US3518807A - Tying apparatus - Google Patents

Description

July 7, 1970 A. R. PITKANEN TYING APPARATUS 8 Sheets-Sheet 1 Filed Nov. 22, 1967 July 7, 1970 A. R. PITKANEN 3,518,807

TYING APPARATUS Filed Nov. 22, 1967 8 Sheegs-Sheet 2.

July 7, 1970 A. R. PITKANEN TYING APPARATUS 8 Sheets-Sheet 5 Filed NOV. 22, 1967 A. R. PITKANEN TYING APPARATUS July 7, 1970 8 Sheets-Sheet 4 Filed Nov. 22, 1967 \IIJ I' u u .llll llIllllll lllll July 7, 1970 A. R. PITKANEN 3,513,807

I TYING' APPARATUS Filed Nov. 22, 1967 8 Sheets-Sheet 5 I N VE NTOR 4244/ Z firmM/z/ y 7, 1970 A. R. PITKANEN 3,518,807

TYING APPARATUS Filed Nov. 22, .1967 8 Sheets-Sheet 0 IN\-"ENTOR.

414/1/ A. firml/a A. R. PITKANEN TYING APPARATUS July 7, 1970 8 Sheets-Sheet '7 Filed Nov, 22, 1967 y 1970 A. R. PITKANEN 3,

TYING APPARATUS Filed NOV. 22, 1967 8 Sheets-Sheet 8 United States Patent 3,518,807 TYING APPARATUS Alan R. Pitkanen, Newport Beach, Calif., assignor, by

mesne assignments to Royal Industries, Inc., Pasadena,

Calif, a corporation of Delaware Filed Nov. 22, 1967, Ser. No. 685,182 Int. Cl. B65b 51/08 U.S. Cl. 53-67 17 Claims ABSTRACT OF THE DISCLOSURE Tying apparatus for automatically tying articles with tie material capable of being twisted to form a tie upon the automatic and successive presentation of articles to be tied and tied thereto and automatically ejected from the tying apparatus.

The automatic tying apparatus when particularly adapted for tying open mouthed bags is adapted to automatically gather the bag neck upon presentation of the bag thereto in its path to the tying station. The tie mate rial is automatically delivered to the tying station so that as the bag is travelling towards the tying station, the tie material is wrapped around the bag to be tied upon itself at the tying station. At the tying station the tie material is cut from its length simultaneously with the twisting operation. Upon completion of the tying operation the bag is ejected from the tying apparatus and the apparatus is in condition to receive the next bag to be tied.

RELATED APPLICATIONS This application is related to the copending application bearing Ser. No. 406,960, filed Oct. 23, 1964, entitled Tying Apparatus, now Pat. No. 3,369,573, and assigned to the same assignee as the present application and which patent is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to apparatus for twisting ties about bags having an open end and similar articles. More particularly this invention relates to such apparatus adapted to automatically and successively gather the open end of a bag into a closed neck prior to tying the bag closed.

State of the prior art Apparatus for tying open end bags have been in use for some time. Generally they fall in two classes. According to the first such class articles to be tied on bags are manually inserted into the apparatus. Thereafter the apparatus is energized and performs the tying operation. The tied article is then manually withdrawn. An example of such an apparatus is disclosed in the above mentioned copending, commonly owned patent application bearing Ser. No. 406,960 and filed on Oct. 23, 1964, and now Pat. No. 3,369,573.

The second class of bag tying apparatus automatically gathers the open ends of the bags and automatically transport them to adjacent the tying mechanism proper. These prior art apparatus are complicated and costly to construct. They have a plurality of members that move towards and away from the article being tied to perform their assigned function. The article being tied enters and leaves the apparatus in an essentially straight path. Since a drive unit of the apparatus is always on one side of that path some of the movable components which are disposed on the other side of the path must be elevated to not interfere with the moving path. This increases the complexity and cost of prior art tying apparatus significantly. To maintain the components in proper working order is relatively expensive and often difficult. Thus, there is a need at the present time for an automatic tying apparatus which is small, of light weight, and which comprises relatively few and inexpensive components.

SUMMARY OF THE INVENTION This invention provides apparatus for closing and tying bag-like articles with tie material capable of being twisted to form a tie. Briefly, it may comprise continuously operating means for transporting the articles to be tied to adjacent a tying location. Open ends of the articles are then gathered to form a closed neck. Wrapping means engage an end of the tie material and place it around their neck. Tying means sever the portion of the tie material wrapped around the neck from the remainder thereof. This portion is twisted upon itself and about the neck to tie the article closed. Positive ejecting means act independently of the continuously operating means, remove the tied article from the tying location and eject it from the apparatus.

