Patent Application
20090110534
1. Field of the Invention
The present invention relates to a bag supply apparatus for supplying bags to a conveyer for transporting a bag bundle stacked in such a format that the upper level bag is shifted in a forward direction and more specifically to a bag supply apparatus that supplies bags to a belt conveyor of a conveyer magazine type bag supply apparatus.
2. Description of the Related Art
A bag supply apparatus of the type described above is disclosed in, for instance, Japanese Patent Application Laid-Open (Kokai) Nos. 8-337217 and 2004-210473.
In Japanese Patent Application Laid-Open (Kokai) No. 8-337217, a bag bundle (a group of bags stacked in a manner that the upper level bag is shifted in a forward direction with respect to the conveying direction of the belt conveyor of the bag supply apparatus) transported on the belt conveyor of a conveyer magazine type bag supply apparatus is transported forward; and when the bag bundle has passed a prescribed point, a push-up rods disposed below the belt conveyor is moved upward and lifts up the rear edge of the bag bundle (
In Japanese Patent Application Laid-Open (Kokai) No. 2004-210473, a bag bundle (a group of bags stacked in a such format that an upper level bag is shifted in a forward direction) transported on a belt conveyor of a conveyer magazine type bag supply apparatus is transported forward; and when the bag bundle has passed a prescribed point, a push-up rods disposed below the belt conveyor is moved upward and then a support arms disposed above the belt conveyor rotates to lift up the rear edge of the bag bundle from the rear (
The apparatuses disclosed in Japanese Patent Application Laid-Open (Kokai) No. 8-337217 have problems. In the bag supply apparatus that uses the push-up rods, the push-up rods interferes with the pushing-in motion of the replenishing bag bundle; while in the bag supply apparatus that uses the pull-up rods, a complicated operation is involved for the pull-up rods that make a drive mechanism thereof more complicated as well. In addition, in the bag supply apparatus of Japanese Patent Application Laid-Open (Kokai) No. 2004-210473, a 3-step operation is required to raise the rear edge of the bag bundle; and in the system that uses the push-up rods and the support arms makes the apparatus more complicated, while in the system that uses just the support arms, the actuation mechanism is more complicated. Furthermore, the apparatuses in the above-described two related arts both involve reciprocating actions; and thus, these apparatuses are not suited for high-speed operation and unavoidably generate vibrations and noise when stopped.
Furthermore, in the apparatuses of the above-described two related arts, since a stacked bag bundle (a group of bags simply layered top to bottom) is fed onto the belt conveyor of the conveyer magazine type bag supply apparatus, the upper level bag needs to be arranged by hand on the belt conveyor so that it is shifted in a forward direction. On the other hand, there is such a strong demand for a conveyer magazine type bag supply apparatus that the bag bundle is automatically formed in such a format as described above with at a predetermined pitch (interval) on the belt conveyor; as a result, such attempts have been made that one bag is fed at a time at a predetermined pitch (time interval) for that purpose. In that instance, the pulling-up or pushing-down processing capability for the bag bundle needs to be improved further compared to a case that feeds a stacked bag bundle. However, the processing capability in the apparatuses described in the above-described two related arts, Japanese Patent Application Laid-Open (Kokai) Nos. 8-337217 and 2004-210473 is inadequate.
The present invention was made in view of these problems in the conventional techniques, and an object of the present invention is to provide a bag supply apparatus (especially a bag lifting device) that does not interfere with the feeding of replenishing bags or bundles of bags onto the belt conveyor, that is simple in operation and actuation mechanisms, that reduces occurrence of vibrations and noise, and that has high processing capability.
The above object is accomplished by a unique structure of the present invention for a bag supply apparatus that supplies bags onto a conveyer for transporting a bag bundle stacked in such a format that an upper level bag of the stacked bags is shifted forward, and in the present invention, the bag supply apparatus comprises:
In this structure, the conveyer, for instance, intermittently operates at a set conveying distance (feed pitch); and in this case, the feed pitch is the shifting amount (pitch) between the bags that form the bag bundle on the conveyer. When the conveyer is operated intermittently, it is preferable to set a timing so that the bag lifting device lift the bag bundle and the bag feeding device feed bags when the conveyer be halted. However, in the present invention, the conveyer can be a continuously rotating type.
