GB1564830A - Feeding device - Google Patents

Description

(54) FEEDING DEVICE (71) We, EBOSA S.A., of Kapellstrasse 26,2540, Grenchen, Canton of Soleure, Switzerland, a Swiss Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a device for feeding parts to be processed or assembled on a transfer machine.

Such devices are preferably used in the automatic production of elements or of sub-assemblies. They serve to place unfinished parts or components in position on workpiece carriers distributed along the periphery of a rotary table in such a way that they subsequently pass through various stations where processing or assembly operations are carried out. To cite just one example, certain types of barrel-covers for watches are assembled by coaxially superimposing a flat disc having a central hub, a toothed wheel serving as a ratchet, and a spring plate, then riveting these parts to gether. By means of three feeding devices, these individual components of each barrelcover are placed in precisely predetermined positions on the same workpiece carrier at three successive stations, after which the riveting operation is generally carried out at a fourth station.

In certain cases, it is necessary not only to centre the individual parts precisely on the workpiece carriers, but also to align them at a specific angle thereto.

Prior art devices for feeding such parts generally comprise a rotating arm which is pivoted at one end and is adjustable in the direction of its axis of rotation. In order to make such a device rigid enough so that the movements of the rotating arm can be carried out with the desired precision, such prior art devices must be provided with heavy, bulky frames, which sometimes makes it decidedly difficult to set up the device at the edge of the rotary table.

Hence there exists a need for a feeding device of simpler and more compact construction which is capable of eliminating the aforementioned difficulties while ensuring the desired accuracy.

According to the present invention, there is provided a device for feeding parts to be processed or assembled on a transfer machine, wherein a transfer control device and a lowering means are provided at the end of a horizontal feeding channel, the transfer control device being provided with a horizontal slide movable at right angles to the feeding channel, onto which slide the parts are successively transferred from the channel, and the lowering means being provided with a vertical plunger which is movable through the transfer control device after displacement of the slide and which is provided with suction means for capturing the parts after arrival thereof on the slide.

A preferred embodiment of the invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 is an overall elevation, partially in section, of the loading device, Figure 2 is a top plan view thereof, Figure 3 is a section taken on the line III-III of Figure 1, on a larger scale, Figure 4 is a section through a vertical plane taken on the line IV-IV of Figure 3, Figure 5 is a section taken on the line V-V of Figure 1, on a larger scale, and Figures 6, 7, and 8 are detail views, partially in section, illustrating the transport operation.

A rotary table 1 shown in Figures 1 and 2 is provided with workpiece carriers 2 which are regularly distributed along the periphery of the table 1 and which are succesively brought into the area of various tools (not shown) in the course of rotation of the table 1. Each workpiece carrier 2 passes through a loading station at which a part 3 is placed upon it; this operation is carried out by a loading device 4 which is set up at the edge of the rotary table 1 and which comprises a supply bin containing parts 3 in bulk and equipped with a vibrator, a feeding channel 7, a transfer control device 8 provided with a slide 14, and a lowering device 9 provided with a plunger 26. These facilities are mounted on a base plate 5. The transfer control device 8 and the lowering device 9 are borne by a C-shaped support 10 mounted on the base plate 5 beside the vibrating bin 6.

The profile of the feeding channel 7 (Figure 2), which extends from the bin 6 to the transfer control device 8, is adapted to the parts 3. The channel 7 is also equipped with a vibration generator so that the parts 3 move gradually along the channel 7 towards the transfer control device 8.

The transfer control device 8 (Figures 3 and 4) consists chiefly of a rectangular frame 11, secured to a shoulder of the support 10, and of the slide 14 which is movable within the frame 11. In the horizontal upper boundary surface of the frame 11 is a rectangularly-shaped groove 13 extending transversely across the frame 11 and having a round aperture 23 at the bottom. A plate 24 secured to the frame 11 closes off the groove 13 at the top, thus defining a passage of rectangular profile for guiding the slide 14. The plate 24 further includes an elongated slot 12 of the same width as the channel 7 and extending from the right-hand end of the frame 11 (as viewed in Figure 3) to a location over the groove 13. Thus the left-hand end of the slot 12 is situated above the aperture 23. Secured to the slide 14 is a piston rod 15 connected to a piston 16 displaceable within a cylinder 17 secured to the support 10 by means of an attachment plate 18.