Preferably, the wrapping means include a pivotable member which engages and holds the portion of the tie material. This assures that the tie material is accurately positioned relative to the tying means which, when twisting the material, remove it from the member. A shield is also provided adjacent the tying means, which are preferably rotatable twisting and cutting heads, to prevent the article from contacting the rotating head.

The ejecting means include a fork shaped ejector which is actuated after the article has been tied, it moves the article over an ejector plate which disengages the two to enable return of the ejector to the tying location for the next cycle. The ejector moves the article in a direction which is transverse to the direction in which the article is moved towards the tying location. This enables full utilization of available space and permits the cutting and twisting head to be aligned with one of the directions in which the article travels in the apparatus. The apparatus is substantially simpler to construct and operate than prior art apparatus performing comparable operation since fewer components must be elevated to provide a free passageway for the bag moving toward and away from the tying location.

To prevent bags, particularly thin plastic bags, from adhering to portions of the apparatus adjacent their path to and from the tying location, surfaces of the apparatus in the vicinity of that path are preferably provided with a low friction surface. Excellent results have been obtained when applying a low friction coating of the type sold under the trademark Teflon to the surfaces. Even prolonged heat generation from the apparatus itself and from friction between the bags moving at high speeds and the surfaces of the apparatus facing and contacting the bags do not cause their adherence thereto.

As compared to prior art tying apparatus an apparatus constructed in accordance with the present invention has substantially fewer, more simple and rugged component parts. This reduces its original manufacturing costs as well as its maintenance costs. In addition down times of the apparatus from failures of intricate mechanisms found in prior art tying apparatus have been substantially eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of the tying apparatus constructed in accordance with the present invention, with parts being removed therefrom;

FIG. 2 is a side elevation taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged, fragmentary plan view of the tying apparatus similar to that shown in FIG. 1 and shows ejecting forks in phantom lines in an ejecting position;

FIG. 4 is a fragmentary elevational view, in section, taken along line 44 of FIG. 3;

FIG. 5 is a fragmentary end view, with parts removed, taken along line 5-5 of FIG. 2;

FIG. 6 is a fragmentary enlarged elevational view taken along line 6-6 of FIG. 1;

FIG. 7 is an enlarged plan view of a programming plate employed by this tying apparatus;

FIG. 8 is an elevational view of the programming plate shown in FIG. 7; and

FIG. 9 is a fragmentary sectional view taken along line 7--7 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description a typing apparatus 16 is described as being employed for tying an open end (not shown) of a conventional bag such as an ordinary polyethylene bag. A preferred installation of the tying apparatus contemplates its use for tying such bags as commonly used for the packaging of loaves of bread. It it to be understood, however, that the tying apparatus can be used for tying bags of any configuration and constructed of other materials. Moreover, the tying apparatus can also be used for tying articles to each other rather than closing a bag. The term article as used in this specification therefore is intended to and does include all articles which can be tied to each other, which can be tied closed, or which can be tied otherwise by this apparatus and the term is not limited to the tying of plastic bags only.

Briefly, articles, such as a bag 18 (shown in FIG. 3) enter the tying apparatus 16 through transport and gathering means 20 in a first direction. The gathering means close the open end of the bag and form a neck at a tying location 22 (shown in FIG. 1). Thereafter tying means 24 (see FIG. 3) tie the bag closed and the bag is ejected from the apparatus by ejecting means 26 which transport the bag in a second direction transverse to the first. The tying means 24 is not specifically described in detail herein but is described in detail in the copending patent application bearing Ser. No. 406,960, filed on Oct. 23, 1964, mentioned hereinabove, and which disclosure is incorporated herein by reference. The necessary elements to effect the twisting, tying and cutting of the tie material is described hereinafter in conjunction with FIG. 4.

Preferably, the apparatus is installed adjacent an automatic conveyor (not shown) which transports bags to be tied to and away from the apparatus 16. The tying apparatus is installed to receive the bags in a standing position, wherein the open end of the bag points vertically upwards, or in a lying position, in which the bag is horizontally disposed.

Referring to FIGS. 1, 3, and 9, a motor 28 is mounted on a housing 30. Through a conventional chain drive 32, best seen in FIG. 5, the motor drives a drive shaft 34 which projects through an opening 36 in the housing 30. Adjacent its outer end the drive shaft mounts a sprocket 38 of the chain drive 32. Interiorly of the opening 36 it mounts a gear 40 of a gear train 42 which continuously drives the transport and gathering means 20.

