Bag Wicketter

Abstract

A machine for assembling plastic bags on wickets as a step in the production of packets of plastic bags. A plastic bag having a flap provided with mounting holes is fed vertically downward between the suction transfer arms of a rotating double set of transfer arms which carry the bag to wickets mounted in register with the flap holes. By feeding the bags vertically downward between the suction transfer arms the problems of transfer caused by static charges and glossy surface are minimized.

Description

This invention relates to a machine adapted to assemble plastic bags on wickets as a step in the reproduction of bag packets.

Bag packets in which the individual bags are retained in place by fasteners inserted through holes in the bag flap are in common use. These packets have the advantage that successive bags can be filled and withdrawn from the packet one by one, thus allowing for the bags to be filled more quickly with fewer manual operations. This type of bag package is described in U.S. Pat. No. 3,100,569 issued on Aug. 13, 1963. The fasteners by which the bags are held in place are the wickets.

The production of such bag packets requires that bags with pierced flaps be mounted on the wickets. This may be carried out manually but a mechanical means for mounting the bags is clearly of advantage. It is also desirable that such a mounting device be integrated with the machine that fabricates the bags. However, the transfer at high rates of plastic bags from the bagmaking machine to the wicket gives rise to problems in handling light film material having a glossy surface. The plastic material also tends to develop a static charge which interferes with its transport.

It has been found that plastic bags having pierced flaps can be transferred from the output of a bagmaking machine and mounted on wickets to form bag packets if the output from the bag making machine issues vertically downward free from guiding means into the sweep area of a set of suction transfer arms so that the bag becomes affixed thereto by suction means with its bag flap holes in register with the posts of an adjacently mounted wicket, the suction transfer arms carrying the bag to the wicket and mounting it thereon. The free vertical downward delivery of the bags to the suction transfer arms permits reproducible loading of the transfer arms through avoidance of irregular motion of the bag frequently associated with its separation from a horizontal feed mechanism such as a moving belt.

It is thus a primary object of this invention to provide a machine for assembling the output of a bagmaking machine into bag packets retained by wickets. Additional objects will appear hereinafter.

The bag packet assembly machine of this invention comprises:

1. means for providing a plastic bag having a flap pierced with at least two holes,

2. movable suction transfer arms adapted to sweep through the area located beneath the output position of the bag-providing means,

3. means for delivering the plastic bag vertically downward into the sweep area of the transfer arms so that the bag becomes affixed thereto by suction, and

4. wicket support means located adjacent to the transfer arms with the posts of the wicket in register with the holes of the bag flap carried by the transfer arms, so that the bag is transferred from the transfer arms to the wicket.

The invention is illustrated in the accompanying drawings wherein:

FIG. 1 is a diagrammatic side elevation of the bag-assembling machine operating at the output of a bagmaking machine;

FIG. 2 is a front elevation of a portion of the suction transfer arm assembly, and

FIG. 3 is a front elevation, partly in section, of a portion of FIG. 2.

In FIG. 1 a plastic bag 1 is shown being delivered from the seal head roll 2 and sealer bar 3 of bagmaking machine. This bag drops vertically downward between two suction transfer arms 4 which are turning in coordination with the main drive shaft 5 of the bagmaking machine. Drive shaft 5 operates seal head roll 2 and sealer bar 3 in intermittent manner so as to advance the web of film, stop the film motion, seal and sever the film and again advance the film in a repetitive cycle. During this cycle the sealer bar 3 is pressed against the film and retracted through the action of linkage 6 and 7 actuated by cam 8 carried by the main drive shaft. Also attached to the main drive shaft is arm 9 to which is coupled rack bar 10. Rack bar 10 engages pinion 11 which is connected to sprocket 12 by means of a unidirectional clutch. Sprocket 12 is connected by chain drive 13 to seal head roll 2. Owing to the action of the unidirectional clutch connecting pinion 11 to sprocket 12 the seal head roll is driven unidirectionally during each alternate half revolution of drive shaft 5. The relative positions of cam 5 and arm 9 are such that seal head roll 2 is motionless during the time that the sealer bar 3 is pressed against the film. Nip rolls 14 are connected by a chain and sprocket drive to seal head roll 2 and turn in synchronism with it.

The suction transfer arms are carried radically by shafts 15 to which are attached sprockets 16. Sprockets 16 are driven through a step down chain drive 17 connected to main drive shaft 5. Suction transfer arm shaft 15 turns at one-sixteenth the speed of main drive shaft 5 so that successive suction transfer arms are brought into position in synchronization with the delivery of each bag from the bagmaking machine.

