US3680725A

US3680725A - Bag slitting machines

Info

Publication number: US3680725A
Application number: US21390A
Authority: US
Inventors: Barrie Armstrong Poulton
Original assignee: Simon Handling Engineers Ltd
Current assignee: Simon Handling Engineers Ltd
Priority date: 1969-04-02
Filing date: 1970-03-20
Publication date: 1972-08-01
Anticipated expiration: 1989-08-01
Also published as: DE2015485B2; BE748077A; DK121698B; AU1301770A; FR2042837A5; SE355553B; NL7004532A; DE2015485A1; GB1290337A; JPS5113076B1; ZA701981B

Abstract

A bag slitting machine comprising spaced support means adapted to engage opposite ends of a bag to support same over a discharge opening located between said spaced support means, slitting blade means arranged to traverse said discharge opening and adapted to slit the underside of a bag when so supported, and means for alternately raising and moving towards one another and lowering and moving away from one another said support means a number of times to promote the flow of the contents of said bag through said discharge opening.

Description

[ 51 Aug. 1, 1972 United States Patent Poulton [5 1 BAG SLITTING MACHINES Primary Examiner-Gerald M. Forlenza Assistant Examiner-Lawrence J. Oresky Att0rney--Norris & Bateman [72] Inventor: Barrie Armstrong Poulton,

Stockport, England [73] Assignee: Simon Handling Engineers Limited [57] ABSTRACT A bag slitting machine comprising spaced support means adapted to engage opposite ends of a bag to [22] Filed: March 20, 1970 [21] Appl. No.: 21,390

support same over a discharge opening located between said spaced support means, slitting blade means arranged to traverse said discharge opening and adapted to slit the underside of a bag when so sup- [30] Foreign Application Priority Data April 2, 1969 Great Britain.............

ported, and means for alternately raising and moving towards one another and lowering and moving away from one another said support means a number of times to promote the flow. of the contents of said bag through said discharge opening.

80 00 5 W6 2 MB BM 4 1 .m Lm G St Um 1L 21 55 [58] Field of References Cited UNITED STATES PATENTS 3,482,718 12/1969 Moriarty............'........

8 Claims, 2 Drawing figures BAG SLITTING MACHINES This invention concerns bag slitting machines for opening bags to enable the contents thereof to be empne It has been proposed for a bag opening and emptying machine to provide a slit in the bag and to promote the flow of material from the bag by vibration. Experiments have shown that this method is not satisfactory for certain materials which are difficult to handle and that a much more positive method of promoting flow of material from the bag is required.

According to the present invention, a bag slitting machine comprises spaced support means adapted to engage opposite ends of a bag to support same over a discharge opening located between said spaced support means, slitting blade means arranged to traverse said discharge opening and adapted to slit the underside of a bag when so supported, and means for alternately raising and moving towards one another and lowering and moving away from one another said spaced support means a number of times to promote the flow of the contents of said bag through said discharge opening.

The invention will be further apparent from the following description with reference to the figures of the accompanying drawing, which show, by way of example only, one form of bag slitting machine embodying the invention.

Of the drawing:

F IG. 1 shows a partly cut-away perspective view of the machine from the front and FIG. 2 shows a plan view of part of the mechanism of the machine of FIG. 1.

Referring now to the drawing, it will be seen that the machine includes spaced support plates and 11, which in their normal position (FIG. 1) are inclined towards one another to define a bed of shallow V- shaped configuration. Between and below the

plates

10 and 11 is a hopper 12 having a discharge opening 13 at its lower extremity for delivery of material from bags emptied by the machine. The

plates

10 and 11 are respectively carried by pairs of

arms

14 and 15 which are pivotally connected with fixed frame members at their lower ends. The arms 14 may be raised and lowered by a double-acting pneumatic cylinder 16 and the arms 15 are connected for movement with the arms 14 by intermeshing

equal gear wheels

17 and 18 secured to the

arms

14 and 15 respectively.

Between the plates 10 and l l and over the hopper 12 are upwardly projecting

knife blades

19 and 20 carried on pivoted

arms

21 and 22 which may be moved by double-acting

pneumatic cylinders

23 and 24.

In use, a bag which is to be opened and emptied is placed on a loading table 25. The weight of the bag operates a micro-switch 26 which starts the machine cycle. The table is first pivoted forwardly under the action of a pneumatic cylinder 27 to throw the bag onto the bed of the machine where it is impaled on the

knife blades

19 and 20 and on upwardly projecting spikes 28 provided on the

support plates

10 and 11. The

cylinders

23 and 24 are then operated to cause the

knife blades

19 and 20 to separate generally transversely of the bag to slit its underside. A stirrup member 29 is then swung under the action of a pneumatic cylinder 30 in clockwise direction so that its central web is impacted with the upper surface of the bag over the slit in its underside before being returned in counterclockwise direction toits initial position. This operation causes a weakening of the bag in its central region and causes material in the vicinity of the slit to flow from the bag and fall into the hopper 12, thereby facilitating subsequent operations as will now be described.

