Release Mechanism

This invention relates to a method of releasing articles from holders mounted on a conveyor traveling continuously at varying speed, the varying ballistic trajectory of the released articles being automatically compensated depending on the speed of the conveyor by shifting the discharge locations of the article holders.

Such a method is known from U.S. Pat. No. 3,224,579 (Scollard), U.S. Pat. No. 4,569,444 (McEvoy) and from Dutch patent application no. 67.06017 (Mosterd). In these publications the ballistic trajectory compensation is realized by moving the releasing means in the direction of transport of the moving conveyor, in a positive or in a negative sense.

A disadvantage of the known methods is that the adjustments of said compensation in the direction of travel of the conveyor -- normally, a plurality of them, for instance twelve or more, are arranged side by side -- will be the same at a given speed. In practice, however, this is not always desirable, since the ballistic trajectory of lighter articles will often be different from that involved in the fall of heavier articles.

The object of the invention is to remove the drawback mentioned.

To that effect, a method of the type described in the opening paragraph hereof is characterized in that one or more adjacent ones of the releasing members for each delivery station are fixedly arranged side by side in the direction of travel of the conveyor. These release members may have an operational range extending in the direction of travel exceeding the horizontal component of the longest ballistic trajectory in question.

The invention further relates to an apparatus for carrying out the above described method, the releasing members having release elements whose stop range in the direction of travel of the conveyor may exceed at least the horizontal component of the longest ballistic trajectory in question.

The release elements of the releasing members may be of oblique or bent design and, for opening the article holder, can be brought into the path of the article holder perpendicularly to the direction of travel of the conveyor, in such a way that the location and time of stopping are in agreement with the corresponding speed of the conveyor.

Further, the releasing means may be solenoids or the like and the release elements may be mounted on the movable armature thereof.

The release elements may also be independent elements which can be successively operated by cams mounted on a central shaft operated by a stepping and/or DC voltage motor.

Further, each releasing means may be a stepping motor and the release element may be mounted on the shaft thereof, which depending on the speed of the conveyor rotates through a given angle and thereby determines the stop location of the article holder.

In yet another embodiment, the releasing means are electromagnets which upon excitation act as release elements to pull a magnetizable element of a passing holder, so that the release of the article is realized.

In that embodiment, the number of electromagnets for each delivery station may exceed by at least one the number of receiving positions at each receiving station.

According to a yet further embodiment of the invention, the releasing means consist of solenoids or the like and the release elements are mounted on the movable armature thereof, the number of release elements exceeding by at least one the number of receiving positions for each receiving station. Thus, the releasing members arranged farthest downstream, corresponding to the number of release elements, can be used at lower speeds of transportation, while the releasing members arranged farthest upstream can be used at higher speeds.

In similar manner as described hereabove, the release elements may be independent levers, which are successively operated by cams mounted on a central shaft operated by a stepping motor or the like, while the number of cams exceeds by at least one the number of receiving positions for each receiving station. In such a construction, too, the cams arranged farthest downstream can be used at lower conveyor speeds and the cams arranged farthest upstream at higher conveyor speeds.

To clarify the invention some embodiments of the release mechanism will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a schematic top plan view of a part of a releasing apparatus according to the invention;

FIG. 2 is a side elevational view of the apparatus according to FIG. 1;

FIG. 3 is an elevation similar to FIG. 2 of a second embodiment of the releasing apparatus according to the invention;

FIG. 4 is an elevation similar to FIG. 1 of a third embodiment of the releasing apparatus according to the invention;

FIG. 5 is an elevation similar to FIGS. 1 and 3 of a fourth embodiment of the apparatus according to the invention;

FIG. 6 is a side elevation of the apparatus according to FIG. 5;

FIG. 7 is an elevation similar to FIGS. 2, 3 and 5 of a fifth embodiment of the apparatus according to the invention; and

FIG. 8 is an elevation similar to FIGS. 1 and 4 of a sixth embodiment of the apparatus according to the invention.