A belt housing 44, best seen in FIG. 9, mounts a shaft 46 on a pair of ball bearings 48. A gear 49 couples shaft 46 with the gear train 42. An end of shaft 46 opposite from the gear 49 mounts a pulley which drives an endless rubber belt 52.

The belt housing 44 includes a fixed axle 54. A sleeve 56 is rotatably mounted on the axle and driven by the rubber belt 52. An end of the sleeve opposite from its end in engagement with the rubber belt includes a pair of spaced apart, V-shaped grooves 58. An endless trans port belt 60 is disposed in each of the grooves plane parallel to the rubber belt 52.

The belt housing 44 additionally includes a support bracket 62 for purposes to be described subsequently. The bracket 62 is spaced apart from the sleeve 56 and extends away from the housing in a direction parallel to the axle 54. It is disposed between parallel strands of the rubber belt 52. A pair of spaced apart idler wheels 64 have a V-shaped groove identical to and aligned with grooves 58 in sleeve 56. The transport belts are looped over the idler wheels and rotate the idler wheels when the sleeve 56 is rotated. The idler wheels are mounted in slots 68 (see FIG. 3) of a cover 66 which is connected with bracket 62 as more fully described hereinafter. The cover engages and mounts the free end of the axle 54 and has a configuration enabling the transport belt to project past its outline.

The diameter of the portion of the sleeve containing the V-shaped grooves 58 is substantially greater than the diameter of the idler wheels 64 (see FIG. 3). An idler wheel is therefore disposed on each side of the axle 54 such that the transport belt 60 is guided in a straight line between the sleeve 56 and each idler wheel 64. The sleeve and the idler wheel are positioned closely adjacent a path the article to be tied takes when it is transported to the tying location 22. The slots 68 permit proper adjustment of the idler wheels relative to the path of the article.

The belt housing 44 also includes an aperture 70 aligned with screws mounting the cover 66. Access is thereby provided for installing and removing the cover.

Referring to FIGS. 1, 2, and 5, a pair of belt housings 44 are arranged side by side. A straight portion of the transport belt 60 of each is parallel to the path the article to be tied takes when transported to the tying location 22. The belts are biased into contact with each other by a spring 71 disposed in an L-shaped member 72 and acting through a pawl 78. One of the housings 44, say the righthand belt housing shown in FIG. 5, is fixed relative to the main housing 30. An end of its axle 54 is disposed in the generally L-shaped support member 72 secured to the main housing. A portion of the member which is parallel to the chain drive 32 (see FIG. 5) includes a plunger 74 which is axially movable by a handle 76 pivotally mounted on the member. Another end of the plunger adjacent the other belt housing 44 engages the pawl 78 adapted to engage a bracket 80 secured to the other belt housing 44.

When the pawl engages the bracket 80 the pivotable belt housing 44 is biased toward the stationary housing to bring opposing belts 60 into contact and enable them to transport articles to be tied. Actuation of the handle 76 disengages the pawl 78 from the bracket 80. The belt housing which mounts bracket 80 can now be pivoted about a cylindrical portion 81 (shown in FIG. 9) of the belt housing 44 away from the fixed belt housing 44.

Referring to FIGS. 1, 3, 4, 7, and 8, a programming plate 82 is keyed to a drive shaft 84 coupled with drive shaft 34 through a conventional single revolution clutch 86 (shown in FIGS. 4 and 5). A ball bearing 81 mounts shaft 84 in housing 30. A nut 83 axially secures the shaft to the bearing and further permits axial adjustment of the shaft and the programming plate for purposes described hereinafter. A compression spring between the ball bearing and the programming plate biases the latter against a shoulder 87 of the shaft.

The programming plate includes a first raceway 88 adjacent one side and a second raceway 90 adjacent another side for purposes described below. It also includes a gear segment 92, which is preferably integrally constructed with the plate, and a bevel gear segment 94 which is secured to the plate by a plurality of rivets 96.

The bevel gear segment engages a pinion 98 secured to a shaft 100 which is rotatable in the housing 30 on a pair of ball bearings. Axial adjustment of the programming plate 82 with the nut 83 permits accurate relative positioning of the bevel gear segment and the pinion. A spur gear 102 drives a twister shaft 104 also rotatably mounted in the housing; see FIG. 4. A free end of the shaft 104 projects past the housing and mounts a tying head 106. The tying head has a Z-shaped configuration and defines a pair of arcuate slots 108 which have an open end.

The twister shaft 104 is mounted in a bushing 110 adjacent its free end. Centered on the bushing is a die plate 112 which defines an aperture (not shown) through which tie material for tying the articles is advanced.

