GB2256415A

GB2256415A - Method and apparatus for making triangular pyramidal tea bags

Info

Publication number: GB2256415A
Application number: GB9112095A
Authority: GB
Inventors: Joji Kataoka
Original assignee: Kataoka Bussan KK
Current assignee: Kataoka Bussan KK
Priority date: 1991-06-14
Filing date: 1991-06-05
Publication date: 1992-12-09
Anticipated expiration: 2011-06-05
Also published as: BE1004578A3; DE4119730C2; AU7808891A; FR2677606B1; GB9112095D0; GB2256415B; DE4119730A1; FR2677606A1

Description

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TITLE OF THE INVENTION

Method and Apparatus for Making Triangular Pyramidal Tea Bags BACKGROUND OF THE INVENTION

Field of the Invention The present invention relates to a method and an apparatus for manufacturing tea bags, particularly those of a triangular pyramidal shape, that are dipped in hot or cold water to extract the essence or ingredients of black or green tea.

Description of the Prior Art

This invention provides a method and an apparatus for making triangular pyramidal tea bags with high efficiency.

Triangular pyramidal tea bags have a container bag which is formed in a triangular pyramid in normal condition accommodating a space large enough not only for an appropriate amount of black tea or green tea sealed therein to absorb sufficient water without being pressed against the bag but also for a large amount of r.Tater to be admitted. This in turn assures effective extraction of tea essence out of the bag.

The only disadvantage of the triangular pyramidal tea bags is the greater difficulty in manufacture than the flat tea bags because of the special shape, which makes the production cost higher than that of the flat tea bags.

Among currently available means for making such 2 triangular pyramidal tea bags are those proposed by the Japanese Utility Model Preliminary Publication Nos. Showa 63-79303 and 63-99804. However, neither proposal has come up with a viable provision for ensuring continuous fabrication of the tea bags and therefore they cannot compete in terms of productivity with the apparatuses making flat tea bags.

SUMVIARY OF THE INVENTION The present invention has been accomplished to overcome the above- mentioned drawback in manufacture, i.e., the difficulty in performing continued production and therefore a low productivity.

As mentioned earlier, there have been put forward some proposals on the method of manufacturing triangular pyramidal tea bags. These methods can perform the manufacturing process continuously up to the point where a tape-like material is formed into a cylindrical shape. When, however, the cylindrical bag material is cut to a specified length and formed into a triangular pyramid or when the contents are loaded into the bag in synchronism with the cutting process, the feeding of tape-like bag material is stopped, halting the so-far continuous manufacturing process.

With a view to overcoming the problem of the abovementioned conventional methods, i.e., the interruption of 3 continued manufacturing, this invention provides a method and an apparatus that can make triangular pyramidal tea bags continuously while at the same time loading and sealing the tea contents without stopping the feed of bag material.

This invention makes triangular pyramidal tea bags through repetition of the following processes: a process of shaping a tape-like bag material into a cylindrical form; a first flattening process of flattening the cylindrically formed bag material along a straight lateral line perpendicular to the axial direction of the cylindrical bag material and, at the flattened portion, fusing and cutting the cylindrical bag material to form a bag; a process of supplying a substance into the bag at the same time that the above fusing operation is performed; a second flattening process of flattening, fusing and cutting, immediately following the substance supply process, the cylindrical bag material from a direction shifted 90 degrees from that of the first flattening process at a position above the previously fused and cut position in order to separate a triangular pyramidal tea bag from the bag material; a process of supplying a substance into the cylindrical bag remaining above the cut portion; and a process of flattening, fusing and cutting, immediately after the substance charging 4 process, the cylindrical bag from a direction shifted 90 degrees from that of the previous flattening process along a straight lateral line at a position above the previously cut portion. This invention is characterized in that the process of flattening, fusing and cutting the cylindrical bag material along a straight lateral line is performed at the same downward speed as the downward feed of the cylindrical bag. material, thereby allowing a continuous manufacture of the tea bags without any interruption of process flow.

