US3421286A

US3421286A - Automatic bagging machines

Info

Publication number: US3421286A
Application number: US570584A
Authority: US
Inventors: Edward J Chambless Jr
Original assignee: ST Regis Paper Co
Current assignee: ST Regis Paper Co; Standard Chartered USA
Priority date: 1966-08-05
Filing date: 1966-08-05
Publication date: 1969-01-14
Anticipated expiration: 1986-01-14

Description

1969 E. J. CHAMBLESS, JR 3,421,286

AUTOMATIC BAGGING MACHINES Sheet Filed Aug. 5, 1966 &

1969 E. J. CHAMBLESS, JR

AUTOMATIC BAGGING MACHINES Sheet 2 of 3 Filed Aug.

1969 E. J. cHAMsLEss, JR 3,421,286

AUTOMAT I C BAGG ING MACHINES Filed Aug. 5, 1966 Sheet 3 of 5 United States Patent 3,421,286 AUTOMATIC BAGGING MACHINES Edward J. Chambless, Jr., Austin, Tex., assignor to St.

Regis Paper Company, New York, N.Y., a corporation of New York Filed Aug. 5, 1966, Ser. No. 570,584

US. Cl. 53-190 Int. Cl. B65!) 5/00; B65b 9/00 Claims ABSTRACT OF THE DISCLOSURE This invention relates to automatic bagging machines and more particularly to machines of that class adapted for applying bags such as of polyethylene or other plastic film material to loaves of bread, other comestibles or objects.

The invention involves certain improvements making it possible to use such machines for applying plastic film bags, which may vary somewhat from their intended dimensions or have other varying characteristics, and to do so while avoiding disruption of the bag and consequent failure of the machine to operate reliably and rapidly.

By way of example, the invention will be herein described and illustrated as applied to a so-called Mark 50 automatic bread packaging machine, now well known on the market and as described and illustrated in the drawings of a manual published in March 1965 for that machine by Commodity Packaging Co., Inc. of Yakima, Wash. (now Bakery Machinery Division, American Machine & Foundry Co., 2115 W. Laburnum Avenue, Richmond, Va. 23227). Features of the invention may be applied to other machines of that class adapted for like or similar purposes.

In machines of that type, spaced-apart scoop elements are reciprocatably mounted to travel endwise past an object such as a loaf of bread and enter into an open mouth of a plastic film bag and become spread apart somewhat to grip the bag internally, the scoop elements being then retracted for drawing the bag into the desired position surrounding the loaf. Such plastic film bags, although intended to be manufactured to predetermined sizes, nevertheless are necessarily produced very rapidly and inexpensively with the film being heat-sealed along one or usually two longitudinal lines. Under these circumstances the circumference of the bag, although intended to be of a certain predetermined size, may vary somewhat from bag to bag due to variations in the character and position of the lines of heat-sealing or due to variations in the stretchability of the film material under varying conditions. As a result the scoop elements which enter the bag mouth and shape same to receive the loaf, may from bag to bag tend to exert different amounts of pressure against the interior surfaces of the bag walls. Thus even though the operating supports for the two scoop elements may be carefully adjusted so that they will expand in the bag to accurately predetermined spacedapart positions for accommodating a predetermined size of bag, yet, because of the variations in the successive bags, the scoop elements may in some cases overstretch "ice the mouths of the bags, or in other cases fit in place too loosely, and cause disruption of the film of the bag or allow it to slip out of proper control. Even if this only occurs infrequently, it will be necessary to stop the machine for a considerable period to clean away disrupted bags and possibly mangled bread loaves or other commodities and also this will interrupt the regular normal automated flow through the plant of the commodity being made and bagged.

In accordance with the present invention this problem has been surprisingly well overcome by providing in the linkage which operates one of the scoop elements, for example the upper scoop element, means in the form of an air-operated cylinder and piston device for so applying pressure to the linkage as to urge such upper scoop element with a uniform pressure against the upper inner wall of the mouth of the bag. That is, the pressure which the scoop element is thus caused to exert will be uniform, even though the upward movement of the scoop element in coming into engagement within the inner wall of the mouth of the bag, will be stopped at varying levels depending on inaccuracies in the dimensions or character of successive bags.

