US3001341A

US3001341A - Bag closing machine and control means therefor

Info

Publication number: US3001341A
Application number: US860116A
Authority: US
Inventors: Ralph L Wing
Original assignee: Pneumatic Scale Corp
Current assignee: Pneumatic Scale Corp
Priority date: 1959-12-17
Filing date: 1959-12-17
Publication date: 1961-09-26
Anticipated expiration: 1978-09-26

Description

R. l.. WING 3,001,341

4 Sheets-Sheet 1 A TTOHNEY Sept. 26, 1961 BAG CLOSING MACHINE AND CONTROL MEANS THEREFOR Filed Dec. 17, 1959 sept. 26, 1961 LV1/m@ 3,001,341

BAG CLOSING MACHINE AND CONTROL MEANS THEREFOR Filed Deo. 1'7, 1959 4 sheets-shet 2 INI/ENTOR. Ra/p L. Wing f @www ATTORNEY Sept. 26, 1961 R. L. WING 3,001,341

BAG CLOSING MACHINE AND CONTROL MEANS THEREFOR Filed DSG. 17, 1959 4 Sheets-Sheet 3 l JNVENTOR. f90/ph L. W/'ng BY @MdL/.M

A TTHNEY R. L. WING Sept. 26, 1961 BAG CLOSING MACHINE AND CONTROL MEANS THEREF'OR 4 Sheets-Sheet 4 Filed Dec. 17. 1959 Pfg? JNVENTOR. /a/ph L. Wing BY mawem( United States Patent 3,001,341 BAG CLOSING MACHINE AND CNTRL MEANS THEREFUR Ralph L. Wing, Burlington, Mass., assigner to Pneumatic Scale Corporation, Limited, Quincy, Mass., a corporation of Massachusetts i Filed Dec. 17, 1959, Ser. No. 860,116

14 Claims. (Cl. 53-76) This invention relates to a bag closing machine.

The invention has for an object .to provide a novel and improved machine having provision for closing the extended mouth portion of a bag containing an article and which is characterized by novel control means adapted to discontinue operation of the machine in the event that the article is improperly positioned within the bag or the filled bag misaligned with respect to the bag closing mechanism to prevent damage to the article during the mouth closing and sealing operation and to enable an attractive, ecient mouth closure to be made.

. The invention has for another object to provide a novel and improved control means particularly adapted for use in a machine wherein a flat bag containing an article of merchandise is engaged at its mouth portion between opposed belts to be gripped and advanced into operative relation to mouth closing mechanism and which is characterized by its ability to detect relatively small abnormal separation of the belts and to discontinue operation of the machine in the event that a relatively thin misaligned portion of the merchandise is received between the belts.

With these general objects in View and such others as may hereinafter appear, the invention consists in the bag closing machine and in the control means as hereinafter described and particularly del-ined in the claims Vat the end of this specification. A

In the drawings illustrating the preferred embodiment of the invention:

FIG, l is a front elevation of a bag closing machine herein shown as a bag trimming and sealing machine embodying the present invention;

`FIG. 2 is a` plan view of a portion of the machine shown in FIG. l; g

g FIG. 3 is 'a side elevation detail view of the detecting mechanism forming a part of the control means, some of the parts being shown incross section; i

FIG. 4 is a view similar to FIG. 3 showing the parts in a different position of operation;`

FIG. 5 is a front elevation detail View of the detecting mechanism;

FIG. 6 is a vertical cross section of thedetectingrnechanism taken on the line 6 6 of FIG. 5 and FIG. 7 `is a wiring diagram illustrating the control circircuit for discontinuing operation of the machine in response to the detecting mechanism.

In general the present invention comprises an improvement in the bag trimming and sealing machine illustrated and described in a copending application, Serial No. 699,630, by Robert W. Saumsiegle, for Method and Apparatus for Trimming and Sealing Plastic Bags, filed November 29, 1957, and asigned to applicants assignee.