To describe in more detail, the object of the invention is to provide a method of making triangular pyramidal tea bags, which comprises: a cylindrical bag material formation process consisting of the steps of: supplying a tape-like meshed material onto the circumferential surface of a vertically disposed supply cylinder, wrapping the meshed material around the entire circumferential surface of the supply cylinder and feeding the material along the length of the supply cylinder; abutting side margins of the material against each other along a vertical line on the surface of the supply cylinder; joining the contacting side margins of the material by a fusing means to form the tape-like material into a cylindrical bag material; and feeding the cylindrically formed bag material down the supply cylinder at a constant speed; a first fusing and cutting process consisting of the steps of: pressing intermittently a pair of opposing press pieces located directly below the supply cylinder against the cylindrical bag material to flatten it along a straight lateral line and cut the bag material along the flattened portion; a second fusing and cutting process being performed after the first fusing and cutting process and consisting of the steps of: pressing another pair of opposing press pieces, staggered 90 degrees from the first pair of opposing press pieces, against the cylindrical bag material to flatten it along a straight lateral line at a vertically different position than the straight lateral line of the first fusing and cutting process and cut the bag material along the flattened portion; and a substance charging process consisting of the steps of: throwing a substance from the supply cylinder into the bag material in synchronism with the first and second fusing and cutting processes; said first and second fusing and cutting processes causing the paired opposing press pieces to perform a circular or elliptical motion to clamp the cylindrical bag material at the same downward speed as the downward feed of the cylindrical bag material.

Another object of the invention is to provide an apparatus for making triangular pyramidal tea bags, which 6 comprises: a supply cylinder disposed vertically through which a substance is thrown into a cylindrical bag material, said supply cylinder being also used to shape a tape-like meshed material that is fed along'the length of the supply cylinder into a cylindrical form by wrapping the material over the circumferential surface of the supply cylinder; a pair of fusing means disposed facing each other on the circumferential surface of the supply cylinder to cause side margins of the tape-like meshed material wrapped around the supply cylinder to abut against each other and fuse them together to form a cylindrical bag material; a feed means in contact with the supply cylinder to feed the cylindrical bag material downwardly; a first fusing and cutting means disposed below the supply cylinder and having a pair of a fusing press piece and a receiver press piece disposed horizontally facing each other on the opposite sides of a vertical extension line of the supply cylinder, said pair of opposing press pieces being adapted to press, flatten and cut along a straight lateral line the cylindrical bag material being fed downward; a second fusing and cutting means disposed on the same horizontal plane as the first fusing and cutting means, said second fusing and cutting means having an opposing pair of a fusing press piece and a receiver press piece shifted 90 degrees from those of 7 the first fusing and cutting means to press, flatten and cut the cylindrical bag material along a straight lateral line at a position vertically displaced from the straight lateral line of the first fusing and cutting means; and an oscillating support mechanism that supports the opposing press pieces of the first and second fusing and cutting means in such a way that the opposing press pieces perform a rotary motion describing a circular or elliptical locus to horizontally clamp the cylindrical bag material being fed from the supply cylinder and at the same time move the clamped bag material downwardly the same speed as the vertical feed of the bag material A further object of the invention is to provide a triangular pyramidal tea bag making apparatus as mentioned above, in which said oscillating support mechanism comprises support arms supporting the press pieces at their front ends, oscillating support rods whose free ends are pivotally connected to intermediate portions of the support arms so that the support arms can be oscillated back and forth, and crank mechanisms connected to the rear end of each support arm to oscIllate the respective support arms about a fulcrum, which is the pivot point between the support arms and the oscillating support rods, and said crank mechanisms are rotated to cause said opposing press pieces to perform a repetitive 8 clamping and feeding motion describing a circular or elliptical locus.

A further object of the invention is to provide a triangular pyramidal tea bag making apparatus as described above, in which said fusing press piece consists of a fusing blade and a cover enclosing the fusing blade, said fusing blade is rigidly fixed to the front end of the support arms, said cover is normally urged by a spring installed between it and the support arm to project a slit formed at its front end forwardly beyond the tip of the fusing blade, and when said cover abuts against the receiver press piece, the front end of the cover is pushed and retracted to project and expose the fusing blade through the slit.

