EP0166078B1

EP0166078B1 - Swingable claw for wrapping machine

Info

Publication number: EP0166078B1
Application number: EP19850102194
Authority: EP
Inventors: Masao Funo; Noburo Yoshikawa
Original assignee: Japan Tobacco Inc
Current assignee: Japan Tobacco Inc
Priority date: 1984-06-19
Filing date: 1985-02-27
Publication date: 1988-02-24
Also published as: JPS615701U; JPH018487Y2; DE3561643D1; EP0166078A1

Description

The present invention relates to a wrapping machine having a swingable claw as indicated in the preamble of the claim.
In prior art, a conventional wrapping process is effected as, for example, shown in Figs. 2 to 8. As shown in Fig. 2, soft wrapping paper P cut to prescribed dimensions is moved down into a wrapping passage. As shown in Fig. 3, a product A to be wrapped such as a pile of cigarettes is pushed forward into the soft wrapping paper P by a pusher 1 and the product and the paper are passed through between an upper and a lower guide plates 16 (shown in Fig. 9) so that the paper P is wound as U on the product A. The product A and the paper P are pushed forward further by the pusher 1 so that a swingable claw 2 waiting in a closed position performs the front end face folding P, of the paper P, as shown in Fig. 4. The product A and the paper P are then pushed forward furthermore so that a guide plate 3 holds the end face folding P, of the claw 2. At that time, the pusher 1 finishes pushing the product A and the paper P forward and the swingable claw 2 is opened to a non-folding position, as shown in Fig. 5. A lower portion folding plate 4 is then moved up to perform a lower portion folding P₂, as shown in Fig. 6. An upper portion folding plate 5 is then moved down to perform an upper portion folding P₃, and the lower portion folding plate 4 is simultaneously moved down, as shown in Fig. 7. The swingable claw 2 is then turned to the closed position to perform a rear end face folding P₄, as shown in Fig. 8.
Another wrapping means similarly operated and comparable in performing the wrapping process is comprised in the art according to US 2 584 529. In order to form the tucks along vertical front and rear edges of the wrapping bag, said machine comprises stationary flaring ears, supported by rigid vertical sideplates respectively, which engage the leading vertical wall portions at each side of the bag, thus forming the respective leading tucks in the process of conveying the product through their wrapping passage. In order to perform the rear end face folding along the rear vertical side edge, a swingable resilient claw mechanism is provided at both sides of the wrapping line. The claw means, merely provided for performing the rear end face folding along the vertical rear edge of the product, comprises an arcuate plate member which is connected hingedly to a radial arm of a rotatable sleeve supported by a pivotable rock shaft which, via an associated fixed lever, makes the radial arm with the arcuate plate connected by a hinge swing inwardly in order to perform folding operation. While the arcuate plate is normally moved concentrically, during the formation of the tuck it may yield as required by respective preloading springs, urging the arcuate plate in a home position with respect to the associated radial arm, said home position being adjustable by a setting screw provided at the rear end of the arcuate plate and abutting against the radial arm to which the arcuate plate is hingedly connected. Moreover, a return spring is provided which enables the freely rotatable sleeve with the radial arm and the associated arcuate plate to return to its withdrawn home position after the forming of the tuck has been completed.
However, with such an arrangement, difficulties have been encountered in performing exactly and neatly the intended rear end face folding along the vertical rear edge folding line, in particular, when relatively soft folding paper has been used.
In the art, when the swingable claw performs the rear end face folding, the soft wrapping paper is not bent exactly along the folding line of its folded portion, due to the locus of turning of the end of the swingable claw. For this reason, there is a problem that said folded portion becomes loose or the rear end face folding is not neatly performed.
Another wrapping device for folding sidewardly projecting flaps of wrapping material is disclosed in GB-PS 953 551. The apparatus shown therein has a swingable arcuate claw member and, hingedly connected thereto, a leading folding roller arrangement controlled by a guide roller engaging a cam control profile supported by the wrapping device.
However, the design of said apparatus involves a plurality of rather complicated parts requiring exhaustive machining and, moreover, the different motions of the roller support swing lever and the claw member need to be exactly adapted to one another. Thus, precise adjusting of the apparatus and associated cam plate is necessary.
Accordingly, it is the object of the present invention to provide a wrapping machine in accordance with the preamble of claim 1 which enables rear end folding along a rear vertical edge .of the product being wrapped to be neatly performed while the structure of the swingable claw be considerably simplified.
Accordingly, in order to overcome the drawbacks existing in the art, the present invention presents a wrapping machine, the engaging claw member of which, in forming the vertical rear edge folding, directly engages the sidewardly projecting wrapping paper flap along the folding line at the rear vertical edge of the product.
The swingable claw includes a rigid arm which has an integral support plate extending substantially perpendicularly to said arm and bearing a pivot pin for pivotally supporting said engaging claw member at the rear portion of the claw member with respect to the direction of movement of the product, the free front end of said claw member being urged away from said shaft by a helical spring disposed between the support plate and the free front portion of the engaging claw member such that the same is kept spaced from said support plate in a withdrawn inoperative position of the claw, the degree of opening between said free front end of the claw member and the support plate being adjusted by a setting screw means, disposed opposite to the spring with respect to said pivot pin such that the outer edge of the free front end of the claw member comes into contact with a folding line of the wrapping paper when the claw is swivelled inwardly.
The features and advantages of the present invention will become more apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings, in which