In the operation of the trimming and sealing machine disclosed in the Saumsiegleapplication, above referred to, a ilat ybag of thermoplastic material open at the mouth and containing an article of merchandise is placed on a conveyer with the open mouth portion extended laterally over one side thereof. The mouth portion is then engaged by opposed continuously moving gripping elements in the form of upper and lower metal belts or bands arranged to clamp the walls of the mouth portion together along a line spaced a relatively short distance from the edge of the merchandise contained in the bag, leaving a substantial portion of the'mouth extended beyond the tance from the metal belts.

ln practice it was found that through inadvertence the article might be improperly positioned within the bag and a portion of the merchandise might extend into the mouth portion of the bag, or the bag might be misaligned in a manner such that the opposed belts :would grip a portion of the merchandise therebetween and as a result when the bag was advanced to the hot wire the latter would effect burning of the merchandise or an improper closure effected.

yIn accordance with the present invention provision is made for detecting misalignment of the merchandise in the bag or of the bag relative to the opposed belts carrying the bags to the trimming and sealing mechanism and for discontinuing operation of the machine in the event that a portion of the merchandise contained in the bag is received between the belts so that the operator may realign and properly position the bag and the merchandise whereby to avoid damage thereto or to the trimming and sealing mechanism. ln practice the present control means is capable of detecting a relatively minute separation of the belts beyond Ithe normal separation, as dictated by the thickness of the mouth portion of the bag, whereby to detect even relatively thin Vportions of the merchandise within the bag which are inadvertently presented between the belts, the control means including means responsive to the detecting means for discontinuing operation of the machine.

Referring now to the drawings, in general the bag trimming and sealing machine embodying the present invention may comprise the machine illustrated and described in the Saumsiegle application, `above referred to, and only such portions of the machine essential to an understanding of the present invention will be herein described. .As herein illustrated, in the operation of the bag trimming and scaling machine a 4ilat bag 12 of thermoplastic material containing an article of merchandise 1l is placed horizontally on a conveyor belt 10 with the open mouth portion 14 extended laterally beyond one edge of the belt to present the extended mouth portion in alignment with the trimming and sealing mechanism. The conveyer belt lll may be continuously driven-in any usual or preferred manner, not shown, and the mouth portion 14 of each bag is rst engaged by opposed upper and lower flat belts lo, l for the purpose of bringing the opposed walls of the mouth together in substantially flat face-to-face contactlng engagement. Ilhe ilattened mouth portion is then presented between opposed upper and

lower metal belts

20, 22 which are preferably arranged Eat an angle with relation to each other and with relation to the horizontal plane of the mouth portion of the bag so that the contacting edges of the

belts

20, 22 cooperate to engage the mouth along a relatively narrow line of contact. While thus gripped between the metal belts, the mouth portion is advanced into engagement with a heated wire 24 to effect trimming of the extended portion of the mouth land sealing ofthe mouth by liqueiication and fusion of the plastic bag material. lAs illustrated in FIG. 1, the wire 24 may extend longitudinally between spaced, upright posts 70, 172 and is preferably arranged at a small angle relative to the horizontal plane of the mouth portion gripped between the metal belts or bands. The mouths of the bags may be initially aligned against an adjustable stop or guide member 26 to present the mouth portion between the mouth engaging belts and to present the extended portion of the mouth in the path of the heated wire 24.

The'opposed upper and

lower belts

16, 18 may comprise relatively narrow, flat and longitudinally` extended endless belts, the upper belt 16 being arranged to run over

end pulleys

28, 30 carried on

shafts

32, 34, and the lower belt 18 being arranged to run over

end pulleys

36, 38 carried by shafts 40, 42. The

pulleys

28, 36 may comprise drive pulleys fast on -their

respective shafts

32, 40 and connected to rotate in opposite directions by

spur gears

44, 46, the

idler pulleys

30, 38 being mounted to rotate on their respective shafts 34, 42. The

shafts

32, 34 and 40, 42 are carried by and extended from diverging

arms

48, 50 at each end of a horizontally extended bracket 52.

The

belts

16, 18 may comprise leather or like material possessing sufficient rigidity to press the opposed walls of the mouth portion of the bag or container in at contacting relation, as described, and provision is made for driving the belts at a linear speed equal to the speed of advance of the bags on the conveyor through driving mechanism shown in FIG. l. The driving mechanism includes a driving motor 84 connected through a speed reducer 86 to a bevel gear 88 on a shaft 90 in mesh with a bevel gear 92 on a shaft 94. The shaft 94 is provided with a pulley 96 connected by a belt 98 to a pulley 100 fast on the lower drive pulley shaft 40 which is connected to the upper drive shaft 32 by the

spur gears

44, 46 as described.