A still further object of the invention is to provide a triangular pyramidal tea bag making apparatus as described above, which further comprises a pair of expansion pieces made of a spring material, said expansion pieces being mounted on opposite portions of the supply cylinder side wall with respect to the center line of the supply cylinder in such a way-as to be slidable along the cylinder axis, said expansion pieces being driven in synchronism with the feed of the cylindrically formed bag material, said expansion pieces being adapted to project from a lower end opening of the supply 9 cylinder prior to the clamping operation of the fusing and cutting means to expand and flatten in opposite directions the cylindrical bag material being fed downwardly from the supply cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings represent one embodiment of this invention.

Figure 1 is a schematic perspective view with only essential components shown to indicate the positional relationship between them in the apparatus; Figure 2 is a front view of an essential portion of the apparatus; Figure 3 is a right side view of the apparatus; Figure 4 is an enlarged right side view of the essential portion of the apparatus; Figure 5 is an enlarged front view of a guide; Figure 6 is a right side view of the guide; Figure 7 is an enlarged plan view of a fusing press piece connected to a link mechanism; Figure 8 is an enlarged side view of the fusing press piece shown cooperating with a.receiver press piece to clamp a cylindrical bag material; Figure 9 is an enlarged side view of the fusing press piece shown cooperating with the receiver press piece to press, seal and cut the cylindrical bag material by fusing; Figure 10 is a diagram showing the locus of motion of the fusing press piece as a result of rotation of the crank mechanism; Figure 11 is an enlarged front view of a central vertical cross section of a supply cylinder with the expansion pieces expanded; Figure 12 is a side view of the supply cylinder partially cut away; Figure 13 is an enlarged front view of a central vertical cross section of the supply cylinder with the expansion pieces lifted; Figure 14 is a cross section taken along the line XX of Figure 11; Figure 15 is a cross section taken along the line YY of Figure 13; and Figures 16A, 16B and 16C are schematic views showing the expansion pieces being retracted.

DETAILED DESCREPTION OF PREFERRED EMBODIMENT The accompanying drawings show one embodiment of the invention. Figure 1 is a perspective view of the apparatus showing the positional relationship between components. Figure 2 is a schematic front view of the same. Figure 3 is a schematic side view of the apparatus. Figure 4 is an enlarged side view of an essential 11 portion of the apparatus.

The apparatus shown includes: a means to form a tape-like meshed bag material into a cylindrical shape; a means to feed the cylindrical bag material downwardly; first and second fusing and cutting means to clamp the fed cylindrical bag material along a straight lateral line from a direction perpendicular to the length of the cylindrical bag material and, at this clamped pos ition, fuse and cut the cylindrical bag material; and a supply means to supply contents of tea bag such as black tea or green tea into the cylindrical bag material in synchronism with the motion of the fusing and cutting means. The apparatus of the invention also includes a cylindrical bag material expanding means to ensure that the cylindrical bag material being clamped is correctly pressed and flattened along the straight lateral line. Now, the construction of each component of the apparatus will be described in reference to the accompanying drawings.

In the drawings, reference numeral 1 is a supply cylinder, around which a tape of meshed bag material 2 is wrapped to be formed into a cylindrical shape and through the hollow portion of which the contents such as black tea or green tea is introduced. Denoted 3 is a fusing means made up of two pairs of fusing pieces facing each 12 other which are mounted on the outer circumference of the supply cylinder 1; and 4 are feed rollers located one on each side of and in contact with the supply cylinder 1. First and second fusing and cutting means are located below the supply cylinder 1 and each has a fusing press piece 5, 7 and a receiver press piece 6, 8, which face each other from opposite sides with respect to an extension line of the supply cylinder.

The supply cylinder 1 consists of two cylinders la, 1b nested one inside the other and disposed vertically. The inner cylinder 1b is connected at the upper end with a metering device 9 that measures the amount of substance to be loaded in the tea bag. Above the metering device 9 is provided a hopper 10 that stores the substance.