According to FIG. 1 a releasing apparatus comprises a conveyor 3 on which article holders 2 are mounted for transporting articles 1. The article holders can be operated by a release mechanism 4. The release mechanism 4 comprises a mounting frame 8 on which a plurality of releasing members 5 (e.g. electromagnets or the like) are arranged, which can be actuated in the required sequential order of release of articles 1. Mounted on the movable armature of each releasing member 5 is a release element 6 which is an elongated element, which can be brought within the path of the release means 7 of the holders 2, so that the holders 2 are opened and the articles are released. By mounting the release element 6 on the armature of the releasing member at an angle with the direction of travel of the conveyor, the stop location between the release element 6 and the release means 7 is shifted when the releasing member 4, depending on the speed of the conveyor 3, is shifted perpendicularly to the direction of travel of the conveyor 3. This shifting can be realized by means of a drive (not shown), which shifts the mounting frame 8 of the releasing members in the direction of the arrow indicated at 9 in guideways 10, which in the present case extend perpendicularly to the direction of travel of the conveyor 3.

The embodiment according to FIG. 3, of which only the parts that differ from those of the apparatus according to FIGS. 1 and 2 will be discussed, concerns a releasing apparatus in which the armatures of the releasing members 5 are provided with substantially adjacent release elements 11. By delaying or accelerating the actuation of the releasing members depending on the conveyor speed, the moment of impact and hence the release location is shifted. In this embodiment it is also possible that at different speeds of the conveyor 3, different releasing members 5 serve to fill the same receiving position 12 of a receiving station 13. In other words, at a low speed, releasing member 5-1 releases the article from holder 2'-1 through trajectory 14-1, while at a high speed this function is taken over by releasing member 5-2, from holder 2"-2, through trajectory 14-2. In that case, therefore, the number of releasing members must always exceed by one or more the number of receiving positions 12 in receiving station 13.

In the third embodiment, shown in FIG. 4, the releasing members consist of rotating magnets or stepping motors 15, on whose shaft are mounted release elements 16 which depending on the speed of the conveyor 3 can rotate from an inoperative position 17 through a specific angle depending on the speed of the conveyor into the proper releasing position 18 which determines the release location for release means 7 of the holder.

FIGS. 5 and 6 schematically show a fourth embodiment of a releasing system, in which release elements 11 are designed as levers (see the side elevation according to FIG. 6), which can rotate about pivots 20 and can successively be operated by cams 21 on shaft 22, driven by a stepping motor 23. A spring 24 provides for quick and forceful release. By decelerating or accelerating the actuation of the stepping motor depending on the conveyor speed, the moment of release and hence the location of release is shifted.

The release elements 11 are arranged virtually adjacent to each other and, in view of different conveyor speeds, can take over from one another the release function in respect of one receiving position, in the same way as discussed hereinabove with reference to the apparatus according to FIG. 3.

Accordingly, there are always mounted on the cam shaft 22 one or more cams than there are receiving positions 12 in the receiving station 13. Thus, at low speed the left-most lever 25 is blocked by means of magnet 26 and at high speeds the right-most lever 25 by means of a magnet 27.

FIG. 7 shows a fifth embodiment of a releasing apparatus, in which the section 30 mounts a plurality release member in the form of of electromagnets 31, which can be excited in the desired sequential order of release and thereby constitute release elements to attract magnetizable release means 32 of article holder 33, whereby these holders are opened. Here, too, the moment of actuation of the magnets, depending on the conveyor speed, determines the location of release.

As in the apparatuses according to FIGS. 3 and 5, more than one magnet can take over from each other the release function in respect of one receiving position 12 at different speeds, in other words the number of magnets may exceed the number of receiving positions for each receiving station.

FIG. 8 shows a sixth embodiment, in which solenoids are used as releasing members in the same manner as in the embodiment according to FIG. 1. In the apparatus according to FIG. 8 the armature of a solenoid or its extension constitutes a release element which is brought into the path of the release means of the article holders for the purpose of discharge. In this embodiment, the release means on the article holder is an elongated element, shaped like the element 6 of FIG. 1. These release means are are in an oblique position relative to the direction of travel of the conveyor and the solenoids can be moved perpendicularly to the direction of travel of the conveyor, which is indicated in FIG. 8 by a double arrow perpendicular to the direction of travel of the holders.

It will be clear that within the framework of the inventive concept further embodiments are conceivable, including the use of a plurality of conveyors 3 arranged side by side for filling a multi-row receiving station 13.