It may be noted that efforts have been made so to arrange the linkage for operating the scoop element that the latter will be pressed upwardly essentially by spring means, but such means has not proven satisfactory, possibly because such machines operate with great rapidity and any such spring means may not only inherently vary its pressure because of varying its tension, but also because of vibrating and oscillating efiects which are avoided with the air pressure operated cylinder and piston means in accordance with the present invention.

Various further and more specific objects, features and advantages of the invention will appear from the description given below, taken in connection with the accompanying drawings, illustrating by way of example a prefer-red form of the invention.

In the drawings:

FIG. 1 is a side elevational view of the machine of the particular type above referred to and embodying the improvements of the present invention;

FIG. 2 is an enlarged elevational view of the parts of such a machine which are more particularly concerned with the improvements of the present invention;

FIG. 3 is a diagram illustrating the air-operated cylinder, piston and associated air pressure connections used in accordance with a preferred example of the invention; and

FIG. 4 is a vertical sectional view of a typical airoperated cylinder and piston means adapted for use for the present invention.

Referring in further detail to FIG. 1, the essential parts of the above-mentioned type of machine will first be referred to. Suitable conveyor means, although not shown in FIG. 1, may extend generally horizontally from the position of the viewer transversely across the top of the machine as shown in FIG. 1, to convey loaves of bread or other objects to a packaging station at the position indicated at 19. Equipment indicated generally at 11, of any suitable known type, may be provided for holding a stack of the initially fiat plastic film bags which are brought into a position so that as by use of air jets, the mouth portion of each successive bag is blown to an open condition ready to receive spaced-apart upper and lower scoop elements as at 12, 13 which are reciprocated endwise past the loaf of bread, for example, located at It to enter into the open mouth of the plastic bag which has been made ready to receive same by the equipment at 11. Meanwhile a so-called blockade arrangement indicated generally at 14 is operated to thrust a blocking element 15 into contact with the end of the loaf to retain same against endwise movement at the packaging station while the

scoop elements

12 and 13 have entered into and engaged within the mouth of the plastic bag. Then the scoop elements are retracted to pull the bag over the loaf at station 10, while the loaf is prevented from moving by the blockade device until the plastic bag is drawn into position fully to contain the loaf, and the scoop elements are retracted to the position shown in FIG. 1.

The scoop elements are carried by a shuttle element indicated at 16 which reciprocates along a shaft 16a to move the scoop elements to and fro in the process of their reaching for a plastic film bag and drawing same over the loaf. The shuttle element 16, as better shown in FIG. 2, may be operated by a link 17 pivotally connected at its upper end thereto about an axis 18. The other end of this link is pivotally connected about an axis 19 to a lever 20, which in turn is pivotally mounted about an axis as at 21 at the base of the machine. The lever is swung back and forth as by link means 22 which is of adjustable length, this link being pivotally connected at 23 to the lever 20 and at its other end at 24 to a member 25 which may incidentally be a cam member rotated about an axis 26 for operating the above-mentioned blockade arrangement.

During the reciprocating movement of the

scoop elements

12 and 13, the vertical spacing therebetween is alternately increased and decreased by linkage means so that the scoop elements enter the bag month while they are colser together, and will then expand apart or become more separated to engage the interior surfaces within the mouth of the bag and continue such engagement until the bag is pulled over the leaf of bread, whereupon their vertical spacing may be reduced again. With machines of the type above referred to, thisis accomplished by a cam 27 rotatable on axis 26 and engaging a cam follower 28 mounted on an upstanding lever 29 which is pivotally mounted at 29a.