Main drive shaft 5 is driven by motor 18 through drive 19.

The coordination between the operation of the suction transfer arms and the sealer bar assembly is such that the bag issuing from the bagmaking machine is grasped by the suction arms with the wicket openings of the bag in register with wicket posts 20. Wicket posts 20 are carried by a conveyor belt system 21 whose movement is controlled so that wicket positions are changed when a predetermined number of bags are assembled on an individual wicket.

Suction to actuate the suction transfer arms is provided by a fan 22 driven by motor 23 and connected through tube 24 to suction transfer arm support tube 25.

In FIGS. 2 and 3 details of construction of the suction transfer arms are given. The arms 4 are formed from square section tubing closed at the outer end. The arms 4 are carried by distributor wheel 26. Distributor wheel 26 is mounted on shaft 15 which is rotatable in bushing 27. Shaft 15 also carries drive sprocket 16. Distributor wheel 26 fits into air guide 28 which is attached to the extremity of bushing 27. Nut 29 engages a threaded portion of bushing 27 and serves to hold air guide 28 in contact with square section support tube 25. Support tube 25 is closed at its upper end while its lower end is connected to vacuum tube 24. Distributor wheel 26 has 16 internal L-shaped channels 30 passing from the interior of suction arms 4 to air guide 28. Air guide 28 has an arc-shaped channel 31 corresponding to a 90.degree. rotation of channel 30, and opening into support tube 25. The function of air guide 28 thus is to connect each suction transfer arm to a source of vacuum during 90.degree. of its rotation. The suction transfer arms are provided with openings on their leading sides. These are of two types, slit 32 on the set of suction transfer arms adjacent to the bag flap and a series of circular openings 33 on the suction transfer arms adjacent to the bag bottom. The slit is used to hold the bag flap since it helps in obtaining exact reproducibility of positioning of the flap as is necessary in order to keep wicket openings 34 in register with wicket posts 20. The circular suction openings are used to hold the bag bottom where reproducibility of position is not critical.

The bag packet assembling machine of this invention can be employed in coordination with known bagmaking machines. Such machines form plastic bags from lengths of two ply folded plastic film by transverse sealing and cutting. The flaps of the bags are provided by using folded film having one of the panels wider than the others disclosed in Canadian Pat. application Ser. No. 993,861 filed June 23, 1967 (U.S. Pat application Ser. No. 626,296 filed Mar. 27, 1967). An attachment to the bagmaking machine forms the holes 34 for mounting bags on the wickets. The bagmaking machine advances the length of film intermittently in increments equivalent to one bag width, the sealing and cutting operations being carried out during stationary periods of the film.

The bagmaking machine of this invention provides a means for mechanically assembling the output of a bagmaking machine into wicketed bag packets.

Claims

What we claim is:

1. A bag packet assembling machine adapted to assemble bags on wickets, said wickets having at least two wicket posts, comprising:

1. means for providing a plastic bag having a flap pierced by at least two holes,

2. movable suction transfer arms provided with openings on their leading sides adapted to hold a plastic bag by suction, said arms being adapted to sweep through the area located directly beneath the output position of the bag-providing means,

3. means for connecting the openings of the suction transfer arms to a source of suction,

4. means for delivering the plastic bag vertically downward free from guiding means into the sweep area of the transfer arms so that the bag becomes affixed thereto by suction, and

5. wicket support means located adjacent to the transfer arms and adapted to maintain the posts of the wicket in register with the holes of the flap of the bag carried by the transfer arms, so that the bag is transferred from the transfer arms to the wicket.

2. A bag packet assembling machine as claimed in claim 1 wherein the means for providing the plastic bag is a bagmaking machine.

3. A bag packet assembling machine as claimed in claim 1 wherein the suction transfer arms sweep through a circular path.

4. A bag packet assembling machine as claimed in claim 1 wherein suction is applied to the suction transfer arms only during the period of transfer of the bag to the wicket.

5. A bag packet assembling machine as claimed in claim 1 wherein the suction transfer arms are fitted with slit openings for engaging the plastic bag.

6. A bag packet assembling machine as claimed in claim 1 wherein the suction transfer arms are fitted with circular openings for engaging the plastic bag.

7. A bag packet assembling machine as claimed in claim 1 wherein the wicket support means is adapted to replace wickets after a predetermined number of bags have been assembled thereon.