After the mouth portion 14 ofthe container is closed by the

belts

16, 18, the attened mouth is received between the angularly arranged upper and

lower metal belts

20, 22. As illustrated in FIG. 1, the metal belts initially engage the mouth portion at a point intermediate the length of the engaging run of the

mouth flattening belts

16, 18 so that both sets of belts are in engagement with the mouth portion `for the remaining length of the run of the

belts

16, 18. The

metal belts

20, 22 extend beyond the flattening belts, as shown, so that when the bag mouth is subsequently engaged by the heated Wire 24 it will be gripped between the metal belts only.

As herein illustrated, each metal belt is disposed at an angle of about 45 with respect to the horizontal plane of the mouth portion of the bag and at an angle of about 90 with respect to each other, so that the upper and lower faces of the mouth portion are engaged by the cooperating edges of the upper and

lower metal belts

20, 22, respectively, the upper and lower belts being preferably olfset relative to each other so that the thin or narrow edge of one belt may engage the marginal edge of the wide face of its cooperating belt. The

metal belts

20, 22, are arranged to run over upper and

lower pulleys

104, 106 and 108, 110, respectively, which are mounted on axes arranged at an angle of 45 as shown. The

belts

20, 22 are also arranged to travel atA a linear speed equal to the advance of the containers on the belt 10 and, as herein shown, the

drive pulleys

104, 108 are mounted fast on

shafts

112, 114, respectively, journaled in brackets 115 carried by the wall 116 of a frame member 118. Each

shaft

112, 114 is provided with a worm gear v120, 122, each of which-is in mesh with a worm 124 fast on a shaft 126 journaled in a bearing member 128 secured to the wall 116 of the frame. The worm 124 is arranged to be rotated through connections including a chain and sprocket drive`130 between the shaft 126 and the output shaft of a speed increasing unit 132. A second chainy and sprocket drive 136 connects the input shaft of the speed increasing unit to a drive shaft 138. The drive shaft 138l is provided with a bevel gear 140 in mesh with the bevel gear 92 forming a part of the main drive mechanism as described. The upper and lower pulleys 106, 110 which are also mounted on axes arranged at 4an angle of 45 as shown, are arranged to rotate on

shafts

142, 144, respectively, which are journaled in

brackets

146, 148 attached to a second wall 150 of the frame member 118. l

From the description thus far it will be observed that successive bags placed on the conveyor 10 and aligned with the guide member 26 are advanced to present the unsealed mouth portions thereof between the opposed upper and lower mouth attening and closing

belts

16, 18, and while thus held and advanced the mouth portions are engaged between opposed upper and lower angularly arranged

metal belts

20, 22 along a line spaced a short distance inwardly of the outer margin of the mouth portion and inwardly relative to the line of engagement of the liattening belts. Thereafter, when the bag mouth leaves the

belts

16, 18 and is only gripped between the extended portions of the

metal belts

20, 22, the leading edge of the bag mouth is advanced into intersecting engagement with the heated wire 24 to effect the trimming and sealing operation.

As illustrated in FIGS. 1 and 2, the present control means includes detecting mechanism indicated generally at 300 which is disposed adjacent the receiving end of the

metal belts

20, 22 at a point spaced a short distance forwardly from the vertical center line of the pulleys 106, 110. As shown in detail in FIGS. 3 and 4, the detecting mechanism 300 is mounted at an angle of about from the Vertical and at right angles to the upper angularly arranged metal belt 20 with which the detecting mechanism is designed to cooperate. The detecting mechanism includes a contact member in the form of a pointed metal member or needle 302 carried by and replaceably secured in a conducting bar 304 by a set screw 305 as shown in FIG. 5. The conducting bar 304' is attached to and insulated from a holder 306 pivotally mounted on a shoulder stud 308 secured to a supporting plate 310. The plate 310 is attached by bolts 312 to a block 314 extended fromand secured to a portion of the pulley bracket 146 by bolts 316.

As. illustrated in cross section in FIG. 6, the shoulder stud 308is provided with upper and lower bronze washers 318 to assure :free pivotal movement of the holder 306, and an angularly extended arm 320 of the holder is provided with an adjustable set screw 322 for cooperation with a stop block 324 secured to the supporting plate by bolts 325. A coil spring 326 connected between the arm 320 and the block is arranged to rock the holder in a counterclockwise direction to present the end of the contact needle 302 in spaced relation to the upper metal belt 20, the set screw 322 being adjusted .to vary the spacing between the contact needle and the belt. The Vset screw 322 may be locked in its adjusted position by a nut 323.