It will be seen from the Figures that the slide 14 comprises a recess 19 opening out into the upper boundary surface of the slide 14 near the free end thereof. A cylindrical block 20 is secured in the recess 19 in such a way that a narrow annular slit surrounds the block 20. This slit communicates via an elongated hole 21 in the slide 14 with a connection fitting 22 to which a suction pipe is connected. The slide 14 moves in the grooves 13 and can be pushed back by means of the cylinderpiston unit 16-17 from a forward position, as shown in Figure 4, to a rearward position in which its right-hand end is moved so far to the left that both the aperture 23 and the left-hand end of the slot 12 are free. The control means (not shown) for the unit 16-17 will preferably be of an electronic kind and will be connected to the control means for the other facilities, to be described below, in such a way that all operations of the loading device are carried out automatically in accordance with a predetermined programme. The two end positions of the slide 14 are illustrated in Figures 7 and 8, respectively.

The slot 12 in the plate 24 is on a level with the channel 7. Over part of its length, it is covered by a cover 25, whereas the left-hand end of the slot 12 remains free to permit the movements of the lowering device 9, as will be explained below.

The transfer control device 8 is further equipped with means for controlling the flow of parts 3 to the slide 14. A rectangular lever plate 27 provided with two pins 29 is pivotingly mounted on the frame 11 and controlled by two small, parallel cylinder-piston units 30 held in bores in the support 10. The pins 29 enter a broadened portion of the slot 12 and move from the position shown in Figure 3 into the symmetrical position when the units 30 are driven. By means of the pivoting movement of the plate 27, the furthest advanced of the parts 3 in the slot 12 is released, so that this part 3 can move up to the end of the slot 12, where it then rests upon the upper boundary surface of the slide 14.

The return movement of the lever plate 27 releases the entire row of the parts 3 contained in the channel 7 and in the slot 12, so that these parts 3 move towards the left until the first of them arrives at the pin 29 barring the way. Thus each back-andforth movement of the plate 27 causes a part 3 to be transported from the channel 7 onto the slide 14. The suction effect produced through the hole 21, the fitting 22, and the suction pipe attached to the latter is intended to centre the part 3 precisely over the block 20. At the same time, this suction means permits a check on the transport operation, for whenever a part 3 closes off the annular suction slit in the slide 14, an underpressure is produced in the suction line, which underpressure can be utilized for initiating the next operation.

Suction is interrupted in the suction pipe, and the lowering device 9 is set in motion.

The movable portion of the lowering device 9 consists of the longitudinally displaceable plunger 26 which is borne and guided by the upper end portion of the support 10 and which is driven by a cylinder-piston unit disposed in the support 10 itself. A piston 31 of this unit is secured to the plunger 26 and slides in a bore 32 in the support 10; the bore 32 forms the actual cylinder and is bounded by bearings 32a and 32b. The plunger 26 is movable between an upper position (Figure 6) and a lower position (Figure 8). In the embodiment illustrated, the plunger 26 can furthermore be stopped in an intermediate position (Figure 7). Whereas the upper position is determined by a stop ring 100, the intermediate and lower positions are determined by a stop ring 33 adjustably attached to the plunger 26. In the intermediate position, the stop ring 33 rests upon a laterally displaceable bracket 34, the arms of which extend on each side of the plunger 26, and which slides in a track 35 provided in the support 10. The bracket 34 is driven by a cylinder-piston unit 36 affixed to the support 10. When the bracket 34 has been laterally displaced towards the left, the plunger 26 can drop from the intermediate position into the lower position, the latter being determined by the stop ring 33 coming to rest on the bottom of the track 35.

In the embodiment illustrated, the plunger 26 consists of various parts. The ring 33 is secured to a plunger body 37 which is guided by the aforementioned guide members 32a and 32b disposed at the ends of the bore 31 and which bears at its upper end a motor frame 38 to which the stator of an electric motor 39, disposed coaxially with the plunger 26, is attached.