Also mounted on the free end between the bushing 110 and the tying head 106 is a cutting blade 114 which is biased towards the die plate 112 by a compression spring 116. The cutting blade has a cutting edge (not shown) which passes over the aperture (not shown) in the die plate 112 during each revolution of the twister shaft 104, thereby severing the tie material projecting through that aperture.

Disposed around the tying head 106 and aligned with a face thereof facing towards the tying location 22 is a guard or shield 118. The guard is suitably secured to the housing 30 (see FIG. 3). It prevents portions of the article being tied by the apparatus from becoming engaged or entangled with the rotating tying head.

Referring to FIGS. 1 through 3, tie material is preferably of a continuous length and stored on a rotatable spool 122 secured to the housing adjacent a rear end thereof. The tie material is guided from the spool over a braking mechanism 124 to a guide 126 mounted on the housing substantially plane parallel with the aperture (not shown) in the die plate 112. A drive disc or wheel 128 is mounted on a shaft 130 and is disposed adjacent the guide 126. The periphery of the drive wheel includes a recessed groove 132 having a width about equal or slightly greater than that of the tie material 120. Another disc or wheel 134 is mounted on a pivotable bracket 136, engages the groove 132 in the drive wheel 128 and is driven by the drive wheel through a pair of gears 135 disposed in the interior of housing 30. Preferably, the periphery of the wheel 134 includes a resilient liner 138, such as rubber for example. The pivotable bracket 136 is connected with a tension spring 140 which biases the driven wheel 134 towards the drive wheel 128. This causes firm contact between the tie material 120 and the peripheries of the two wheels. A single revolution of the drive wheel therefore advances a length of tie material which equals the circumference of its groove portion 132.

The shaft 130 projects into the interior of the housing 30 to adjacent the periphery of the programming plate 82. It mounts a gear (not shown) which engages the gear segment 92 of the programming plate each time the programming plate is rotated through one revolution. Thus during each actuation of the programming plate a preselected length of tie material 120 is advanced.

The tie material 120 extends through a suitable passageway in the housing 30 of the tie apparatus to the aperture (not shown) in the die plate 112. The advancing preselected length of tie material moves through the said aperture, an arcuate slot 108 in the tying head 106 is aligned with the aperture and hence into an opening 142 in a reciprocable needle 144.

Referring now to FIG. 3, a portion 145 of the housing 30 extends past the tying head 106 adjacent the side of the tying head which mounts the pivotable belt housing 44. An outermost end of the portion 145 mounts an arcuate guide plate 146 which is slightly recessed from an outline of the transport belt 60 when the movable belt housing 44 is pivoted to adjacent the stationary belt housing. A similar guide plate 148 is mounted between the transport belt 60 on the stationary belt housing 44 and is secured to the bracket 62. The cover 66 of the stationary belt housing is secured to the guide plate 148 by a screw 149 extending through a slot 149A to provide for adjustability of the cover.

The arcuately shaped needle 144 is pivotally mounted on a shaft 150 secured to the portion 145 of the housing 30. The needle includes a web 152 and a slot 154 defined by the web which is arranged to be aligned with the axis 6 of the twister shaft 104 when the needle is pivoted to position the web adjacent the tying head 106.

Referring to FIGS. 3 and 4, a connecting rod 156 is pivotally secured to the needle 144 and a bell crank 158. Another end of the bell crank is mounted on a shaft 160 journaled in the housing 30 and secured to an arm 162 disposed interiorly of the housing. The arm mounts a cam follower 164 which engages the first raceway 88 in the programming plate 82. Rotation of the programming plate by the drive shaft 84 thereby reciprocates the needle from its position shown in FIG. 3 into a position wherein the web 152 is adjacent the tying head 106 and a bag (not shown) to be tied there.

The ejecting means 2 6 include a pair of forks 166 and 168 which are secured to a shaft 170 projecting into the interior of the housing 30. The forks include a long arm 172 which nests in a recess 174 defined by the portion 145 of the housing 30 and a relatively short arm 176. The two arms are disposed in either side of the tying location 22 when the fork is in an original position. Both forks have a configuration to clear the guard 118 around the tying head 106. They are arranged such that the arms 172 and 176 of each fork are disposed on each side of the tie material 120 advancing through the aperture (not shown) in the die plate 112 or being tied round the article to be tied.