Fig. 1 is a plan view of an embodiment of the present invention;
Figs. 2 to 8 are explanatory views showing a conventional wrapping process; and
Fig. 9 is a sectional view of a support mechanism for wrapping paper.

The conventional wrapping process was initially explained with the aid of Figures 2 to 8. The present invention is hereinafter described in detail referring to an embodiment shown in Fig. 1. As shown in Fig. 1, the rear portion of a swingable claw 12 with regard to the direction of proceeding of a product A to be wrapped is pivotally coupled by a pin 13 to the support plate 11a of a turnable arm 11 secured on a turning shaft 10, and the free front end 12a of the claw 12 is urged in such a direction as to open away from the support plate 11a, by a helical spring 14 provided between the free front end 12a and the support plate 11 a. The degree of opening of the swingable claw 12 from the support plate 11a a is adjusted by a stopper 15 secured on the rear portion of the support plate by a screw.
As shown in Fig. 9, a support mechanism is provided for the pasted upper folded portion P₃ of soft wrapping paper P and an upper guide plate 16 has a vacuum suction port 16a. As a result, paste 17 applied to the upper folded portion P₃ of the paper P is prevented from irregularly clinging to other portions as the paper P is wound as U on the product A.
The turnable arm 11 and the swingable claw 12 are moved between an opened position shown by a full line in Fig. 1 and a closed position shown by a two-dot line therein, respectively. In the closed position, the free end 12a of the swingable claw 12 is closed by the wrapped product A against the helical spring 14.
When the swingable claw 12 is in the closed position and the wrapped product A is pushed out by a pusher, the free end 12a of the swingable claw is pushed down by the wrapped product A against the helical spring 14 and simultaneously performs a front end face folding P_l. When the swingable claw 12 is in the opened position to be closed onto the wrapped product A, the outer edge Q of the free end 12a whose degree of opening is previously adjusted by the stopper 15 takes a locus to come into contact with the folding line P₄' of the folded end face portion P₄ of the wrapping paper P at the rear of the wrapped product A so that the swingable claw 12 is moved to the closed position shown by the two-dot line in Fig. 1, as the claw performs the rear end face folding P₄ of the wrapping paper P and is simultaneously pushed down by the wrapped product A.
Because the rear portion of the swingable claw 12 is pivotally coupled to the support plate 11a of the turnable arm 11 and the free end 12a of the swingable claw is urged by the spring 14 in such a direction as to open and is normally kept at a prescribed degree of opening, the rear end face folding of the soft wrapping paper P on the wrapped product A is neatly performed along the folding line of the paper.

Claims

A wrapping machine having a swingable claw for forming at least one tuck of wrapping paper along at least one vertical side edge of a product to be wrapped, said swingable claw (2) being rotable about a vertical axis by means of a rigid arm (11) extending substantially radially from a shaft (10) establishing the pivot axis of the claw, said arm comprising an outer end portion (11a) for pivotally supporting an adjustable spring biased engaging claw member (12) of the claw for effecting the desired folding operation, characterised in that
said rigid arm (11) has an integral support plate (11a) extending substantially perpendicularly to said arm (11) and bearing a pivot pin (13) for pivotally supporting said engaging claw member (12) at the rear portion of the claw member with respect to the direction of movement of the product, the free front end (12a) of said claw member being urged away from said shaft (10) by a helical spring (14) disposed between the support plate (11 a) and the free front portion (12a) of the engaging claw member (12) such that the same is kept spaced from said support plate (11a) in a withdrawn inoperative position of the claw, the degree of opening between said free front end (12a) of the claw member (12) and the support plate (11a) being adjusted by a setting screw means (15), disposed opposite to the spring (14) with respect to said pivot pin such that the outer edge (Q) of the free front end (12a) of the claw member (12) comes into contact with a folding line (P'₄) of the wrapping paper when the claw is swivelled inwardly.