The rotor of the motor 39 is connected by a friction coupling 40 to a rotary shaft 41 whiich is housed within the body 37 and bears at its lower end a plunger head 42. The head 42 is set in rotation by the motor 39; this rotation can, however, be blocked by controllable stop means when the head 42 is in a predetermined angular position. As may be seen in Figure 5, these stop means consist of a powl 43 which is pivotingly mounted on the motor frame 38 and biased by a tension spring 44. The pawl 43 is further controlled by a cylinderpiston unit 45 and cooperates with a spiral cam 46 secured to the shaft 41. As long as the pawl 43 is kept disengaged from the cam 46 by the unit 45, the motor 39 can drive the shaft 41 in the direction of the arrow 47 via the friction coupling 40.

However, when the cylinder-piston unit 45 is shut off, the spring 44 causes the pawl 43 to obstruct the shoulder of the cam 46 and tQ block the shaft 41 in the direction predetermined by adjustment of the cam 46. Passing through the shaft 41 there is also a suction channel 48 which communicates via a duct 49 with a suction or blowing pipe (not shown). The channel 48 passes through the head 42 and opens out into the end face of the plunger 25. Projecting from this end face are a centering bolt 50 secured to the plunger head 42 and an eccentrically disposed entrainer pin 51 secured to a movable stop bolt 52. The function of the entrainer pin 51 will be explained below. The stop bolt 52 is slidingly disposed in the head 42 and is biased by a spring 53.

The mode of operation of the preferred embodiment of the invention as shown in the drawings will now be explained with particular reference to Figures 6, 7, and 8. In this embodiment, the lowering device 9 enables the loading of the workpiece carriers 2 with parts 3 in the form of flat discs having a central hole 55 and an eccentrically bored alignment hole 54, the workpiece carriers 2 possibly having already been loaded with another part at a previous station. The parts 3 are placed on the workpiece carriers 2 not only coaxially with the latter but also at a predetermined angle. In Figure 6, the slide 14 is initially in its forward position. A part 3 which has been released by the flow controlling means 27-30 has arrived on the upper boundary surface of the slide 14.

The plunger 26 is in its upper position, with the pin 51 and the bolt 50 projecting from its end face.

As soon as the check on the presence of the part 3 at its proper location on the slide 14 has taken place, the plunger 26 is lowered into its intermediate position (Figure 7). The centring bolt 50 enters the central hole 55 of the part 3, whilst the pin 51 rests on the part 3 itself and pushes the stop bolt 52 back counter to the bias of the spring 53 in the head 42. The motor 39 is then switched on, the pawl 43 being kept disengaged. The pin 51 enters the alignment hole 54 as soon as it is in angular agreement therewith and thus entrains the part 3. After one revolution, the pawl 43 is actuated and blocks the shaft 41. Air is exhausted through the channel 48 and the duct 49, so that the part 3 is caused to lie against and adhere to the face of the plunger 26, which end face has been about .05 mm. from the surface of the part 3 in the intermediate position. The underpressure occurring in channel 48 and duct 49 is evaluated as a signal for the control of the next operation. Thus this underpressure controls the shifting of the slide 14 as well as the lowering of the plunger 26 into the lower position. In order to bring about this last operation, the cylinder-piston unit 36 is driven in such a way that the bracket 34 is retracted from the position shown in dot-dash lines in Figures 4 into the position shown in solid lines. The plunger 26 then drops through the slot 12 and the aperture 23 into the position shown in Figure 8, so that the part 3 is now placed on the workpiece carrier 2 in the desired direction. The suction through the channel 48 and the duct 49 is then stopped and replaced by a blowing action, which separates the part 3 from the plunger 26 and sets the former on the workpiece carrier 2. The plunger 26 and the slide 14 are then returned to the upper and the right-hand position, respectively.

