EP0423115A1

EP0423115A1 - A device for elevating a number of parts from a storage of parts

Info

Publication number: EP0423115A1
Application number: EP19880908403
Authority: EP
Inventors: Berthon SÖDERLING
Original assignee: Arkivator AB
Current assignee: ARKIVATOR AB
Priority date: 1987-09-29
Filing date: 1988-08-19
Publication date: 1991-04-24
Also published as: WO1989002865A1; FI892574A; DK261389D0; SE8703748D0; SE8703748L; SE459002B; DK261389A; FI892574A0

Abstract

A device for elevating a number of parts (11a) from a bulk storage of parts (11) being stored in a container (1) hav ing a top opening edge (2), and for moving said number of parts sidewardly over said opening edge (2) to a feeding path (3) located outside the opening edge. The container (1) houses a storage piston (9) whichsupports said bulk storage of parts (11), and a feeding piston (13) for elevating said number of parts (11a). The number of parts are caused to initially slide sidewardly from the storage piston (9) to the feeding piston (13), and then to be elevated by this, and finally to slide side wardly from the feeding piston (13) to the feeding path (3). The feeding path (3) is rotatably mounted around said opening edge (2) in order to convey said number of parts. The feeding path (3) has orienting plates (18) which allow passage of the parts of said number of parts only if they have a correct orientation, whereas they in another case are forced by the orien ting plates to fall back into the container.

Description

A device for elevating a number of parts from a storage of parts

TECHNICAL FIELD

The present invention relates to a device for elevating a number of parts from a storage of parts which are placed in a container having a top opening edge, and for moving said elevated number of parts sidewardly over said opening edge to a feeding path located outside said opening edge, a first space of the container having a bottom supporting said bulk storage, a second space of the container housing a feeding piston provided with a supporting surface which inclines a predetermined angle downwards, as seen in a di- rection away from said bottom, said feeding piston being movable upwards and downwards like a shuttle between a bot¬ tom position, in which said number of parts can slide by means of gra ity from said bulk storage to the supporting surface of the- feeding piston, and a top position, where said number of parts can slide by means of gravity from the feeding piston to said feeding path.

The device in accordance with the invention is particularly but not exclusively, adapted to be used as a means for feeding parts, the feeding means being capable of fetching parts from an unarranged storage of parts ("bulk storage") and placing t.hem one after the other in a desired orienta¬ tion in a so called fetch position or operation position, where they can be gripped by a robot arm.

BACKGROUND PRIOR ART

A device of the above kind is known from DE-A-3 503 102. That patent illustrates a shuttle co-operating with a storage of parts within a container. The storage has a stationary bottom, which means that the bottom has to be located relatively igh up in the container in order to enable the parts to fall over to the shuttle. Therefore, only a small portion of the container volume can be used as a storage for the parts. Therefore, the container has t be refilled very often. A further serious drawback is that the parts are subjected to wearing against the side wall of the shuttle when this sweeps past the storage of parts du¬ ring its up and down movement.

SUMMARY OF THE INVENTION

The object of the invention is to provide a device of the aforement oned kind, where the above drawbacks are elimina¬ ted. This object is achieved with a device according to the invention having the characterizing features set forth in Claim 1.

Further developments of the invention are set forth in the depending Claims.

In accordance with the invention the device according to the invention is provided with an interior vertical parti¬ tion wall which has a top edge which terminates at a pre¬ determined distance beneath the opening edge of the con¬ tainer , said par tion wall dividing said container into said first and sa d second spaces, said bottom being for- med by a supporting surface of a second piston, said sup¬ porting surface of said second piston being inclined down¬ wards towards said feeding piston, said second piston being movable upwards and downwards in said first space and being capable of delivering said number of parts to the shuttle during its upward movement.

Because the bottom of the container is movable in this man¬ ner, the uppermost number of parts of the storage will al¬ ways be located at such a suitable height above the shutt¬ le - when this is in its lowermost position - that the number of parts can slide over to the shuttle. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in further detail with re¬ ference to the accompanying drawings, in which Figs. 1 - 3 show three consecutive function steps of feeding means according to the invention. Fig. 1A is an end view as seen from above of the feeding means of Figs. 1 - 3. Fig. 4 is a perspective view of a preferred embodiment according to the invention. Fig. 5 is, on a larger scale, a longitudi- nal section of the feeding means according to Fig. 4.

DESCRIPTION OF A PREFERRED EMBODIMENT

Figs. 1-3 illustrate schematically the function of a device according to the invention, here shown in the form of a feeder for fetching parts from a storage and transferring them to a feeding path. The feeder includes a cylindrical vertically oriented container 1 having a top opening, the circular opening edge 2 of which is concentrically surroun- ded by the feeding path^' 3 in the form of a ring which is oriented horizontally around the opening edge 2, the flat top surface of the ring forming a supporting surface for the parts, the ring 3 being arranged to be rotated in any desired direction around the longitudinal axis 4 of the container by drive means, not shown.