In the bag lifting device of the bag supply apparatus of the present invention, the time required for a single rotation which the pair of bag supporting portions make is maintained essentially constant; however, in the present invention, even if the rotation speed for a single rotation (rotational angle per unit of time) is constant, it can be so set up so that the rotation speed changes during the single rotation. In the latter instance, the rotation speed in a prescribed rotational angular range of the support elements in which the pair of support elements are supporting and lifting up the rear edge of the bag bundle on the conveyance surface of the conveyer should preferably be set slower on average than the rotation speed in the remaining rotational angular range. The angular range during which the bag supporting portions are lifting the rear edge of the bag bundle from the conveyance surface cannot be enlarged excessively; however, by way of slowing down the rotational speed in relative terms within the rotational range, it is possible to increase the time during which the bag supporting portions have the rear edge of the bag bundle lifted up from the conveyance surface and make better use of the time during which bags are fed from the bag feeding device. This setup is particularly valuable when the processing capability (number of bags supplied to a packaging machine per unit of time) of the conveyer and of the bag supply apparatus is high. More specifically, it is, in the present invention, possible to set a slower rotational speed for a part of the angular range (especially for the angular range enabling an interval during which bags can be inserted without interference between the rear edge of the bag bundle and the conveyance surface of the conveyer) or for all of the angular range, and it is further possible to temporarily stop the rotation (in other words, imparting intermittent rotation) within such an angular range.
In one example of a specific embodiment of the above-described bag lifting device, as a part of the rotation mechanism, the bag lifting device is comprised of, as a part of the rotation mechanism, a pair of rotation transmission members that make a translational motion of the same rotational radius and rotational direction as each one of the bag support members on a plane perpendicular to the conveyance direction, and the bag support members are respectively provided on the rotation transmission members.
More precisely, this bag lifting device includes a rotation transmission member (“a first rotation transmission member”) that imparts translational movement that has the same rotational radius and rotational direction as that of one of the pair of (two) bag supporting portions, and another rotation transmission member (“a second rotation transmission member”) that imparts translational movement that has the same rotational radius and rotational direction as that of another one of the pair of (two) bag supporting portions; and one of the bag support members is provided on the first rotation transmission member, and the other bag support member is provided on the second rotation transmission member. The first and second rotation transmission members make a symmetric rotational movements so that these rotation transmittal members rotate in opposite directions from each other. The translational motion during the rotation of each one of the rotation transmission members is transmitted to the bag supporting portion via each bag support member, and the bag supporting portion makes translational motion of rotation while maintaining a horizontal attitude.
The rotation mechanism of the bag lifting device is, as a more specific embodiment, comprised of a total of four crank mechanisms in which two of the crank mechanisms are provided for each one of the rotation transmission members, and it is further comprised of a drive power source for operating the rotating the crank mechanisms. In this structure, the crank shaft of the two crank mechanisms linked to the respective rotation transmission members are provided at the same height and with a horizontal spacing in between, and they are provided in parallel with respect to the conveyance direction of the conveyer and rotated synchronously in the same direction. The crank arms of the crank mechanisms have the same length (between the crank shaft and the crank pin) and are mutually parallel, and the rotation transmission members are linked to the respective crank pins of the crank mechanisms. As a result, a type of parallel link mechanism is constituted by the rotation transmission member and the two crank arms; and by the rotations of the crank shaft, the rotation transmission member imparts the translational motion of rotation.
Furthermore, the bag supply apparatus of the present invention can, for example, be a multiple-component bag supply apparatus in which the conveyer is provided in a plurality of numbers in parallel, the pair of bag support members are provided for each one of the conveyers, and the bag feeding device is provided at the rear of each one of the conveyers. In this structure, the rotation transmission members are provided in a pair, and a plurality of bag support members are provided on each one of the rotation transmission members and make a translational motion synchronously.
In addition, the bag feeding device of the bag supply apparatus of the present invention is comprised, for example, of a bag supporting platform., which has a conveyance surface on its upper surface, and feed pins, which protrude upward from the conveyance surface and make a contact with the rear edge of the bag on the conveyance surface of the bag supporting platform to transport the bag forward. The feed pins are raised and lowered and also moved forward and backward; and it is preferable that when raised, the feed pins protrude from the conveyance surface of the bag supporting platform and moved forward in a protruding state, and then the pins are lowered and moved backward.
The bag feeding device can be comprised of a belt conveyor; however, any conveyer system utilizing this type of feed pins can accurately set the feed-in location.
In addition, in the bag supply apparatus of the present invention, the new bag that is fed by the bag feeding device is a single bag; however, a bag bundle formed by a stack of a plurality of bags can be handled as well.