The metering device 9 has a circular outer frame 11 in which is installed a rotating member 13 with metering recesses 12 formed in the circumference thereof. As a rotating shaft 14 rotates and when one of the recesses 12 comes immediately below the hopper 10, the substance is received into the recess. Then the rotating member 13 is turned. When the recess moves to the lowest position and faces the supply cylinder 1, it discharges the substance so that a specified amount of substance can be introduced into the supply cylinder. The rotating member 13 has two metering recesses 12 180 degrees apart so that it can 13 feed the metered substance into the supply cylinder 1 every half rotation.

The tape of the meshed bag material 2 is formed of fine meshes of synthetic resin and wound into a roll. The meshed bag material tape is given a specified tension through a plurality of guide rolls 15 and fed through a guide 16, which is shaped like a turn-down collar, onto the outer circumference of the supply cylinder 1, in this case the outer circumference of the outer cylinder la.

The guide 16, as shown in Figures 5 and 6, consists of a cylinder body 18 with a vertical cut 17 and a guide plate 20 shaped like a turn-down collar integrally provided to an upper end opening edge 19 of the cylinder body 18. The cylinder body 18 is fitted over the outer circumference of the supply cylinder 1, with the cut portion 17 positioned at the front.

The material 2 drawn out of the rolled tape by way of guide rolls 15 is supplied from the back of the supply cylinder 1 past the upper surface of the guide plate 20 to the upper end opening edge 19, at which the material 2 changes its direction and is fed downwardly through a space between the cylinder body 18 and the outer cylinder la of the supply cylinder 1. During this downward feeding, the side margins of the tape material 2 are passed through the cut portion 17 to make them abut 14 against each other. The abutting side edges or ears are further passed through the fusing means 3 to fuse them together at 2a to form the tape material into a cylindrical shape 21.

The feed rollers 4 turn to pull the tape material 2 downwardly toward the supply cylinder 1 and at the same time feed the cylindrically formed bag material 21 to the fusing and cutting means located below.

A set of fusing press piece 5 and receiver press piece 6 forming a first fusing and cutting means and another set of fusing press piece 7 and receiver press piece 8 forming a second fusing and cutting means are disposed on the same horizontal plane. The first and second fusing and cutting means are shifted 90 degrees from each other so that the first means faces the cylindrically formed bag material 21 from the front and back and the second means faces it from the right and left. These two sets of press pieces perform the clamping action alternately at time intervals.

Figure 4 shows the first fusing and cutting means that has its press pieces aligned in the longitudinal direction. Figures 7 to 10 show thedetails of the fusing press piece 5 and the receiver press piece 6 of the first means. The second fusing and cutting means is the same in construction as the first means and hence its explanation is omitted.

The fusing press piece 5 and the receiver press piece 6 are fixed at the facing ends of horizontally extending support arms 22, 23) to face each other, as shown. The support arms 22, 23 are supported by oscillating rods 24, 25, which are pivotally connected to the intermediate portions of the support arms and also by crank mechanisms 26, 27 pivotally connected to the rear ends of the support arms.

The oscillating rods 24, 25 are rotatably connected at the lower ends 28, 29 to a base frame of the apparatus not shown and, at the upper ends, are pivotally connected through pins 30, 31 to the intermediate portions of the support arms 22, 23 to sustain them. The crank mechanisms 26, 27 are rotated by shafts 32, 33 at one end thereof in the direction of arrow, and pins 34, 35 at the other end are pivotally connected to the rear end of the support arms 22, 23 to sustain them. Though not shown, the rotating shafts 32, 33 are turned at equal speeds.

The fusing press piece 5 cooperates with the opposing receiver press piece 6 to clamp the cylindrical bag material 21 to fuse and cut it. The fusing press piece 5 has a fusing blade 5a at the end that is applied with a high-frequency current, and also has a cover 36 enclosing the fusing blade 5a. The fusing press piece 5 16 is shaped like a thick and wide plate and has the tip formed into a sharp edge, over the entire width of which L.he fusing blade 5a is provided. The cover 36 is formed as a box containing the entire fusing press'piece 5 and is mounted longitudinally slidable. It is normally urged by a spring 38 installed between it and a support base 37 to project forwardly so that a laterally linear slit 39 at the front end of the cover 36 is pushed forward with the fusing blade 5a retracted inwardly of the cover 36. The cover 36 is made thinner toward the front end, which is formed with the lateral slit 39 so sized as to allow the fusing blade Sa to protrude therethrough.