The inner end of the shaft 170 mounts a short arm 178 which slidably engages an elongated rod 180. The rod includes a nut (not shown) to prevent the arm from axially moving off its adjacent end. The opposite end of the rod includes a mounting portion 182 defining a shoulder and which is pivotally secured to an arm 184. A compression spring 186 is disposed between the shoulder defined by the mounting portion 182 and the short arm 17-8 and biases the arm towards the nut (not shown) of the rod 180. The nut is positioned such that the spring 186 biases the long arms 172 of the forks 168 into engagement with the recess 174 before it engages the stop pin. The arm 184 is pivotally mounted on a shaft 188 secured to the housing 30 and includes a cam follower 190 engaging the second raceway 90 of the programming plate 82.

Rotation of the programming plate pivots the arm 18 4 about shaft 188. The rod and the stop pin (not shown) thereon transmit this movement to shaft 170, thereby pivoting the forks 166 and 168 in a clockwise direction, as viewed in FIG. 3. The forks pivot from the tying location 22, through an arc into an ejecting position shown in phantom lines in FIG. 3. The long arms 172 of the forks pass between the idler wheels 64 and in the ejecting position project past an outline of an ejector plate 192 secured to the housing 30.

The ejector plate is preferably constructed of a low friction material such as tetrafluoroethelene, fluorocarbon or similar plastic materials. These materials are commonly known on the market under the trademark Teflon of the E. I. du Pont de Nemours and Co. Inc., of Wilmington, Del. Alternatively it can be constructed of metallic material which has subsequently been coated with such a low friction material. The ejector plate has an outline which gradually projects beyond the circular path of the short arms 176 of the forks. The tied neck of a bag 18 being ejected by the forks is thereby biased further and further away from the fork into the piston it is shown in FIG. 3. Return of the forks into their original position commences after the tied bag no longer interferes with the movement of the forks.

The forks may additionally be arranged such that the neck of a bag that has been tied and which is being ejected is biased towards the transport belts 60 during its movement towards the ejector plate 192. The movement of the transport belts thereby aids in the removal of the bag from the tying location.

The forks can be manually operated independently of the actuation of the programming plate 82 to remove articles being tied from the tying location even if the apparatus has been deenergized. The upper fork 166 is grasped and pivoted in a clockwise direction, as viewed in FIG. 3, against the biasing force of spring 186. Upon release of the fork the spring returns it to its original position in the indentation 174.

Referring to FIGS. 3,5, and 6, the tying apparatus includes a trigger mechanism to engage the single revolution clutch 86 every time an article to be tied is placed between the arms 172 and 176 of the forks 166 and 168 adjacent the tying location 22. A pawl 194 is pivota'ble about a pivot pin 196 secured to the guide 146. The pawl includes a nose 198 which projects into an undercut 200 in the guide 148. The nose of the pawl therefore projects transversely across the path of the article being transported to the tying location by the transport belts 60. A hook 206 connected with a self-centering microswitch 208 holds the pawl transversely to the path of bags being transported to the tying location 22 by the belts 60. In its transverse portion the pawl is in engagement with an end 202 of the undercut 200. The hook 206 is secured to the pawl in an arcuately shaped slot 204. Pivotal movement of the pawl in a clockwise direction, as viewed in FIG. 3, until it clears the path of the article being transported to the tying location closes electric contacts (not shown) in the switch to energize an electric circuit between the switch, a solenoid 210 and a power source (not shown). The switch is opened again when the pawl returns to its original position in which it is transverse to the path of the bags.

Referring to FIG. 5, the solenoid 210 includes an axially movable plunger 212 which, in its relaxed position, is in the position shown in solid lines and referenced 212A. An end of the plunger remote from the solenoid includes a recessed portion 214 defining a shoulder 2 16 and an axially disposed slot 218. A sleeve 220 is axially movable on the recessed portion 214 and includes a transverse pin 222 disposed within the slot 218. Movement of the sleeve is therefore limited by the engagement between the pin and the slot.

A compression spring 224 biases the sleeve and the plunger away from each other. The pin 222 extends beyond the side of the sleeve and is furthermore engaged by a slot 226 of an arm 228 secured to a shaft 230 extending into the interior of the housing 30. The other end of the shaft mounts an elongated hook 232 which engages a pin 234 of the clutch 86. A spring 236, shown schematically only, biases the hook in a clutch pin engaging direction at all times.

Energization of the solenoid moves the plunger 212 to the left into the position shown in phantom lines and referenced 212B. The engagement between the hook 232 and the clutch pin 234 prevents any motion of the arm in an counterclockwise direction. The plunger therefore compresses spring 224 and thereby stores energy in the spring. Deenergization of the solenoid releases this energy which throws the plunger to the right beyond its original position, as shown in phantom lines identified by the numeral 212C. This sudden movement of the plunger imparts a hammer blow onto pin 222 which is transmitted to the hook 232 and rotates the hook in a counterclockwise direction, as seen in FIG. 5, against the biasing force of spring 236.

