GB2220649A

GB2220649A - Dispenser for flat pack electronic clips

Info

Publication number: GB2220649A
Application number: GB8818117A
Authority: GB
Inventors: Anthony C Latham
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-07-29
Filing date: 1988-07-29
Publication date: 1990-01-17
Anticipated expiration: 2008-07-29
Also published as: GB2220649B; GB8818117D0

Abstract

A device for automatically presenting electronic chips at a presenting station P comprises a track 12 and pusher blade 17 with a leading edge for pushing chips one at a time from a dispensing station D along the track 12. Chips are held at the dispensing station D in a stack face to face in a magazine 13, the lowermost chip in the stack resting on the track 12. Reciprocation of the blade 17 drives the chips from the base of the stack, one at a time. Sensors (infra-red) monitor correct performance of the device. The narrowness of the track permits location of the presenting station P in constricted locations around robot assembly devices. <IMAGE>

Description

ASSEMBLY METHOD AND APPARATUS A multitude of mass produced product items consist of a large number of electronic components fitted to a printed circuit board. Passive components are often fitted to the board automatically, using computer-controlled assembly machines.

Increasingly, this sort of product item includes at least one flat pack integrated circuit chip. These chips are of high value and require delicate handling.

For these reasons their incorporation in the product item has frequently been achieved through the agency of human assembly line operatives. It has, however, been proposed to build in to the assembly machine a device for dispensing chips from a magazine to a presenting station, for automatic assembly into the product item.

There is an increasing need to make available to existing assembly machines the facility to assemble, automatically, product items which include one or more flat pack chips. What is required is a device for presenting chips at a presenting station, which device may be added to a range of existing assembly machines.

According to a first aspect of the present invention there is provided a method of mass production of a product item assembled from components which include a flat pack integrated -; rcuit chip, which method is characterized by the steps of: 1. providing a magazine which contains a stack of the flat pack chips arranged face to face; 2. locating an open end of the magazine at a dispensing station with the magazine arranged transverse to a delivery track which connects the dispensing station to a presenting station; and 3. causing a pusher blade to reciprocate lengthwise within the delivery track, across the end of; the magazine, to drive the chips, at a rate of one per revolution, from the dispensing station to the presenting station.

According to a second aspect of the present invention there is provided apparatus for the mass production of a product item assembled from components which include a flat pack integrated circuit chip, which apparatus is characterized by; 1. a feed channel which extends from a dispensing station to a presenting station and which includes a flat support surface; 2. a pusher blade in the channel above the base surface and driven to reciprocate through the dispensing station lengthwise along the channel by an actuator; 3. the pusher blade having a leading edge which moves during said reciprocation between a retracted position in the channel adjacent the dispensing station and an extended position adjacent the presenting station;; 4. a magazine which cooperates at one open end thereof with the channel at the dispensing station, for containing a stack of said circuit chips backed up from the open end transversely away from the channel and urged towards the channel, whereby movement of the blade from its retracted to its extended disposition drives from the stack the circuit chip in the channel and on the end of the stack, and conveys said chip from the dispensing station to the presenting station; and 5. electronic logic circuitry to control the operation of the actuator.

By use of a thin blade and narrow delivering track, the dimensions of the device transverse to the track at the presenting station may be made extremely compact. In this way, the presenting station can be provided at a location close to the point of assembly of the product items without interfering with other parts of the assembly machine. Furthermore, such compactness increases the range of possibilities for using the device with existing assembly machines.

Preferably, sensors at the presenting station detect the presence or absence of a product item at the presenting station, and provide such information to the logic circuitry. These sensors can be infra red sensors, with corresponding sources of one or more beams of infra red radiation.

Preferably, the logic circuitry causes the reciprocation cycle to repeat only when at least a predetermined minimu time has elapsed since the product item is drawn from tne presenting station.

Preferably a sensor is provided to detect the presence of the pusher blade at its retracted disposition, and the logic circuitry inhibits the commencement of a further cycle until the pusher blade is so detected.

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: FIGURE 1 is a perspective view of an embodiment of apparatus according to the invention; FIGURE 2 is a similar view of a fragment of the apparatus, drawn to a larger scale; and FIGURE 3 is a block diagram of the logic circuitry.