As mentioned later, the fusing press piece 5 has a width such that when the cylindrical bag material 21 is pressed and flattened, the press piece 5 can grip the entire width of the flattened bag material 21. The receiver press piece 6 that opposes the fusing press piece 5 has its front end sharpened to allow the linear clamping of the material. The receiver press piece 6 also has a sufficient width that matches that of the fusing press piece 5.

The fusing press piece 5 and the receiver press piece 6 are operated by the crank mechanism 26, 27, which is driven by the shaft 32, 33 rotating in the direction of arrow. The opposing press pieces 5 and 6 clamp and 17 flatten along a straight lateral line the cylindrical bag material 21 fed down the supply cylinder 1 and then fuse and cut it. As mentioned earlier, the shafts 32 and 33 turn at equal speeds to drive the crank meclanisms in the arrow direction. As the crank mechanisms 26, 27 rotate in the arrow direction, the support arms 22, 23 pivoted on the pins 34, 35 are oscillated back and forth by the oscillating rods 24, 25, causing the fusing press piece 5 and the receiver press piece 6 attached at the front ends of the support arms to perform an elliptical rotary motion and cooperate with each other-to clamp the cylindrical bag material 21. The fusing press piece 5 and the receiver press piece 6 in the clamping condition feed the flattened portion of the cylindrical bag material 21 downwardly.

Figure 10 is a diagram of the loci of opposing press pieces 5, 6 showing how they perform elliptical oscillating and clamping motions as a result of the crank mechanism rotation. Reference symbol A represents the locus of the pin 34 of the crank mechanism 26; symbol B indicates the locus of the support arm. 22; C the locus of the oscillating rod 24; and D the locus of the fusing press piece 5 or more precisely stated, that of the fusing blade 5a. As the support arm 22 is oscillated back and forth by the rotation of the pin 34, the action 18 of the oscillating rod 24 makes the fusing blade Sa follow an elliptical rotary track. That is, the fusing blade Sa approaches the vertical line 40 that extends downwardly from the supply cylinder 1, while descending from the upper position. Then when it moves away from the vertical line 40, the fusing blade 5a gradually moves up from the lowest position. These processes are continuously repeated to flatten and feed the cylindrical bag material 21.

Figure 8 shows the fusing press piece 5 and the receiver press piece 6 just beginning to clamp by the link action the cylindrical bag material 21 being fed from the supply cylinder 1. Figure 9 shows the opposing press pieces further down the process fully clamping the cylindrical bag material 21. When the opposite press pieces 5, 6 abut against each other, the cover 36 enclosing the fusing press piece 5 is pushed back by the receiver press piece 6 contracting the spring 38, with the result that the fusing blade 5a protrudes through the lateral slit 39 and contacts the receiver press piece 6. By the pressing action of the two opposing press pieces, the cylindrical bag material 21 is pressed and flattened along a horizontal line at an intermediate position along its vertical length, and is fused by the fusing blade 5a to seal the interior of the cylindrical material. The 19 fusing blade 5a then cuts the fused portion of the bag material to separate the partitioned bag (which forms a tea bag as described later). The fusing action of the blade 5a also seals the cut portion of the remaining cylindrical bag material 21.

In the apparatus of this invention, when the cylindrical bag material 21 is fused and cut by the first fusing and cutting means, the metering device 9 is operated to discharge the specified amount of substance from the recess 12 into the supply cylinder 1 and then into the cylindrical bag material 21 whose lower end is sealed. This process of loading the substance is performed simultaneously with the elliptical motion of the fusing press Diece 5 and the receiver press piece 6. The substance loading operation is completed when the opposing press pieces 5, 6 part from each other and retract from below the supply cylinder. While the opposing press pieces 5, 6 are moving away and retracting from each other, the second fusing and cutting means is activated to advance the fusing press piece 7 and the receiver press piece g-which have the same construction as the counterparts of the first fusing and cutting means- from the left and right side toward a position directly below the supply cylinder 1, thus clamping the cylindrical bag material 21. The fusing press piece 7 has a fusing blade that fuses and cuts the flattened portion of the bag along a straight lateral line to separate a triangular pyramidal tea bag 41.