After the plunger reached its extreme position spring 224 returns it to its relaxed position (212A). Spring 236 is thereby permitted to return the hook 232 into its clutch pin engaging position. During the time interval hook 232 is disengaged from clutch pin 234 the clutch begins to rotate. After it has rotated on full revolution the clutch pin is again engaged by the hook and the clutch is deenergized. Repetition of the just described process again rotates the clutch 86 through one revolution. Thus, a clockwise rotation of the pawl 194, as viewed in FIG. 3, energizes the solenoid. Subsequent release and counterclockwise rotation of the pawl after the bag to be tied has passed it deenergizes the solenoid causing hook 232 to release the clutch 86 for a single revolution. The programming plate 82 thereby actuates the various mechanisms of the tying apparatus.

Turning now to the operation of the tying apparatus 10, it is assumed that the apparatus is installed adjacent a suitable conveyor (not shown) which delivers bags 18 to adjacent the guides 146 and 148 in an upright position as described at the beginning of this specification. The electric motor 28 has also been energized to rotate sprocket 38 and drive shaft 34. This in turn activates the transport belts 60. A bag being delivered to adjacent the guides 146 and 148 is grasped by the belts, its open end is progressively flattened, and it is transported towards the tying location 22.

The bag entering between the belts pivots the pawl 194 in a clockwise direction, as viewed in FIG. 3, and energizes the solenoid 212. Those portions of the flattened bag entering the tying location 22 are there formed into a closed neck (not shown) which is positioned by the arms 172 and 176 of the forks 166 and 168, and by the belts 60. After the last end of the bag passed the pawl 194, it returns to its original position. The electric circuit of the solenoid 212 is thereby opened and the plunger 212 returns to its original position, permitting one revolution of the clutch 86 and the programming plate 82.

It is assumed that the preselected length of tie material has been advanced past the die plate 112 and through the opening 142 in the needle 144. The first and second raceways 88 and 90, the gear segment 92 and the bevel gear segment 94 are arranged such that the needle is first pivoted into a position adjacent the closed neck of the bag at the tying location. During the pivotal movement of the needle the length of tie material 120 projecting past the die plate 112, which has its free end engaged by the needle, is wrapped around the neck through an angle of about The opening 142 in the needle is positioned such that the free end of the tie material can be engaged by the tying head 106 and one of its arcuate slots 108 when the head rotates. The slot 154 in the web 152 of the needle furthermore engages the closed neck of the bag being tied and maintains it tightly closed.

After the needle has wrapped the length of tie material around the neck of the bag the bevel gear segment 94 of the programming plate 82 engages the pinion 98 and rotates it. Its rotation causes rotation of the tying head 106 and the cutting blade 114. The rotating tying head twists the parallel portions of the tie material about each other and onto the closed neck of the bag, thereby tying the bag closed. Simultaneously the cutting blade severs the length of tie material projecting past the die plate 112. Practice has shown that about one and a half to two revolutions of the tying head is all that is needed to securely twist the ends of the tie material on each other and tie the bag.

While the tie head twists the tie material it removes the free end from its engagement with the needle in the opening 142. Thus, the needle positively maintains the preselected length of the tie material in position until it is twisted to the bag. The first raceway 88 now returns the needle into its original position.

After termination of the twisting operation the second raceway 90 actuates the ejector to remove the now tied bag from the tying location 22. It does so in a direction which is transverse to the first direction in which the article to be tide moves toward the tying location 22. This has the advantage over removing the bag in a direction parallel to the first of providing more usable space for placing the various mechanisms of the apparatus.

Tying apparatus 16 assures a uni-directional movement of the bags. Bag can enter between the drive belts on a continuous basis. The apparatus is therefore adapted to tie a substantially greater volume of bags than apparatus which eject the tied bags in the same direction in which they enter it.

After the ejecting means 26 have begun to remove the tied bag, or simultaneously therewith, the gear segment 92 of the programming plate 82 begins to drive wheel 128 to advance a preselected length of tie material. Tie material leaving the aperture (not shown) in the die disc 112 is positively guided in grooves 238 defined by the portion 145 of the body until the free end of the tie enters the opening 142 in the needle 144. Movement of the tie along a predetermined path is thereby secured. Accidental deflection of the tie or bending of it while it advances, which would prevent it from taking its assigned position and can lead to a failure of the apparatus, are thereby prevented.