As illustrated in FIG. 6, the conducting bar 304 which carries the contact needle 302 at one end is insulated from the holder 306 by an intervening insulating strip 328, and the metal screws 330 securing the bar to the holder eittend through insulating bushings 332. As shown in FIG. 5, the other end of the conducting bar 304 is provided with a lead 334 forming a part ofv a 6-volt circuit 336 grounded through the machine frame as indicated at 338, 340 in FIG. 7. The circuit 336 includes a fuse 342 and a control relay 344 arranged to open the motor circuit 346 when the relay circuit 336 is closed by engagement of the metal belt 20 with the contact needle 302.

In the normal operation of the machine whenv the mouth portions of the` flat thermoplastic bags Vor containers 12 containing mechandise, such as a cloth garment, are received between the

metal belts

20, 22, normal separation of the belts equal to the thickness of opposed walls of the bag is not suicientto effect movement of the upper belt 20 into engagement with the contact needle 302, the spacing of the needle being illustrated in FIG. 3. However, in the event that the bag is misaligned or the mechandise in the bag is not properly positioned therein such that an edge of the mechandise is received between the belts, as shown in FIG. 4, the belts will be abnormally spread apart and the upper belt 20 moved into engagement with the contact needle 302, Vthus closing the circuit to the relay 344 and opening the motor circuit 346 to discontinue operation of the machine. Engagement of the belt 20 with the contact needle may es eirect rocking of the contact unit in a clockwise direction, the extent of such movement depending on the thickness of the mechandise engaged between the belts. Upon removal of the abnormally or improperly positioned bag, or proper positioning thereof, the belts return to their normal position, and the contact unit is returned to its initially adjusted position by virtue of the spring 326 to again permit the continuous operation of the machine, the motor circuit 346 being closed uponY removal of the contact 302 from contact with the belt 20.

In operation the contact needle 302 is preferably adjusted relative to the metal belt 20 by movement of the set screw 322 such as to provide a minimum clearance space between the belt 20 and the end of the needle 302 when the mouth portion of a properly lilled and positioned container is aligned between the

belts

20, 22. In practice the amount of clearance for normal operation of the machine may be in the order of four thousandths of an inch, such that the end of needle 302 just aviods contact with the belt whereby a minute increase in the spacing of the

belts

20, 22 causes the needle to contact the belt 20 and discontinue operation of the machine.

From the above description of the bag closing machine, herein shown as a bag mouth trimming and sealing machine, it will be seen that the present control means provides `a safety device having an extremely sensitive detecting mechanism adapted to discontinue operation of the machine in the event that a slightly greater than normal separation of the metal gripping and conveying

belts

20, 22 occurs, whereby to prevent advancement of a misaligned or improperly filled bag into operative relation to the trimming and sealing mechanism and to thus avoid damage to the merchandise, such as burning the same by its engagement with the hot sealing wire or to the trimming and sealing mechanism, and also to prevent the formation of unattractive or defective seals.

While the illustrated embodiment of the invention contemplates closing of a grounded relay circuit upon detection of abnormal separation of the belts to open the driving motor circuit, it will be apparent that the present control means may be used with advantage in a machine wherein the gripping and conveying belts are of a nonconductive material and wherein abnormal separation of the belts may rock the contact unit to actuate a switch to effect closing of a conventional non-grounded relay circuit whereby to open the motor circuit and discontinue operation of the machine. lIt will also be understood that the gripping belts need not be angularly disposed, as illustrated herein, but may be arranged in parallel planes and in facetoface engagement.

While the preferred embodiment of the invention has been herein illustrated and described as being embodied in a bag closing machine adapted for closing, sealing and trimming the mouth portions of containers formed of a thermoplastic material, it will be understood that the invention may be embodied in other types of machines for closing the mouth portions of various types of containers and for detecting the position of the container and/ or the articles within the container relative to the closing mechanism whereby to avoid damage to the articles during the sealing operation and to assure the formation of attractive, efficient closures or seals.

Having thus defined the invention, what is claimed is:

1. In a machine of the character described, in combination, means for closing the mouth portion of a container containing an article of merchandise, means engageable with the mouth portion for gripping and advancing containers into operative relation to said closing means, and control means cooperating with said mouth gripping and advancing means adapted to discontinue the operation of the machine in the event that a portion of the container and merchandise is engaged by said gripping and advancing means.

2. In a machine of the character described, in combination, means for closing the mouth portion of a container containing `an articleof merchandise, a pair of opposed driven belts engageable with the mouth portion of the container for gripping and advancing the container into operative relation to said closing means, and control means cooperating with said mouth engaging belts adapted to discontinue the operation of the machine in the event that a portion of the merchandise is gripped between said belts.