Referring to Figure 1, the device comprises a pair of structural plates 10 and 11 which depend from the two long sides of a track 12 which extends through a dispensing station D to a presenting station P at one extreme end of the mounting plates 10 and 11. Above the track 12 at the dispensing station D is a magazine 13, the construction and operation of which is explained below, with reference to Figure 2. The track 12 has a base surface 14 and undercut side walls 15 and 16, and a pusher blade 17 is able to slide lengthways in the track 12, above the base surface 14 and confined between the undercut side walls 15 and 16. The blade 17 is driven to reciprocate within the track 12 by a double-acting pneumatic actuator 18 which is housed between the plates 10 and 11.The blade 17 has a leading edge 21 (visible in Figure 2) which, in a retracted position of the slide 17, as shown in Figure 2, is on the side of the dispensing station D remote from the presenting station P. At the other extreme of the reciprocatory movement of the slide 17, the leading edge 21 is adjacent the presenting station P.

Referring now to Figure 2, the wall structure of the track can be seen in more detail. Flanking the pusher blade 17 is a pair of guide bars 22 and 23 which provide the vertical wall surfaces of the track. To the top surfaces of the guide bars are secured a pair of slide retainer strips 24 and 25 which extend inwardly on the track above the guide bars to overlie the pusher blade 17 and retain it against the base surface 14. The retainer strips 24 and 25 stop short of the presenting station P, so as not to prevent removal of circuit chips from the track at the presenting station P. The retainer strips also stop short of the dispensing station D.

Indeed, they stop some way short of the station in order that a fresh magazine may be installed at the dispensing station D as follows. Not shown is an acrylic plastics sheet which overlies the retainer strips 24 and 25 to cover the track 12 except at the dispensing station D and presenting station P.

The dispensing station D is marked by a pair of magazine locating brackets 30 and 31, with each bracket extending upwardly from the guide bars 22 or 23 to a flange which extends inwardly towards the centre of the track. Each of the two ends of the magazine has a pair of shoulders 34 over which may slide a pair of channels 35 of an end cap 36 of the magazine. The magazine may be installed at the dispensing station by placing one of these end caps on the pair of slide bars 22 and 23, adjacent the brackets 30 and 31, so that the end cap 36 presses against the ends of the brackets 30 and 31. In this disposition, the magazine 13 itself is urged lengthwise of the track 14, so that the shoulders 34 slide from the end cap 36 into the receiving grip of the brackets 30 and 31.Each bracket has a stop pin 37 to terminate the sliding movement of the magazine 13 when it is fully engaged with the brackets. This engagement releases the end cap 36 which can then by removed from the guide bars 22 and 23.

Between the plates 10 and 11 is located logic circuitry which is described below with reference to Figure 3.

Figure 1 shows a source 40 and sensor 41 of infra red radiation at the presenting station P, the beam from the source to the sensor being broken at all times when a circuit chip is present at the presenting station P.

Figure 2 shows a further source 42 and sensor 43 of infra red radiation at the dispensing station, the beam from the source to the sensor being interrupted at all times except when the leading edge 21 of the pusher blade 17 is in the fully retracted disposition shown in Figure 2.

Referring now to Figure 3, the circuitry comprises an amplifier 50 of a signal which is positive when both of the sensors 43 and 41 are receiving infra red radiation, that is, when the previous chip has been cleared from the presenting station, and the pusher blade 17 is in its fully retracted disposition. On receipt of this positive signal, the amplifier produces a positive output 51 which provides the input to an adjustable delay timer 52. After a prescribed delay period, the timer produces an output 53 which serves as input to a further amplifier 54 which, in turn, provides as its output 55 the input to a full cycle timer circuit 56 for controlling, via a transistor switch 57, the operation of a 5-port solenoid valve 58 which itself controls the operation of the pneumatic actuator 18.The circuitry also includes a regulated power supply 59 which feeds the amplifier 50 and the valve 58.

In operation of the illustrated equipment, the device is mounted adjacent an assembly system, so that flat pack circuit chips presented at the station P may be taken and used by the assembly system. The circuitry controlling the operation of the illustrated device may be linked with the control logic of the assembly system as a whole, in order that its operation may be coordinated with it.

A stack of the required flat pack chip is charged into the magazine 13, and contained therein by the use of a pair of the end caps 36. Successive charged magazines can be installed at the dispensing station D by the technique described above with reference to Figure 2, which in fact shows in chain dotted outline an intermediate position of the magazine 13 as it moves into the dispensing station from its adjacent, end-capped disposition.

With the pusher blade 17 in its fully retracted Figure 2 disposition, the lowermost chip in the magazine 13 rests on the base surface 14 of the track, pushed down by the entire stack of chips above it. Movement of the pusher blade 17 towards the presenting station P brings the leading edge 21 of the pusher blade 17 into contact with one edge of the lowermost chip and drives the chip from the stack along the track 12 as far as the presenting station P. During this progress, the remaining stack of chips rests on the top surface of the pusher blade 17 but is contained by the walls of the magazine 13 because the gap between the base of the magazine 13 and the base surface 14 is less than the width of two of the chips in the magazine.