It is advantageous to advance the length of tie material 120 used for tying the next bag at the end of a complete tying cycle when there is no bag ot the tying location. The presence of the bag can cause the tie material to become hung-up on it. The advancing material would then be deflected and prevented from becoming engaged by the needle. The bag being ejected at the end of the cycle would not be tied and the apparatus malfunctions.

To prevent operation of the apparatus when no tie material is available a sensor 240, shown in FIG. 2, is mounted on the housing 30 adjacent the guide 126. If tie material 120 is depleted the sensor opens the electric circuit of the motor 28 and deenergizes the motor. No more bags can be tied until a spool 122 of new tie material has bee-n mounted.

The rapid operation of the apparatus requires the braking mechanism 124, shown in FIG. 2, to prevent unravelling of the tie material on the spool 122. Preferably, the braking mechanism includes a pivotally mounted arm 242 which is biased into engagement with the periphery of the spool 122 by a spring 244. The frictional force prevents rotation of the spool except when the arm 242 is disengaged therefrom. Advancing of tie material by the wheels 128 an 134 temporarily pivots the arm 242, which mounts an idler wheel 246 over which the tie material is looped, since the spool is prevented from rotating by its engagement with the arm 242. The disengagement permits rotation of the spool until the arm is again in engagement with it. The length of tie material removed from the spool equals the length advanced by the wheels 128 and 134.

Referring to FIGS. 1, 2, and 6, a hingably mounted cover 248 is secured to the housing and prevents portions of the tying means 24, the ejecting means 26 and the triggering mechanism from coming into contact with articles moving to and away from the tying location 22. Preferably, a spring 250 biases the cover into a closed position.

A top cover 252 is also provided to encapsule the chain drive 32 and the solenoid 210 and to prevent their contamination. An electric switch 254 for energizing the motor 28 projects past the top cover.

Prolonged operation of the machine frequently causes its temperature, including the temperature of covers 66 and 248, to rise. If the articles being tied are bags constructed of thin, thermoplastic material, portions of the bag coming into contact with these covers may adhere to the covers, thereby causing the bags to be torn. High speed operation of the apparatus increases this danger. To prevent the bags from adhering to the covers the latter are preferably coated with a low friction material such as the above referred to material being traded under the trademark Teflon. Uninterrupted high volume tying of bags made possible by the tying apparatus of this invention is thereby assured.

I claim:

1 Apparatus for closing and tying articles with tie material capable of being twisted to form a tie, the apparatus comprising:

(a) continuously operating means for transporting the articles to be tied in a first direction to adjacent a tying location and for gathering the article there to form a neck;

(b) means for forming an essentially U-shaped portion of tie material around the neck;

(c) rotatable tying means for severing the U-shaped portion from the remainder of the tie material and for twisting said portion upon itself and about the neck to tie the article closed;

(d) a reciprocating ejector grasping the article adjacent the tied neck and removing it from adjacent the tying location in a second direction transverse to the first direction; and

(e) feeding means for advancing a preselected length of the tie material to be formed around the neck.

2. Apparatus according to claim 1 wherein portions of the apparatus adjacent a path of the article toward and away from the tying location have low friction surfaces exposed to an article being transported toward and away from the tying location.

3. Apparatus according to claim 2 wherein the ejector includes a fork disposed adjacent the tying location, an arm of the fork being positioned on each side of the tied tie material, and wherein the fork is movable in the sec ond direction, and including an ejector plate cooperating with the fork for positively disengaging the bag from the fork when the bag has been removed from the tying location.

4. Apparatus according to claim 3 wherein the tying means include a rotatable cutting and twisting head, wherein the feeding means advance the tie material after actuation of the ejector through an aperture positioned to enable the cutting and twisting head to engage the advanced tie material, and wherein the forming means include a reciprocable member having an opening into which the tie material is advanced.

5. Apparatus according to claim 4 including a drive cam for operating the forming means, the tying means, the ejector and the feeding means in response to an article being transported to the tying location, and including a linkage coupling the fork with the cam and constructed such that the fork is selectively manually movable in the second direction.

6. Apparatus according to claim 5 including a guard shielding the cutting and twisting head and preventing the article positioned at the tying location from becoming engaged by said head when it rotates.

7. Apparatus according to claim 4 wherein the portion of the tie material extending through the opening in the member is withdrawn therefrom by the rotating cutting and twisting head.