The container 1 has an interior, vertical, flat partition wall 5, which has a . horizontal top edge 6 that terminates at a predetermined distance d.. beneath the opening edge 2 of the container. The partition wall 5 thereby divides the container 1 into two spaces 7 and 8, of which the space 7 houses a storage piston 9 wh ch has a cross-section in the form of a circle segment and which has a flat supporting sur¬ face 10 which supports a bulk storage 11 of parts or artic- les having mutually like shape. The parts or articles may for instance consist of sleeves having a T-shaped longitu¬ dinal section of the kind shown in Fig. 4. The supporting surface 10 inclines downwards, as seen in the direction to¬ wards the partition wall 5, with an angle v.. that should be greater than 10 .

The space 7 is filled with the parts 11 up to a limit level 12, which is located at a predetermined distance d above the end edge 6 of the partition wall. The limit level 12 is detected by a couple of photocells 12a, which are sche¬ matically depicted in Fig. 5.

The other space 8 houses a feeding piston 13 having a cross- section in the form of a circle segment and having a flat supporting surface 14, which inclines a predetermined angle v-,, which is greater or equal to 5 , downwards, as seen away from the partition wall, and which is arranged to ele¬ vate a number of parts 11a from the bulk storage 11. The feeding piston 13 is thereby arranged - by means of a dri¬ ving means not shown - to move upwards and downwards Like a shuttle between a bottom position (Fig-. 2) - in which the supporting surface 14 of the feeding piston is Located at such a predetermined distance beneath the Limit Level 12 that the number of parts 11a can slide sidewardly by means of gravity over the edge 6 to the supporting surface of the feeding piston - and a top position (Fig. 3), in which the feeding piston with a vertical side surface 15 thereof forms an upwardly projecting extension of the partition wall 5, and in which position the number of parts 11a can slide sidewardly by means of gravity from the supporting surface 14 to the feeding path 3.

The space 8 has in its bottom a stop means 16, against which the feeding piston 13 is able to abut at the end of its downwardly directed movement.

The storage piston 9 is arranged - by means of drive means not shown - to move upwards from a bottom position (Fig. 2) to a plurality of successive upper positions, one of which is shown in Fig. 3. In all of these positions the top level of the bulk storage corresponds to said limit level 12. The uppermost position of the feeding piston is shown in a dotted line 17 in Fig. 2. The circle segment sections of the pistons 9 and 13 also give the supporting surfaces 10 and 14 a corresponding circle segment shape, as is shown in Fig. 1A. The supporting surface 14 has an area which is substantially less than the supporting surface 10. The cross-section segment of the piston 13 has suit¬ ably a segment height which is less or equal to one third of the segment height of the cross-section segment of the piston 9.

The function of the feeder is

In the start position shown in Fig. 1, where the feeding piston 13 is in its top position, where it with its side surface 15 forms an upwardly pro ecting extension of the partition wall 5, the parts are placed in the space 7 to form said bulk storage 11 up to the limit level 12. The feeder is now started by driving the feeding piston 13 downwards to the bottom position shown in Fig. 2, where it abuts the stop means 16, which thereby generates a vibratory "shock" wave which travels up to the bulk stor- age 11, such that the upper portion of this, constituting the aforementioned number of parts 11a, is caused to slide by means of gravity over to the supporting surface 14 of the feeding piston. However, the stop means 16 is not necessary for the function of the feeder, since it has turned out that the number of parts 11a will automatically start to slide by means of gravity due to the stirring effect that is achieved in the number of parts 11a, when the side surface 15 of the feeding piston scrapes against the number of parts 11a during its downwardly directed movement, such that the number of parts 11a will slide as soon as the piston 13 will reach beneath the limit level 12, or in any case beneath the edge 6 of the partition wall. The storage piston 9 will then elevate the bulk stor age 11 until the couple of photocells 12a will detect the limit 12 and stop the piston 9. When the piston 9 stops, the feeding piston 13 will start its movement upwards there by conveying the number of parts 11a to their uppermost po¬ sition, shown in Fig. 1, where the number of parts 11a will be Located above the opening edge 2 such that they will slide by means of gravity over the edge 2 to the feeding path 3. Thereafter, the feeding piston 13 will again descend to its Lowermost position, shown in Fig. 2, in oi— der to fetch a further number of parts 11a, this cycle being repeated as long as there are any parts left in the bulk storage 11.

