US2676556A

US2676556A - Bag stitching machine

Info

Publication number: US2676556A
Application number: US237038A
Authority: US
Inventors: Thorval J Lockwood
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-07-16
Filing date: 1951-07-16
Publication date: 1954-04-27
Anticipated expiration: 1971-04-27

Description

4.0. www4 April 27, 1954 Filed July 16, 1951 T, J. LocKwooD 2,676,556

BAG STITCHING MACHINE 2 Sheets-Sheet 1 INVENTOR. 7km/44 J aar/wap fram/fr proved machine. Vcured to and*` supported byanupri'ght channel:

Patented Apr. 27, 1954 UNITED STATES TLNT -OFFICE 2 Claims.

'This invention relates to a bag or sack sewing -machine of the type used for sealing bags or sacks of sugar, salt, potatoes, and other commodities. and more particularly to means for feedn ing sacks to and through such a machine.

highly eilicient means for automatically starting the sewing head of the machine when a bag is in proper position to be stitched, and to provide automatic means for cutting the stitching thread and stopping the stitching head at the terminal tion of the stitching or sewing operation.

Other objects and advantages reside in the `detail construction of the invention, which is designed ior simplicity, economy, and emciency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawing which forms a Apart hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawings:

Fig. 1`is a plan view of the improved portable bag-stitching machine;

Fig. 2 is a side view thereof;

Fig. 3 is an enlarged, vertical cross-section, taken on the line 3-3, Fig. l;

Fig. 4 is a similarly enlarged, fragmentary, end View, illustrating a thread-cutting mechanism employed in the improved machine; and

Fig. 5 is a detail, perspective view, illustrating a, machine-starting switch employed on the improved machine.

The improved bag stitcher is mounted on a reactangular base frame ill which is portably supported upon four caster wheels i I mounted in wheel brackets i2. The wheel brackets extendoutwardly and upwardly from the extremities of the base frame lll so as to allow the latter to be positioned in close proximity to the floor.

A sewing machine or stitching head I3 of any of the standard varieties is employed in the im- The stitching head I3 lis semember I4 arising from the rear edgeofvthe base' frame Ill. The stitching head I3 is driven from an electric motor I5 through the medium of a drive belt I6 and driven pulley Il.

Four spools of stitching twine or thread I8 are supported upon spool pins it extending upward from a spool platform I9 supported above the upper extremity of the channel member I4 on bracket members 6I. Only two of the spools lil are in use at one time. However, by having four spools on the spool plate I9, two full spools are always available for quick replacement of two exhausted spools.

Four upright, tubular standards 20 arise from the corners of the base frame I8 in rectangular, spaced relation. An elongated conveyor frame 2| is supported by the standards 2li through the medium of set collars 22 which are vertically adjust-able on the standards. The collars 22 are welded or otherwise permanently attached 'to the conveyor frame 2l and may be set at any desired height on the standards 20 by means of suitable set screws 23.

The conveyor frame supports two terminal belt rollers Eil between which an endless conveyor belt 25 is trained. The upper reach of the belt slides on a belt-supporting plate, and the discharge extremity of the latter plate is inclined slightly downward, as indicated at 25.

= The feed extremity of the conveyor frame is provided with a feed platform 2E, and the discharge extremity is provided with a similar delivery platform 2l. The conveyor belt 25 is actuated through the medium of a suitable transmission chain 28 extending from a suitable speed-reduction mechanism 29 which is driven by means of a second electric motor 3G. The conveyor belt 25 is positioned below the needle of the stitching head i3 and acts to convey sacks or bags, such as indicated at 3l, through the stitching head from the feed platform 26 to the delivery platform 27.

The discharging bags are supported and guided by means of two vertically and angularly adinstable guide arms which are mounted on two of the standards Eli, and which may be set in any desir-ed position thereon by means of suitable set'screws 33.

Ae the aligned sacks 3i travel toward the stitching head I3, the necks of the bags are gripped between two opposed, traveling, endless belts 34. Each belt 35i extends from a relatively large belt drive pulley t5 positioned at one side of the conveyor frame 2| to `a relatively small,

driven pulley 3S immediately alongside the stitching head I3. The two driven pulleys are placed relatively close together so that the two belts will be held in substantial contact with each other. They are maintained in Contact for a portion of their length by means of two idler pulleys 56, which are rotatably supported in an inverted, U-shaped yoke 55 supported from a .supporting frame 38. Each of the idler pulleys 5B is combined with a resilient press roller 59 positioned above the pulley. The press rollers are in substantial, horizontal alignment with the needle ci the stitching head I3 and act to press and smooth out any wrinkles or folds in the necks of the sacks beiore the latter pass into the embrace of the two gripping belts 34.

The drive pulleys 35 are mounted on vertical drive shafts 3l journalled in the supporting frame 38 at each side of the conveyor frame 2l. The shafts 3l! are driven in opposite directions by means of sets of suitable bevel gears 39 from a horizontal, transvcrsally-extending gear shaft 4U journalled in the base il). The gear shaft l0 is driven in desired manner, such as by means of a drive chain dl extending to the speed reducer 29 so that motor 3@ will operate both the gripping belts 3d and the conveyor belt 25.

