair of spaced apart drums, an endless chain around and between said drums, secured to and evenly spaced along said chain a plurality of funnels, one of said drums being a drive drum having a circumference equal to a whole multiple of such space, and a plurality of drive pins angular'ly spaced about the axis of said drum on equal arcs, the number of said pins being a whole factor of such multiple.

2. The combination of claim 1 in which the spacing of said funnels along said chain is an even multiple of the length of the links of said chain.

3. The combination of claim 1 in which said funnels are collapsible.

4. A bag opener, comprising: a frame, supported by said frame a pair of drums spaced apart coplanar horizontally, an endless chain around and between said drums in ovate form to provide two straight runs of said chain, secured to and evenly spaced along said chain a plurality of funnels, one of said drums being a drive drum having a circumference equal to a whole multiple of such space, and a plurality of drive pin equiangularly spaced about the axis of said drive drum on equal radii, the number of such pins being a whole factorof such multiple; along and below one of such runs a bag pickup arm, a bag opener arm, each of said arms having a bag engaging portion, and means for mounting said arms for pivotal movement so that each arm may have movement about its own axis spaced from the other axis, so that each portion is radially spaced from its axis, and so that said arms may have movement between a position in which said portions are contiguous, a position in which said portions are disengaged and unopposed, and a position in which said portions are opposed and spaced; in said means a pivot block for said arms; and out of said means a link for raising and lowering said block so that when said portions are so spaced one of said funnels will have a part thereof in such space, and a drive for said drums, chain, link, and for positioning said arms.

5. A bagpicker and opener, comprising: a picker for contacting and securing thereto the front side of a folded flat bag; an opener for contacting and securing thereto the rear side of such folded flat bag; and means for moving only coplanarly said picker and opener so that'said picker contacts and secures thereto the front side of such bag and thereafter has a path of movement in which such bag trails said picker in the direction of such movement, and for moving said opener after said picker so that said opener overtakes said picker and such bag to contact and secure to the back side thereof.

6. The combination of claim 5 in which said means moves said opener so that its movement has a component transverse such path prior to said opener contacting such bag.

7. The combination of claim 5 in which said means moves said picker and opener apart to open such bag after they are both secured to such bag.

8. The combination of claim 7 in which said means moves said picker and opener, while secured to and carrying such bag in open condition, transversely of such path.

9. The combination of claim 5 in which said means moves said opener so that its movement has a component transverse such path .prior to said opener contacting such bag, "and "moves "said "picker and "opener a art to 8 open such bag after they are both secured thereto, and in which additional means is provided for moving said picker and opener,'while secured to and carrying such bag in open condition, transversely of such path.

10. The process of picking a fiat folded bag from a stack of such bags and of opening such bag, such bags having front and rear sides, comprising: first, engaging the front outside of the bag and by such engagement moving the bag from the stack and along a path in a plane so that the rear side thereof trails the front side in the direction of such movement, second, engaging the rear outside of the bag and by such engagement movingin such plane therear side from the front side to open the bag, and, third, while maintaining the bag open by such engagement, moving the bag in such plane in a direction transverse such path.

11. Adding to claim l0, fourth, engaging the inside of the bag and further opening it by such engagement.

12. Adding to claim 11, fifth, placing such bag under tension by such inside engagement.

13. A bag picker and opener, comprising: a bag stack platform for holding a stack of bags in closed flat form and in side-by-side stacked relationship with the top bag thereof having a front side away from the rest of the bags of such stack and a back side toward the bags of such stack; a bag pickup arm; a bag opener arm; a bag engaging and securing portion carried by each of said arms; a pivot block mounting said arms for pivotal movement so that each arm has movement about its own axi spaced from and parallel to the axis of the other arm, and so that each portion is radially spaced from said block; and means for moving said arms and their portions and said block so that said pickup portion contacts and secures thereto the front side of such top bag and thereafter has a path of movement in which such bag trails said pickup portion in the direction of such movement, so that said opener portion moves along such path in such direction so that said opener portion overtakes such bag to contact and secure to the back side thereof, so that said portions move apart to open such bag after they are both secured thereto, and so that said block, arms, and portions, while carrying such bag in open condition, move transversely of such path.

14. A bag picker and opener, comprising: a picker for contacting and securing thereto'the front side of a folded flat bag; an opener for contacting and securing thereto the rear side of such folded flat bag; an arm for said picker; an arm for said opener; a pivot for each of said arms, said pivots being parallel and spaced apart; and means for moving said picker and opener and their arms about their respective pivots so that said picker contacts and secures thereto the front side of such bag and thereafter has a path of movement in which such bag trails said picker in the direction of such movement, and for moving said opener after said picker so that said opener overtakes said picker and such bag to contact and secure to the back side thereof.

15. The combination of claim 14 in which said means moves said arms so that said picker and opener move apart to open such bag after they are both secured to such bag.

16. The combination of claim 15 in which additional means is provided for moving said arms transversely of such path while said picker and opener are secured to and carrying such be gin open condition.

17. A bag picker and opener, comprising: a picker for contacting and securing thereto the front side of a folded flat bag; an opener for contacting and securing thereto the rear side of such folded flat bag; and means for moving said picker and opener so that said picker contacts and secures thereto the front side of such bag and thereafter has a path of movement in which such bag trails said picker in the direction of such movement, for moving said opener after said picker so that said opener overtakes said pickerand"such'bag'to'contact"andsecure"to the'back side thereof, and for moving said picker and opener apart to open such bag after they are both secured to such bag. V

18. The combination of claim 17 in which additional means is provided for moving said picker and opener, while secured to and carrying such bag in open condition, transversely of such path.

References Cited in the file of this patent UNITED STATES PATENTS 1,909,319 Taylor May 16, 1933