A practical embodiment of the feeder according to Figs.^" 1-3 is shown in perspective in Fig. 4, and on a Larger scale in a Longitudinal section in Fig 5. The same reference nume¬ rals are used in the practical embodiment of Figs. 4-5 as have been used in the schematical function drafts of Figs. 1-3.

The feeding path 3 is shown in Fig. 4 together with a gui¬ dance means in the shape of a curved orienting plate 18, which is being held at an adjustable distance above the feeding path 3 and at an adjustable, desired distance from the opening edge 2 of the container 1, by means of a number of holding means 19, which are adjustably supported by a cylindrical sleeve 20,^" which is rotatably journalled and adjustable in a desired rotational angle around a cylindri- cal outer casing 21, which coaxially surrounds the contai¬ ner 1, as is best seen in Fig. 5.

The sleeve 20 has an opening 22, from which an inclined flute 24 extends, which is controlled by a couple of photo- cells 23. Thereby, the distance that the parts have to travel along the feeding path 3 to the flute 24 may be adjusted by rotating the sleeve 20. Fig. 4 shows how the parts 11a slide from the supporting surface 14 of the feeding piston to the feeding path 3, and how the parts thereafter - whi le the feeding path is being rotated at a speed of about 0-20 revolutions per minute - will be forced outwards against the orientation plate 18, which is adjustaed to allow the passage of the parts only if they have a predetermined orientation, whereas they in other case, as is shown at 11 ', ill fall back down into the container 1. Those parts having the desired orientatio will finally reach the flute 24, where they slide to a pre¬ determined position, for instance a so called fetch positio or an operation position for a robot arm, not shown.

Fig. 5 shows further details of the feeder, such as drive means 25 for the storage piston 9, and a co-operating ball screw 26 and nut 27. Also shown is drive means 28 with a programme chart 29 for the operation of a shaft 30 which drives two wheels 31a, b, which in turn drive a drive disc 32 which rotates the feeding path 3. Fig. 5 also shows drive means 33 which operates a connecting-rod 34 which is operatively connected to the piston 13, and arranged to drive a link arm 35 in an up and down movement n order to accomplish the shuttle movement of the piston 13.

A protection tube 36 is located above the screw 26 and follows the storage piston 9 when this moves, such that the tube 36 may serve as a level indicator. Thereby, an operator may, also if he is far away from the device, be able to estimate how many parts that are still left on the piston 9.

Claims

C la i ms :

1. A device for elevating a number of parts (11a) from a storage of parts (11) which are placed in a container (1) having a top opening edge (2), and for moving said eleva¬ ted number of parts sidewardly over said opening edge to a ^"feeding path (3) located outside said opening edge, a first space (7) of the container having a bottom (10) supporting said bulk storage, a second space (8) of the container housing a feeding piston (13) provided with a supporting surface (14) which inclines a predetermined angle (v-) downwards, as seen in a direction away from said bottom (10), said feeding piston being movable up¬ wards and downwards Like a shuttle between a bottom posi- tion, in which said number of parts (11a) can slide by means of gravity from said bulk storage (11) to the sup¬ porting surface (14) of the feeding piston, and a top position, where said number of parts can slide by means of gravity from said feeding piston to said feeding path, c h a r a c t e r i z e d in that sa d container (1) has an interior vertical partition wall (5) which has a top edge (6) which terminates at a predetermined distance (d,.) beneath said opening edge (2) of the container, said parti¬ tion wall dividing said container into said first and said second spaces (7, 8), said bottom (10) being formed by a supporting surface of a second piston (9), said supporting surface of said second piston being inclined downwards towards said feeding piston (13), said second piston being movable upwards and downwards in said first space (7) and being capable of delivering said number of parts to said shuttle during the upwards movement of said second piston.

2. A device in accordance with Claim 1, c h a r a c t e - r i z e d in that said bottom (10) of the container is con nected to a level indicator (36) which is capable of suc¬ cessively protruding above said opening edge (2) in respons to said movement of said bottom (10).

3. A device in accordance with any of the Claims 1-2, c h a r a c t e r i z e d in that said angle (v₂) is greater than or equal to 5

4. A device according to any of the Claims 1-3, wherein the parts of said bulk storage (11) have mutually identi¬ cal shape, c h a r a c t e r i z e d in that the con¬ tainer (1) has a cylindrical shape which is open at the top, the feeding path (3) being in the shape of a top sur face of a flat ring that is oriented horizontally around the external side of said opening edge (2) , the ring be¬ ing rotatably mounted around the longitudinal axis (4) of said cylindrical shape in order to convey said number of parts, the feeding path having guidance means (18), which enables said parts to pass only if they have a predeter¬ mined orientation, whereas the guidance means in other cas will cause the parts to fall back over the opening edge and down into the container.