Lever 29 is pivotally connected at 30 to a link member generally indicated at 31, the other end of which is pivotally connected at 32 to a bell crank 33 having its central pivot at 21 and having an arm 33a pivotally connected at 34 to a link 35. A spring 32a normally pulls against link means 31 and thereby acts to maintain cam follower 28 in contact with cam 27. The link is pivotally connected at 35a to a bell crank 36 pivotally mounted on an axis at 19. Another arm 36a of this bell crank is pivotally connected at 37 to a link 38, the latter in turn being pivotally connected at 39 to another bell crank 40 having its central pivot at 18 and having another arm 40a which is slotted to provide an adjustable pivotal connection 41 to a further link 42, the latter in turn being pivotally connected at 43 to a rocker arm 44. The rocker arm 44 is pivotally mounted at 45 and carries at its lefthand end 44a the upper scoop element 12.

It will be apparent that the linkage by which the upper scoop element is tilted by rotation of cam 27, is such that the tilting movement can be imparted during reciprocation of the shuttle member 16 without interfering with the reciprocating movements of the scoop elements.

The parts of the machine as thus far described, with the exception of the construction of the link means 31 as hereinafter explained, may all be constructed and operated in accordance with the known machines of the above-mentioned type. Of course, the various parts are power driven by suitable mechanical connections as from a motor 46 (FIG. 1) so that each portion of the machine will operate in proper synchronous relation to the other portions and the accompanying conveying means.

Referring further to the link 31, in former examples of this machine, this link was simply adjustable in length 'by reason of its threaded ends, and upon such adjustment and possible adjustment of various others of the links, the scoop element 12 would be tilted up and down as required during each stroke and as above explained. Once the linkages were thus adjusted, although the scoop 12 and its rocker arm support 44a might have some resiliency, yet the limits of the up and down movements thereof would be substantially fixed and not variable without stopping the machine and readjusting the linkage or other parts. However, for the above-explained reasons, the desirable upward swinging movement of this scoop element may vary from bag to bag, so that it should stop at the level of one or another of the dotted lines, as indicated at 48 (see upper left corner of FIG. 2), and in doing so, apply substantially a predetermined upward pressure against the inner surface of the mouths of bags even if of inaccurately-formed dimensions. To make this possible in accordance with the present invention, the link 31 has interposed therein the above-mentioned cylinder and piston means, indicated at 49 with the piston operated by air pressure in a direction tending to pull against the bell crank arm 35. By following through the linkage shown in FIG. 2, it will be apparent that this pulling effect acts to apply an upward tilting pressure to the scoop rocker arm 44a, but at no time a greater pressure than that corresponding to the air pressure in the device 49. Of course, while compressed air Will usually be used to operate the device 49, other gases should be considered as equivalent for the purpose.

One example of the device 49 suitable for use with the invention is further illustrated in the sectional view of FIG. 4, wherein the cylinder is indicated at 50, a piston at 51 and a piston rod at 52 connected as shown in FIG. 2 to the pivot point 32 on the bell crank arm 33.

The device 49 may, with a machine of the type abov referred to, have an internal cylinder diameter for example in the neighborhood of inch and the air pressure therein may be maintained in the range of 50 to 70 pounds per square inch when the machine is operating to apply common types of plastic film bags to bread. However, the pressure may vary according to the strength and size of the bag being used. The piston may have a maximum stroke of about one inch.

As shown in FIG. 3, the left-hand end of the device 49 is coupled by suitable means at 53 to the remainder of the link means 31 and the right hand end of the device 49 may have a suitable stufiing box or the like 54 through which the rod 52, shown in FIG. 4, may slide and extend to the pivotal connection 32. As further indicated in FIG. 3, the air under pressure may be brought into the right hand end of the device 49 through a connection 55 of a conduit running to a pressure regulator 56 and thence to a suitable filter 57 connected as by a quick-detachable connection if desired at 58 and to a source of .air supply. A suitable air-operated electrical switch may be provided at 59 to open the electrical circuit of the motor drive for the machine and to thus prevent the operation of the bagging machine when the supply air pressure drops below an acceptable minimum value such as, for example, 40

pounds per square inch. The left hand end of device 49 (as shown in FIG. 4) may have a vent 60 open to the atmosphere. The overall length of the link means 31 may, of course, be adjusted as heretofore by suitable screwthreaded connection means at 61. Ordinarily it should be adjusted to such length that the piston 51 will normally be near the left hand end of the cylinder as shown in FIG. 4. And when the scoop member 12 in engaging the inside surface of the mouth of the bag, meets with resistance, it will apply a predetermined pressure depending upon the pressure in the cylinder 50, and thereupon stop the upward movement of the scoop without disrupting the bag and yet insuring adequate and predetermined pressure against the bag surface.