As the sacks approach the stitching head I3, they engage a feeler lever 42 which is adjustably mounted on the lower extremity of a vertical switch-operating shaft 43. ing shaft is rotatably supported in the angle iron frame 38 and extends downwardly to a position alongside the path of the entering sacks. A cylindrical cam member @il is mounted on the upper extremity of the shaft d3. The edge of the cam member llt is inclined, as shown at lill, and rides beneath and supports one extremity of a hinged switch-supporting member elii. The other extremity of the switch-supporting member is hingedly mounted, as shown at 55. The member 45 carries a conventional, circuit-closing, mercury switch il which is connected in circuit with the stitching head motor I5. Thus, when the ieeler lever t?. is swung toward the stitching head I3 by the advancing sacks, the raised portion of the cam member M will slide beneath the switchsupporting member t5 to tilt the mercury switch Ill so as 'to cause the latter to close the circuit to the stitching head motor I5 to start operation of the stitching head I3. When the sack has passed completely through the stitching head I3, it will release the feeler lever 42 and allow a return spring itil to return. the feeler lever 42 to its off position to receive the next sack. The return movement of the feeler lever will rotate the cam member to allow the mercury switch 4l to return to its tilted, open-circuit position. Suitable stops G3 are provided on the cam member d which contact the sidesI of the switch-support ing member to limit the arc of movement thereof. The cam-actuated switch mechanism illustrated in Fig. 5 is enclosed in a suitable protective housing 5f; on the complete machine.

Stitching heads of the type used on bag-closing devices are provided with poweroperated, threadmutting knives which function during the operation of the sewing head. These knives are a part of the stitching head, and form, per se, no part of this invention. The normal position of these knives is indicated on the drawing by the numeral fle. In the usual machine the operator pushes the thread, indicated at 5&1., forwardly into the knives to sever the last-.stitched bag from the stitching head or from. the next bag being stitched. In this invention the thread is pushed Fhe switch-operatinto the knives automatically by means of a solenoid plunger 50 having a thread-engaging head 5I. The head 5I is retracted out of the normal path of the thread by means of an electric solenoid 52 and the head 5I is forced forwardly into contact with the thread by means of a compression spring 53. The solenoid 52 is connected in the circuit to the stitching head motor I5.

Thus, whenever the motor circuit is closed to start the stitching head I3, the solenoid 52 will be energized to retract the plunger 5D and the head 5 I. When the stitched bag has passed completely through the stitching head I3, the motor circuit will be broken at the mercury switch 41 to de-energize the solenoid 52, allowing the spring 53 to force the shoe 5I into engagement with the thread so as to force the latter into the cutting knives 39 to sever the thread. It will be noted that the motor circuit is broken at the same time the solenoid is de-energized, but the stitching head will continue to coast for a sunlcient interval to operate lthe cutting knives.

It can be seen from the above description that the wheels II allow the entire machine to be quickly and easily moved to the job, and that the set screws 23 allow the conveyor frame 2| to be easily adjusted vertically so as to bring sacks of any given size into alignment with the stitching head 3.

It will also be noted that it is unnecessary for the operator to attend the machine other than to place the open sacks on the belt 25. The machine will automatically start whenever a sack approaches the stitching head, and will automatically stop and sever the stitching twine whenever the stitching operation is completed.

The inclined portion 25 of the discharging xtremity of the conveyor belt 25 tilts the tops of the sacks away from the stitching head as they emerge from the latter. The purpose of this tilting action is to tighten the thread between the last-stitched sack and the stitching head so that it will be in proper position to be engaged by the spring-actuated head 5I on the solenoid plunger 50. If the conveyor were horizontal throughout its length the sacks would remain approximately vertical, and the threads connecting the successive sacks might bow downwardly as they leave the stitching head so that they would not be engaged by the head 5I and would not be pushed into the cutting knives 59. The supporting frame 38 is held in proper space relation with the stitching head by means of a suitable tie brace 51.

While a specific form of the improvement has been described and illustrated herein, it is to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

l. Automatic means for starting a motor driving a stitching head on a bag stitching machine comprising: a feeler lever positioned to be contacted by said bags; a switch operating shaft supporting said lever and extending upwardly therefrom; a cylindrical cam member concentrically mounted on the upper extremity of said shaft and having an upwardly-extending camshaped periphery; a tiltable switch supporting member hingedly mounted at its one extremity adjacent said cam member and resting adjacent its free extremity upon said camshaped periphery; a circuit closing mercury switch in circuit with said motor mounted upon said tiltable switch supporting member so that when said feeler arm rotates said cam member, through the medium of said shaft, said caln-shaped periph- 6 withdraw said plunger from engagement with said line of stitching against the action of said spring, said solenoid being in circuit with said mercury switch so as to be energized simultaneery will move beneath said switch member to tilt 5 ously with said stitching head motor.

the latter to cause said mercury switch to close the circuit to said stitching head motor to start a line of stitching across and connected to said bag.

2. Automatic means for starting a motor driving a stitching head on a bag stitching machine as described in claim 1, having thread cutting blades operable by said stitching head and positioned at one side of the line of Stitching connected to said bag; a plunger positioned on the opposite side of said line of stitching from said cutting blades; a spring urging said plunger against the line of stitching to force the latter into cutting engagement with said cutting blades; and an electrode solenoid adapted to References Cited in the 1e of this patent UNITED STATES PATENTS Number Name Date 1,044,301 Tucker Nov. 12, 1912 1,170,303 McNeil Feb. 1, 1916 1,321,232 Miller NOV. 11, 1919 1,377,624 Ostrom et al May 10, 1921 2,164,501 Cundall et al. July 4, 1939 2,282,200 Neuman May 5, 1942 2,293,686 Alien Aug. 18, 1942 2,423,080 Belcher et al July 1, 1947