Since the second fusing and cutting means that advances its opposing press pieces from the left and right side has these opposing press pieces staggered 90 degrees with respect to the first fusing and cutting means, the tea bag can be automatically be formed into a triangular pyramid. With the cylindrical bag material 21 cut by the fusing and cutting means, the metering device 9 throws the substance into the supply cylinder. The fusing press piece 5 and the receiver press piece 6 of the first fusing and cutting means are advanced in the longitudinal direction to a position immediately below the supply cylinder 1 to flatten, fuse and cut the bag material along a straight lateral line, thus separating another tea bag 41.

In this way, the tape-like material 2 supplied onto the circumferential surface of the supply cylinder 1 is formed into a cylindrical shape 21. The cylindrically formed bag material 21 is fed down while at the same time the first and second fusing and cutting means are alternately activated. During this process the substance to be contained in the tea bag is intermittently supplied into the supply cylinder 1, thus forming the triangular 21 pyramidal tea bags 41 in succession.

This invention further incorporates a device that guides the cylindrical bag material 21 to be neatly flattened when the opposing press pieces 5, 6 of the fusing and cutting means clamp it.

Figures 11 through 16 show the means for guiding and flattening the cylindrical bag material 21. In the drawings, designated 42, 42 are expansion pieces and 43 an operation rod for advancing and retracting the expansion pieces.

The expansion pieces 42 are installed in a gap formed between the inner and outer cylinders la, lb of the supply cylinder 1. They are arranged vertically slidable on the right and left sides of the cylinder so that they are symmetrical about the center line of the supply cylinder. The expansion pieces 42 are formed of a strip of spring material with a narrow width and have their lower portions shaped to expand outwardly with a sliding projection 44 provided to the outer side of the lower end.

The operation rod 43 has a semicircular arm 45 at the end, which is formed with notches 46 at both ends into which are inserted pins 47 that- project outwardly from the upper end of each expansion piece 42 to connect the arm 45 and the expansion pieces 42. The rear end of 22 1 the operation rod 43 is secured to a rotating shaft 48 rotatably supported on a statignary frame not shown so that the front end of the operation rod 43 can be oscillated up and down. As shown in Figure 4, the rotating shaft 48 has a rearwardly extending oscillation arm 49, the rear end of which is urged downwardly by a spring 50. At an intermediate portion of the oscillation arm.49, a cam plate 51 is put in sliding contact with the underside of the arm. The cam plate 51 rotates about a shaft 52. A belt 55 is wound on a pulley 53 fixed on the shaft 52 and a pulley 54 on the rotating shaft 32 of the crank mechanism to synchronize the motion of the cam plate 51 with the fusing and cutting operation.

Figures 4, 11 and 12 show the opposing press pieces 5, 6 of the first fusing and cutting means clamping the cylindrical bag material 21 from the front and back to fuse and cut it. At this time, the cam plate 51 has its apex in contact with the oscillating arm 49 expanding the spring 50 and lowering the front end of the operation rod 43 with the rotating shaft 48 as a fulcrum. Lowering the front end of the operation rod 43 causes the expansion pieces

42, 42 on the left and right side to move down. As the lower portions of the expansion pieces 42 come out of the gap between the inner and outer cylinders of the supply cylinder 1, they expand 23 sideways, laterally expanding the cylindrical bag material 21, which is being fed down the outer circumferential surface of the supply cylinder. cylindrical bag material 21 is therefore formed longitudinally flat at this portion.