Although a certain particular embodiment of the invention is herein disclosed for purposes of explanation, further modifications thereof, after study of this specification, will be apparent to those skilled in the art to which the invention pertains. Reference should accordingly be had to the appended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. In a machine for automatically applying bags of sheet material to objects to be bagged therein, the machine having spaced-apart scoop-like elements, means for reciprocably mounting same to travel past the object to be bagged and to enter into the open mouth of a bag, mechanical linkage mechanism being provided to then spread apart said elements somewhat further and into engagement with the interior surfaces of the mouth of the bag, said reciprocable mounting means then acting to retract said elements with the bag thereon and to pull the same into surrounding relationship to the object being bagged, the improvement which comprises providing in said mechanism an air pressure operated means operable subsequent to engagement between said scoop-like elements and the interior surfaces of the mouth of the bag for applying a predetermined force acting through said mechanism to cause said scoop means to exert a predetermined spreading pressure against the interior surfaces of the mouths of the bags notwithstanding variations of the latter from normal size when spread open.

2. Machine in accordance with the foregoing claim 1 and in which said reciprocable mounting means is also arranged to reciprocably carry therewith a portion at least of said mechanism for further spreading said elements.

3. A machine in accordance with the foregoing claim 1 and in which said ai-rpressure-operated means comprises a cylinder and piston device.

4. In a machine for automatically applying bags of sheet material to objects to be bagged therein, the machine having spaced-apart scoop-like elements, means for reciprocably mounting same to travel past the object to be bagged and to enter into the open mouth of a bag, a camoperated linkage mechanism being provided to then spread apart said elements somewhat further and into engagement with the interior surfaces of the mouth of the bag, said reciprocable mounting means then acting to retract said elements with the bag thereon and to pull the same into surrounding relationship to the object being bagged; the improvement which comprises providing in said mechanism an air pressure operated cylinder and piston device for applying a predetermined force as a pulling force acting through said mechanism to cause said scoop means to exert a predetermined spreading pressure against the interior surfaces of the mouths of the bags notwithstanding variations of the latter from normal size when spread open.

5. Apparatus in accordance with the foregoing claim 4 and in which said mechanism for spreading the elements further apart in the mouth of the bag is operably associated with said reciprocable means to move said elements closer together again after the object has been bagged.

6. In a machine for automatically applying bags of sheet material to objects to be bagged therein, the machine having spaced-apart scoop-like elements, means for reciprocably mounting same to travel past the object to be bagged and to enter into the open mouth of a bag, mechanism being provided to then spread apart said elements somewhat further and into engagement with the interior surfaces of the mouth of the bag, said reciprocable mounting means then acting to retract said elements with the bag thereon and to pull the same into surrounding relationship to the object being bagged; the improvement which comprises providing in said mechanism an air pressure operated means for applying a predetermined force acting through said mechanism to cause said scoop means to exert a predetermined spreading pressure against the interior surfaces of the mouths of the bags notwithstanding variations of the latter from normal size when spread open, a pressure-operable electrical switching means operably responsive to the air supply pressure to said air pressure operated means, to stop a motor drive for the machine when said pressure drops to a predetermined value below which said air pressure operated means will not effectively produce a sufiicient spreading pressure on said elements to maintain the bag thereon during the bagging operation.

References Cited UNITED STATES PATENTS 2,850,855 9/1958 Offuit 53-27 2,973,610 3/1961 Randall 53-188 3,358,414 12/1967 Hersh et 'al 53261 X THERON E. CONDON, Primary Examiner.

R. L. SPRUILL, Assistant Examiner.

US. Cl. X.R.