The cylinder 16 is reciprocated a predetermined number of times to cause the

plates

10 and 11 alternately to move upwardly andtowards one another and downwardly and away from one another a like number of times. The ends of the bag which are supported on the two plates thus move in a similar fashion, the bag thus being alternately folded and unfolded about its center. This operation promotes the flow of the entire contents of the bag through the slit in its underside and into the hopper 12.

When the bag has emptied a stirrup member 31 which normally lies in a horizontal plane over the hopper is swung upwardly under the action of a pneumatic cylinder 32 to engage the empty bag and throw it clear of the machine.

Finally the member 31 and

knife blades

19 and 20 are returned to their initial positions in readiness for the next machine cycle.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible without departing from the scope thereof.

. For example, with certain materials which are highly flowable it may only be necessary to raise and lower the support plates once in each machine cycle.

What is claimed is:

1. A bag slitting machine comprising spaced support means having upwardly directed spikes and adapted to engage opposite ends of a bag to support said bag over a discharge opening located between said spaced support means, means mounting said support means for rotational movement about axes lying below and inwardly of same, slitting blade means adapted to slit the underside of a bag when so supported, said slitting blade means comprising two upwardly projecting blades which in one position are disposed adjacent one another centrally over the discharge opening and which impale a bag positioned on the machine and which separate from one another for the purpose of slitting the underside of the bag, and means for alternately raising and moving towards one another and lowering and moving away from one another said support means a plurality of times to promote the flow of the contents of said bag through said discharge opening, said support means being inclined towards one another when at their lowermost positions to define a bed of shallow V- shaped configuration for supporting a bag.

2. A bag slitting machine according to claim 1 including means adapted to deliver an impact to the upper surface of the bag after it has been slit and before said support means are raised and lowered.

3. A bag slitting machine according to claim 2 including a stirrup member surrounding the field of movement of the slitting blade means and adapted to be swung from a generally horizontal position upwardly for the purposes of discharging a bag which has been emptied.

4. A bag slitting machine according to claim 3 including a pivotally mounted feed table adapted to receive a bag to be opened and emptied and to tip same onto the support members of the machine.

5. A bag slitting machine comprising spaced support means adapted to engage opposite ends of a bag to support same over a discharge opening located between said spaced support means, slitting blade means arranged to traverse said discharge opening and adapted to slit the underside of a bag when so supported, and means for alternately raising and moving towards one another and lowering and moving away from one another said support means a number of times to promote the flow of the contents of said bag through said discharge opening, said slitting blade means comprising two upwardly projecting blades which in one position are disposed adjacent one another centrally over the discharge opening and which impale a bag positioned on the machine and which separate from one another for the purpose of slitting the underside of said spaced support means, slitting blade means arranged to traverse said discharge opening and adapted to slit the underside of a bag when so supported, means for alternately raising and moving towards one another and lowering and moving away from one another said support means a number of times to promote the flow of the contents of said bag through said discharge opening, and means adapted to deliver an impact to the upper surface of the bag after it has been slit and before said support means are raised and lowered.

7. A bag opening and emptying machine comprising spaced members for supporting opposite ends of a bag, bag slitting means disposed between said members, means for actuating said bag slitting means for opening the underside of a bag on said support members, means for repeatedly rocking said members about substantially parallel axes for correspondingly repeatedly folding and unfolding said bag while it is discharging through its slitted opening, and means for sequentially impacting the upper side of said bag after the underside has been slitted.

8. The bag opening and emptying machine defined in claim 7, wherein said members are cyclically alternately moved upwardly and towards one another and downwardly and away from one another.

Claims

1. A bag slitting machine comprising spaced support means having upwardly directed spikes and adapted to engage opposite ends of a bag to support said bag over a discharge opening located between said spaced support means, means mounting said support means for rotational movement about axes lying below and inwardly of same, slitting blade means adapted to slit the underside of a bag when so supported, said slitting blade means comprising two upwardly projecting blades which in one position are disposed adjacent one another centrally over the discharge opening and which impale a bag positioned on the machine and which separate from one another for the purpose of slitting the underside of the bag, and means for alternately raising and moving towards one another and lowering and moving away from one another said support means a plurality of times to promote the flow of the contents of said bag through said discharge opening, said support means being inclined towards one another when at their lowermost positions to define a bed of shallow V-shaped configuration for supporting a bag.

5. A bag slitting machine comprising spaced support means adapted to engage opposite ends of a bag to support same over a discharge opening located between said spaced support means, slitting blade means arranged to traverse said discharge opening and adapted to slit the underside of a bag when so supported, and means for alternately raising and moving towards one another and lowering and moving away from one another said support means a number of times to promote the flow of the contentS of said bag through said discharge opening, said slitting blade means comprising two upwardly projecting blades which in one position are disposed adjacent one another centrally over the discharge opening and which impale a bag positioned on the machine and which separate from one another for the purpose of slitting the underside of the bag.

6. A bag slitting machine comprising spaced support means adapted to engage opposite ends of a bag to support same over a discharge opening located between said spaced support means, slitting blade means arranged to traverse said discharge opening and adapted to slit the underside of a bag when so supported, means for alternately raising and moving towards one another and lowering and moving away from one another said support means a number of times to promote the flow of the contents of said bag through said discharge opening, and means adapted to deliver an impact to the upper surface of the bag after it has been slit and before said support means are raised and lowered.