As explained above, since the lowering motion of the expansion pieces 42 and the clamping motion of the opposite press pieces 5, 6 are synchronized, the press pieces 5, 6 start approaching each other at the same time that the expansion pieces 42 begins to move down expanding and flattening the cylindrical bag material 21. When the expansion pieces 42 reach the lowest point, the fusing and cutting operation by the fusing press piece 5 and the receiver press piece 6 is finished, separating the triangular pyramidal tea bag 41 from the lower end of the cylindrical bag material 21.

In the embodiment shown, the expansion pieces 42 are provided one on each side of the supply cylinder 1 and operated only when the first fusing and cutting means acts on the cylindrical bag material 21. It is also possible to provide another pair of expansion pieces at the front and back of the supply cylinder and operate them when the second fusing and cutting means is activated to expand the cylindrical bag material in the longitudinal direction. In this embodiment, however, when the 24 z opposing press pieces 7, 8 are advanced from the left and right side of the cylindrical bag material, the vertical fused portion 2a (side margins fused together) of the cylindrical bag material functions as a folding guide along which the bag material is easily flattened, making it almost unlikely that the actual folding position will be deviated or the bag deformed. For this reason, the second expansion pieces are omitted in this embodiment.

The moment the first fusing and cutting means finishes the clamping operation and the opposing press pieces 5, 6 start retracting, the oscillating arm 49 begins to be released from the upward push of the cam plate 51, lifting the expansion pieces 42 (see Figure 13), with the result that the outwardly expanded lower portions retract into the gap between the outer and inner cylinders to allow the cylindrical bag material to return to the original shape. And the cylindrical bag material now in normal shape is ready for being pressed and flattened by the second fusing and cutting means.

In the drawings, denoted 56 is a belt conveyor installed below the supply cylinder 1,'onto which the formed tea bags 1 fall and are carried out of the apparatus.

The features and advantages of the invention may be summarized as follows.

The tape-like meshed bag material is formed into a cylinder, which is then flattened, fused and cut along a straight lateral line, during which process the substance is charged into the bag and the cylindrical bag material continues to be fed down the supply cylinder. This is followed by the similar operation of the second fusing and cutting means. The firs- L and second means are operated alternately to continuously make triangular pyramidal tea bags. Since all the processes-the supply of bag material, formation of cylinder, throwing the substance into bags, and formation and cutting of tea bags--are performed continuously without interruption, the productivity is greatly enhanced.

Two sets of fusing and cutting means arranged on the same plane are operated alternately to flatten, fuse and cut the cylindrical bag material. The opposing press pieces of these means are driven to describe a circular or elliptical locus. This arrangement allows continued flow of manufacturing process even when the tea bag is cut and separated. Since the opposing press pieces that have cut the tea bag are retracted horizontally to allow the downward feed of the cylindrical bag material, the bag material is prevented from contacting the fusing blade of the fusing press piece and therefore there is very little possibility of faulty products.

26 Another feature of the invention is that the cylindrical bag material is expanded and flattened in one direction by the expansion pieces before the opposing press pieces of the fusing and cutting mean! clamp the bag material, thus ensuring the cylindrical bag material to be folded and flattened at the correct position when clamped. This effectively prevents the bag material from being folded at wrong position or getting deformed out of triangular pyramid.

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Claims

1. A method of making triangular pyramidal tea bags comprising: a cylindrical bag material formation process consisting of the steps of: supplying a tape-like meshed material onto the circumferential surface of a vertically disposed supply cylinder, wrapping the meshed material around the entire circumferential surface of the supply cylinder and feeding the material along the length of the supply cylinder; abutting side margins of the material against each other along a vertical line on the surface of the supply cylinder; joining the contacting side margins of the material by a fusing means to form the tape-like material into a cylindrical bag material; and feeding the cylindrically formed bag material down the supply cylinder at a constant speed; a first fusing and cutting process consisting of the steps of: pressing intermittently a pair of opposing press pieces located directly below the supply cylinder against the cylindrical bag material to flatten it along a straight lateral line and cut the bag material along the flattened portion; a second fusing and cutting process being performed after the first fusing and cutting pr ocess and consisting of the steps of: pressing another pair of opposing press pieces, staggered 90 degrees from the first pair of opposing press pieces, against the cylindrical bag material to flatten it along a straight lateral line at a vertically different position than the straight lateral line of the 28 first fusing and cutting process and cut the bag material along the flattened portion; and a substance charging process consisting of the steps of: throwing a substance from the supply cylinder into the bag material in synchronism with the first and second fusing and cutting processes; said first and second fusing and cutting processes causing the paired opposing press pieces to perform a circular or elliptical motion to clamp the cylindrical bag material at the same downward speed as the downward feed of the cylindrical bag material.