As seen from the above, in the present invention, the rear edge of a bag bundle (or a single bag) on a conveyer is supported and lifted-up at its left and right sides by the bag supporting portions that are, respectively, continuously rotated or intermittently rotated in the same direction (in other words, without making reciprocating rotations or reciprocating movements) while maintaining the horizontal attitude. Accordingly, the motion of the bag supporting portions and the actuation mechanism therefor can be simple and smooth, the occurrence of vibration and noise can be reduced; and as a result, the bag supply apparatus of the present invention has high processing capability (with shortened time period for lifting up the bag(s) per incidence). In addition, since the bag supporting portions are provided so as to protrude in a horizontally inward direction from the left and right sides of the conveyer, the bag support members do not interfere with the feeding action of the bags, which is done while the rear edge of the bag bundle on the conveyer is being lifted up, onto the conveyer from the bag feeding device.
Furthermore, since the processing capability of the bag lifting device can be enhanced, the rear edges of bundles of bags on the conveyer can be lifted just as quickly as when the bags are fed to the conveyer one after another at a rapid pitch. As a result, the bundles of bags can be stacked automatically in such a format that an upper level bag on the conveyer is shifted in a forward direction, and the pitch (shift amount of the bags) can be kept constant.
A bag supply apparatus according to the present invention will be described below in detail with reference to the accompanying drawings for
As shown in
Each one of the belt conveyors 1 is comprised of a front-side pulley (or a drive pulley), which are not shown in the drawings, a rear-side pulley 5 (a driven pulley), and three (3) belts (round or endless belts) installed between these two pulleys. The belt conveyor 1 makes an intermittent rotation to convey forward a bag bundle (a group of bags) 7 fed onto the conveyance surface (which is comprised of surfaces of the pulley and belt).
The bag bundle 7 is formed by a plurality of bags 7a stacked in such a format that an upper level bag is shifted forward (with respect to the conveying direction of the conveyers) at a constant pitch. More specifically, the conveying distance (feed pitch) in a single intermittent rotation of the belt conveyor 1 makes differential (shifted) amount (pitch) between each one of the bags 7a that form the bag bundle 7. In other words, if the feed pitch of the belt conveyor 1 is changed, the pitch of the bags 7a on the conveyance surface is changed accordingly.
The base platform 4 is provided with a frame 8 that is located under the belt conveyors 1; and on this frame 8, pulley supports 11 for supporting an pulley shaft 9 of the pulleys 5, belt support plates 12 for supporting the belts 6 from below, and guide plates 13 for guiding two side edges of the bag bundle 7 (and the bags 7a) are provided.
The width of the conveyance element (comprised of the pulley 5 and the belts 6) of the belt conveyor 1 is narrower than the width of the bags (or the width of the bag bundle 7), so that the bag bundle 7 (or a single bag) can be lifted or raised without mutual interference between the belt conveyor 1 and the bag lifting device 7.
Four bag feeding devices 3 are provided on the base platform 4. The bag feeding device 3 is comprised of a frame 14 provided on the base platform 4, feed pins 15, drive mechanism 16 for the feed pins 15, and guide plates 17. The guide plates 17 are secured to the frame 14, and they support both side edges of the bag 7a. More specifically, two feed pins 15 and two guide plates 17 are provided for each one of the four bag feeding devices 3. The drive mechanism 16 is provided to drive all four bag feeding devices 3.
The upper surface of a section on the frame 14 which is surrounded by the two guide plates 17 (a bag supporting platform 18) forms a conveyance surface of the bag feeding device 3 for the bag 7a. The height of this conveyance surface of each one of four bag supporting platforms 18 is set so as to be about the same height as that of the conveyance surface of the corresponding belt conveyor 1. Each bag supporting platform 18 is plate-shaped, and a pair of left and right side parallel grooves 19 are formed therein so that a pair of feed pins 15 can protrude therethrough and are moved forward (toward the belt conveyor 1) and backward (toward the bottom end with respect to
The drive mechanism 16 of bag feeding device 3 is comprised of a raising/lowering mechanism for raising and lowering the feed pins 15 and a moving mechanism for moving the pins 15 in forward and backward directions.