3. In a machine of the character described, in combination, means for advancing a container having an article of merchandise therein through a predetermined path, said means including a pair of opposed driven belts between which a portion of the container is gripped, and control means actuated by abnormal separation of the opposed driven belts adapted to discontinue operation of the machine when a portion of the article in the container is received between the belts.

4. Control means as defined in claim 3 including the detecting means normally spaced a minute distance from one of said belts whereby to discontinue operation of the machine upon relatively slight movement of one of the belts into engagement with the detecting means.

5. VIn a machine of the character described, in combination, means for closing the extended mouth portion of a bag containing an article of merchandise, means for supporting and advancing the bag into operative relation Yto said closing means including a pair of opposed driven belts `between which the extended mouth portion of the bag is gripped, and control means including detecting means cooperating with said belts arranged to detect abnormal separation thereof, and means responsive to said detecting means for discontinuing operation of the machine when a portion of the merchandise in the bag is received between the belts.

6. In a machine of the character described, means for supporting and advancing a bag having an open mouth portion and containing an article, said means including a pair of opposed driven members between which the mouth portion is gripped, and electrical control means including a contact member cooperating with and normally spaced from said opposed driven members arranged to detect `abnormal separation thereof, and means responsive to engagement of said contact member by at least one of said driven members for discontinuing operation of the machine when a portion of the bag containing the article is received between said driven members separating the same abnormally. l i

7. Control means as delined in claim 6 wherein the opposed driven members comprise electrically conductive -belts and form part of a relay circuit arranged to be closed when at least one of the belts engages the contact member to discontinue operation of the machine.

8. In a machine of the character described, in combination, means for supporting and advancing a flat bag of relatively thin material having an open mouth portion and containing at least one article of merchandise, said means including a pair of opposed, relatively thin metal bands between which the mouth portion of the bag is gripped, and control means comprising detecting means including a contact member arranged to be engaged upon abnormal separation of the gripping bands, and means responsive to said detecting means adapted to discontinue operation of the machine when any portion of the merchandise yin the bag is received between the bands, said contact member being normally spaced from the bands a relatively small distance in the order of a few thousandths of an inch whereby to assure detection of a minute abnormal separation of the belts due to the reception of any portion of the article of merchandise in the bag between the bands.

9. In a machine of the character described, a frame, means supported in the frame for advancing a bag having an open mouth portion and containing an article of 7 mouth portion is gripped, means for driving said belts including a motor having a circuit, and electrical control means including a relay circuit grounded through said frame and said belts and arranged to control said motor circuit, said relay circuit having -a contact member insulated from the frame, said contact member being normally spaced from and arranged to be engaged by one of said belts to close said relay circuit to eiect opening of said motor circuit and discontinue operation of the machine upon abnormal separation of the belts by the merchandise and engagement of the contact by at least one of the belts.

10. Control means as defined in claim 9 wherein the contact member is mounted for pivotal movement when engaged by said one belt to compensate for the amount of separation of the belts caused by the thickness of the merchandise between the belts.

11. vControl means as deiined in claim 9 wherein the relay circuit comprises a low voltage circuit and the contact member includes a contact needle arranged to engage said one belt.

12. Control means as definedin claim 9 wherein the contact member includes a contact needle mounted for pivotal movement when engaged by said one belt, and means for adjusting the normal spacing between the belt and the needle.

13. In a machine of the character described, container advancing means engageable with a normally article free portion of a container provided with an article of merchandise, said advancing means` being adapted to ad- Vance the container through a predetermined path to be sealed, and control means adapted to discontinue operation of the machine to avoid damage to the article in the container by the sealing means, said control means being actuated by the engagement of the container advancing means with the control means when a portion of the article extends into the normallyarticle free portion of the container containing the article of merchandise.

14. In a machine of the character described, in combination, means engageable with an article free portion of a container for `advancing a container containing an article of merchandise through a predetermined path, and control means including detecting means adapted to cooperate with said advancing means to detect the position of an article of merchandise improperly positioned within the normally article free portion of the container and adapted to discontinue operation of the machine in the event the article of merchandise is detected to be improperly positioned within the container.

References Cited in the file of this patent UNITED STATES PATENTS 1,689,428 Farmer Oct. 30, 1928 2,715,807 Irmscher Aug. 23, 1955 v2,797,793 Wilde et al July 2, 1957 ravi.)