2. An apparatus for making triangular pyramidal tea bags comprising: a supply cylinder disposed vertically through which a substance is thrown into a cylindrical bag material, said supply cylinder being also used to shape a tape-like meshed material that is fed along the length of the supply cylinder into a cylindrical form by wrapping the material over the circumferential surface of the supply cylinder; a pair of fusing means disposed facing each other on the circumferential surface of the supply cylinder to cause side margins of the tape-like meshed material wrapped around the supply cylinder to abut against each other and fuse them together to form a cylindrical bag material; a feed means in contact with the supply cylinder to feed the cylindrical bag material downwardly; a first fusing and cutting means disposed below the supply cylinder and having a fusing press piece and an opposing receiver press piece disposed horizontally facing each other on the opposite sides of a vertical 29 extension line of the supply cylinder, the opposing press pieces being adapted to press, flatten and cut along a straight lateral line the cylindrical bag material being fed downward; a second fusing and cutting means disposed on the same horizontal plane as the first fusing and cutting means, said second fusing an cutting means having a fusing press piece and an opposing receiver press piece shifted 90 degrees from those of the first fusing and cutting means to press, flatten and cut the cylindrical bag material along a straight lateral line at a position vertically different from the straight lateral line of the first fusing and cutting means; and an oscillating support mechanism that supports the opposing press pieces of the first and second fusing and cutting means in such a way that the opposing press pieces perform a rotary motion describing a circular or elliptical locus to horizontally clamp the cylindrical bag material being fed from the supply cylinder and at the same time move the clamped bag material downwardly at the same speed as the vertical feed of the bag material.

3. An apparatus for making triangular pyramidal tea bags as claimed in Claim 2, wherein said oscillating support mechanism comprises support arms supporting the press pieces at their front ends, oscillating support rods whose free ends are pivotally connected to intermediate portions of the support-arms so that the support arms can be oscillated back and forth, and crank mechanisms connected to the rear end of each support arm to oscillate the respective support arms about a fulcrum, which is the pivot point between the support arms and the oscillating supports rods, and said crank mechanisms are rotated to cause said opposing press pieces to perform a repetitive clamping and feeding motion describing a circular or elliptical locus.

4. An apparatus for making triangular pyramidal tea bags as claimed in Claim 2 or 3, wherein said fusing press piece comprises a fusing blade and a cover enclosing the fusing blade, said fusing blade is rigidly fixed to the front end of the support arms, said cover is normally urged by a spring installed between it and the support arm to project a slit formed at its front end forwardly beyond the tip of the fusing blade, and when said cover abuts against the receiver press piece, the front end of the cover is pushed and retracted to project and expose the fusing blade through the slit.

5. An apparatus for making triangular pyramidal tea bags as claimed in Claim 2, 3 or 4, further comprising: a pair of expansion pieces made of a spring material, said expansion pieces being mounted on opposite portions of the supply cylinder side wall with respect to the centre line of the supply cylinder in such a way as to be slidable along the cylinder axis, said expansion pieces being driven in synchronism with the feed of the cylindrically formed bag material, said expansion pieces being adapted to project from a lower end opening of the supply cylinder prior to the clamping operation of the fusing and cutting means to expand and flatten in opposite directions the cylindrical bag material being fed downwardly from the supply cylind er.

6. An apparatus for making triangular pyramidal tea bags substantially as hereinbefore described with reference to the accompanying drawings.

7. A method for making triangular pyramidal tea bags 31 substantially as hereinbefore described.

8. A tea bag manufactured by the method of Claim 1 or Claim 7 or manufactured by the apparatus of any one of Claims 2 to 6.

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