The raising/lowering mechanism of the drive mechanism 16 is, as best seen from
The moving mechanism of the drive mechanism 16 is constituted by, as seen from
The bag transfer member 32, which is provided in association with the bag feeding device 3, is, as best seen from
Each one of the bag lifting devices 2 of the bag supply apparatus is, as seen from
The bag support members 35 and 36 are provided at a proximity of the rear edge of each belt conveyor 1, in other words, on the left and right sides of the pulley 5 in the shown structure (see
The rotation mechanism 37 of bag lifting device 2 is comprised of two rotation transmission members 38 and 39 (see
As seen from
As seen from
The rotational angle settings for the respective crank mechanisms 41-44 are rendered so that the orientation of the crank arms 41c and 42c (or the position of the crank pins 41b and 42b in relation to the crank shafts 41a and 42a) comes to a symmetrical position in relation to the orientation of the crank arms 43c and 44c (or the position of the crank pins 43b and 44b in relation to the crank shafts 43a and 44a).
In operation in the construction described above, when the crank shafts 41a and 42a are rotated rightward in
The translational motion of rotation of each of the rotation transmission members 38 (that has the bag support members 35) and 39 (that has the bag support members 36) is transmitted to each of the bag supporting portions 35a and 36a via each bag support member 35 and 36, and, as shown in
More specifically,
The rotational center (which is just below the conveyance surface of the belt conveyor 1 and just outside both side edges of the bag bundle 7) and the rotational radius are set so that when the bag supporting portions 35a and 36a are being raised (or in the upward stroke), the bag supporting portions 35a and 36a move inwardly and come into contact from below with the two side edges of the bag bundle 7 (the side edges being the areas protruding from the belt conveyor 1 on the right and left sides), thus supporting the rear edge of the bag bundle 7 and then move outwardly and disengage from the two side edges of the bag bundle 7. This rotational track of the bag supporting portions 35a and 36a must be set so that the bag supporting portions 35a and 36a do not contact the conveyance element (the pulley 5 and the belt 6) of the belt conveyor 1 and that the gap between the upright portions 35b and 36b of the bag supporting portions 35 and 36 is not narrower than the width of the bags.
In
The thickness of the bag supporting portions 35a and 36a that are for supporting the bag bundle 7 needs to be considered in relation to the gap described above. However, since only a single bag is fed, and since the thickness of the bag supporting portions 35a and 36a can be reduced, the thickness of the bag supporting portions 35a and 36a does cause any significant problem.
Overall operational timing in the bag supply apparatus according to the present invention is, for example, as follows:
(1) In the bag feeding device 3, the bag transfer member 32 (see
Then, the air cylinder 24 is activated to raise the feed pins 15 so that the pins protrude upward from the conveyance surface of the bag supporting platform 18. Needless to say, the position at which the feed pins 15 protrude is behind the bag 7a placed on the bag supporting platform 18.
Next, the drive power source (not shown) advances the slide member 27 forward (or upward in
The bag transfer member 32 then returns to a vertical position and suction-holds the next bag.
(2) In the bag lifting device 2, the servo motor (not shown) is being activated so that the bag supporting portions 35a and 36a are continuously making translational motion of rotation. With the same timing as when the feed pins 15 push the bag 7a forward into the bag feeding device 3, the bag supporting portions 35a and 36a make contact with and raise the rear edge of the bag bundle 7 mounted on the conveyance surface of the belt conveyor 1, forming a gap between the conveyance surface and the bag bundle 7. The bag 7a that was pushed forward by the feed pins 15 is fed into the gap and to a prescribed position (a position separated to the rear by a constant pitch from the bag at the very end to that point) on the conveyance surface of the belt conveyor 1.
(3) The belt conveyor 1 stops when the bag supporting portions 35a and 36a make contact with the rear edge of the bag bundle 7 mounted on the conveyance surface of the belt conveyor 1 and lift up the bag bundle 7. The feed pins 15 feed the bag 7a in the interval during which the belt conveyor 1 is stopped.
After the new bag 7a is supplied, the belt conveyor 1 is intermittently operated for one pitch, and the feed pins 15 that fed the bag 7a immediately are moved down and then moved rearward.
The above operation is made with reference to all of the four belt conveyors 1 simultaneously; however, such can be made for selected one or plurality of conveyers as well.
The foregoing example represents one embodiment of the present invention, and a variety of alterations are possible. For example, a conveyance means (conveyer) can be used instead of the belt conveyor 1, the belt conveyor 1 can be continuously operated, and the bag supporting portions 35a and 36a of the bag supporting portions 35 and 36 can be of a rod-shaped instead of plates. Furthermore, it is possible to alter the rotation speed of the bag supporting portions 35a and 36a while it is in operation, and the bag supporting portions 35a and 36a can be rotated intermittently. In addition, the bag feeding device 3 can be substituted by another feeding means such as a belt conveyor, and the bag feeding device 3 can feed a bag bundle instead of single bags.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-277191 | Oct 2007 | JP | national |