As the leading edge 21 of the blade 17 returns to its fully retracted disposition, the stack of the chips in the magazine 13 drops downwardly by the thickness of the blade 17, and the cycle is then repeated until there are no more chips left in the magazine 13.

Obviously, the dimensions of the magazine 13, blade 17 and track 12 are selected to correspond with the dimensions of the chip required to be assembled. It is not difficult to install alternative track and magazine components to cope with different chip dimensions#. The leading edge 21 of the blade 17 may be chamfered, or of any other shape necessary to avoid damage to the chips Some chips have terminals on all four sides, so the leading edge should press against the chip in a way which avoids damage to any such terminals.

A through aperture 26 in the base surface 14 of the track enables a link connecting the pusher blade 17 and the actuator 18 to move backwards and forwards with the blade 17, so that the actuator 18 may lie beneath the base surface 12.

The magazine 13 is preferably formed from plastics material treated with a conductive agent to minimize electro-static charging, which could otherwise damage the components within the magazine.

Although the proximity sensors used in the illustrated device are infra-red devices, any other suitable sensors could be . used, for example, micro-switches.

Claims

CLAIMS -1. A method of mass production of a product item assembled from components which include a flat pack integrated circuit chip, which method is characterized by the steps of: 1. providing a magazine which contains a stack of the flat pack chips arranged face to face; 2. locating an open end of the magazine at a dispensing station with the magazine arranged transverse to a delivery track which connects the dispensing station to a presenting station; and causing a pusher blade to reciprocate lengthwise within the delivery track, across the end of the magazine, to drive the chips, at a rate of one per reciprocation, from the dispensing station to the presenting station. 2. A method of mass production of a product item, substantially as hereinbefore described with reference to the accompanying drawings. 3. Apparatus for the mass production of a product item assembled from components which include a flat pack integrated circuit chip, which apparatus is characterized by; 1. a feed channel which extends from a dispensing station to a presenting station and which includes a flat support surface; 2. a pusher blade in the channel above thesupport surface and driven to reciprocate through the dispensing station lengthwise along the channel by an actuator; 3. the pusher blade having a leading edge which moves during said reciprocation between a retracted position in the channel adjacent the dispensing station and an extended position adjacent the presenting station;; 4. a magazine which co-operates at one open end thereof with the channel at the dispensing station, for containing a stack of said circuit chips backed up from the open end transversely away from the channel and urged towards the channel, whereby movement of the blade from its retracted to its extended disposition drives from the stack the circuit chip in the channel and on the end of the stack, and conveys said chip from the dispensing station to the presenting station; and 5. electronic logic circuitry to control the operation of the actuator. 4. Apparatus for the mass production of a product item, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings. Amendments to the claims have been filed as follows 1. A method of mass production of a product item assembled from components which include a flat pack integrated circuit chip, which method is characterized by the steps of:

1. providing a magazine which contains a stack of the flat pack chips arranged face to face;

2. locating an open end of the magazine at a dispensing station with the magazine arranged transverse to a delivery track which connects the dispensing station to a presenting station and with the chip on the end of the stack adjacent the track supported on its exposed face by the track; and

3. causing a pusher blade to reciprocate lengthwise within the delivery track, across the end of the magazine, to drive the chips by pressure of the leading edge of the blade against an edge of the chip on the end of the stack, at a rate of one chip per reciprocation, from the dispensing station to the presenting station along the track, and automatically leave them at the presenting station when the direction of movement of the pusher blade reverses during each reciprocatory cycle.

2. A method of mass production of a product item, substantially as hereinbefore described with reference to the accompanying drawings.

3. Apparatus for the mass production of a product item assembled from components which include a flat pack integrated circuit chip, which apparatus is characterized by; I. a feed channel which extends from a dispensing station to a presenting station and which includes a flat support surface;

2. a pusher blade in the channel above the support surface and driven to reciprocate through the dispensing station lengthwise along the channel by an actuator;

3. the pusher blade having a leading edge which moves during said reciprocation between a retracted position in the channel adjacent the dispensing station and an extended position adjacent the presenting station;;

4. Apparatus for the mass production of a product item, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

4. a magazine which co-operates at one open end thereof with the channel at the dispensing station, for containing a stack of said circuit chips backed up from the open end transversely away from the channel and urged towards the channel, whereby movement of the blade from its retracted to its extended disposition drives from the stack the circuit chip in the channel and on the end of the stack, by pressure of the leading edge of the blade against an edge of the chip on the end of the stack, and conveys said chip from the dispensing station to the presenting station to leave the chip automatically at the presenting station on reversal of the direction of movement of the pusher blade during its reciprocatory cycle; and

5. electronic logic circuitry to control the operation of the actuator.