8. Apparatus for closing and tying articles with tie material capable of being twisted to form a tie, the apparatus comprising:

(a) a program plate rotatably mounted in a housing;

(b) means for grasping the article to transport it to a tying location and for forming a neck;

(c) trigger means for sensing the presence of an article at the transport means;

(d) means responsive to the operation of the trigger means for rotating the plate a predetermined amount;

(e) means for storing a continuous length of tie material;

(f) means for placing a preselected length of tie material around the neck of the article to be tied;

(g) a cutting and twisting head actuated by the plate for severing the tie material from the continuous length and twisting the preselected length about itself thereby tying the article closed; and

(h) a movable fork shaped ejector actuated by the plate and grasping the article adjacent the twisted tie material.

9. Apparatus according to claim 8 wherein the ejector is pivotally movable and including an ejector plate for removing the article from the fork shaped ejector when it pivots from a position adjacent the cutting and twisting head to one remote therefrom.

10. Apparatus according to claim 9 wherein the placing means include a pair of cylindrical discs biased towards each other for advancing the preselected length of tie material, at least one of the discs being actuated by the plate.

11. Apparatus according to claim 9 wherein portions of the apparatus in the vicinity of the path of the moving article and facing toward the article have a low friction surface to prevent heat from causing the article to adhere to such a surface.

12. Apparatus according to claim 11 wherein the transport means includes a belt disposed adjacent each side of the path of the article moving toward the tying location and wherein at least one of the belts is removable from adjacent said path.

13. Apparatus according to claim 12 wherein the trigger means include a pawl projecting into said path defined by the transport means and movable out of the path by an article being transported.

14. Apparatus according to claim 13 including drive means coupled with the programming plate through a single revolution clutch and means coupled with the trigger means for activating the clutch in response to an article having been transported past the pawl.

15. Apparatus according to claim 9 including a linkage connecting the ejector with the programming plate, the linkage being constructed to enable manual operation of the ejector without activation of the plate.

16. Apparatus according to claim wherein the storing means include a rotatable spool storing the tie material and an idler wheel mounted on a pivotable arm which is biased into engagement with the spool to prevent its rotation, the tie material being arranged such that actuation of the discs temporarily disengages the arm from the spool.

17. Apparatus for closing and tying bag-like articles with tie material capable of being twisted to form a tie, the apparatus comprising:

(a) drive means for rotating a program plate mounted in a housing a predetermined amount;

(b) a pair of spaced apart transport belts defining a path for an article to be tied in a first direction, one of said belts being movable away from the path, the belts being arranged to grasp an open end of the article, transport it to a tying place and there form a closed neck;

(c) trigger means operatively connected with the drive means and including a movable pawl projecting into said path for sensing the presence of an article in the path and actuating the drive means to rotate the plate said predetermined amount;

(d) a spool rotatably connected with the housing for storing a continuous length of tie material;

(e) means for normally preventing rotation of the spool, the tie material being guided from the spool past the means for preventing the rotation of the spool and through an aperture in the housing to pass adjacent the tying location;

(f) a pair of rotatably mounted cylindrical discs biased towards each other and into engagement with the tie material, at least one of the discs being coupled with the plate and rotated a predetermined amount in response to rotation of the disc;

(g) a pivotally mounted member coupled with and activated by the plate, the member being disposed adjacent the tying location and having an opening through which an end of the preselected length of tie material advanced through said aperture extends, the member being arranged to wrap the end of the tie material engaged by the opening through an arc of about 180 to form an essentially U-shaped length of tie material around the neck;

(h) a cutting and twisting head adjacent said aperture and the tying location for severing the U-shaped portion from the continuous length of tie material, for removing the tie material extending through the opening in the member therefrom, and for twisting the tie material about itself and the article to tie the article;

(i) guard means disposed around the twisting head for preventing portions of the article from contacting the head;

(j) a pivotally mounted fork-shaped ejector adjacent the tying location grasping the neck of the article adjacent the tie and pivotally movable away from the tying location in a second direction transverse to the first, the ejector being coupled with the plate such that it removes the article from the tying location after the U-shaped portion of tie material has been twisted; and

(k) an ejector plate arranged eccentrically relative to the pivot point of the ejector for disengaging the ejector and the article at a location remote from the tying location, the plate having a configuration and being arranged such that the cylindrical discs are actuated after actuation of the ejector.

References Cited UNITED STATES PATENTS 7/1966 Platt et a1 53135 6/1955 Gray 53l35 2/1968 Jarund 53138 X 2/1968 Baker et al. --93.6

878,447 9/1961 Great Britain.

THERON E. CONDON, Primary Examiner N. ABRAMS, Assistant Examiner US. Cl. X.R. 53135; 14093.6

Images