If it is not necessary to align the part 3 in a predetermined direction about its axis, a lowering device of simpler construction than the device 9 described above may be used, for in such a case the plunger may be made in one piece. Nor need it be equipped with a motor. It will merely move up and down. However, there may be cases in which an intermediate position is nevertheless desired. If, for example, the part 3 is a gearwheel having an upwardly projecting hub, the upper position of the plunger must be such that the part 3 can move freely from the feeding channel onto the slide. In this mutual position of the plunger and the part, however, the plunger cannot suck the part up. Hence the plunger must drop from the upper position into an intermediate position in which a recess provided in its end face surrounds the hub of the part 3, and the end face ofthe plunger is about .05 mm. away from the web of the gearwheel. In such an embodiment, the support 10 will be provided with the described unit 36 and the bracket 34.

In a further embodiment, the lowering device might be designed as a tool capable of carrying out certain operations, such as a riveting or a stamping operation, for example. In that event, the cylinder 32 would be adapted to act upon the plunger 26 with sufficient force. Furthermore, the plunger end face would be adapted for the operation to be performed.

In another variation, the flow controlling means (27-30) might be so disposed that the pins 29 cooperate with the side surfaces of the hubs of the parts 3 rather than with the edges of the discs as described above.

As already mentioned, the functions of the loading device may be programmed by means of an electronic control. The normal order of operation is as follows: (1) release of a part by the flow control ling means 28-30 (2) checking the sliding of the parts on the slide 14 by means of under pressure in the suction pipe con nected to the fitting 22 (3) turning off the suction in the slide 14 and turning on the suction in the plunger 26 (4) checking the adhesion of the parts to the plunger 26 (5) displacement of the slide 14 towards the left (6) lowering of the plunger 26 (7) blowing the part onto the workpiece carrier 2 (8) lifting the plunger 26 (9) displacement of the slide 14 towards the right (10)-(1) release of a part by the flow controlling means.

For parts having a particular design and requiring additional intermediate operations, these additional operations are intercalated in the order listed above.

WHAT WE CLAIM IS: - 1. A device for feeding parts to be processed or assembled on a transfer machine, wherein a transfer control device and a lowering means are provided at the end of a horizontal feeding channel, the transfer control device being provided with a horizontal slide movable at right angles to the feeding channel, onto which slide the parts are successively transferred from the channel and the lowering means being provided with a vertical plunger which is movable through the transfer control device after displacement of the slide and which is provided with suction means for capturing the parts after the arrival thereof on the slide.

2. A device as claimed in claim 1, wherein the lowering means comprises a vertically guided plunger, the lower end face of which is designed as a capturing surface for the parts and provided with the said suction means.

3. A device as claimed in claim 2, wherein the plunger is movable between an upper and a lower position, the said capturing surface lying in the upper position at a distance from the slide such that a part can be conveyed between the capturing surface and the slide.

4. A device as claimed in claim 3, wherein the plunger is movable from the upper position into an intermediate position in which the said suction means are situated directly above a horizontal surface of the part.

5. A device as claimed in Claim 1, wherein the slide is provided with suction means.

6. A device as claimed in Claim 2, wherein the plunger is rotatingly disposed and is provided with a spring-biased entrainer projecting from the said capturing surface.

7. A device for feeding parts to be processed or assembled on a transfer machine, substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. a blowing action, which separates the part 3 from the plunger 26 and sets the former on the workpiece carrier 2. The plunger 26 and the slide 14 are then returned to the upper and the right-hand position, respectively. If it is not necessary to align the part 3 in a predetermined direction about its axis, a lowering device of simpler construction than the device 9 described above may be used, for in such a case the plunger may be made in one piece. Nor need it be equipped with a motor. It will merely move up and down. However, there may be cases in which an intermediate position is nevertheless desired. If, for example, the part 3 is a gearwheel having an upwardly projecting hub, the upper position of the plunger must be such that the part 3 can move freely from the feeding channel onto the slide. In this mutual position of the plunger and the part, however, the plunger cannot suck the part up. Hence the plunger must drop from the upper position into an intermediate position in which a recess provided in its end face surrounds the hub of the part 3, and the end face ofthe plunger is about .05 mm. away from the web of the gearwheel. In such an embodiment, the support 10 will be provided with the described unit 36 and the bracket 34. In a further embodiment, the lowering device might be designed as a tool capable of carrying out certain operations, such as a riveting or a stamping operation, for example. In that event, the cylinder 32 would be adapted to act upon the plunger 26 with sufficient force. Furthermore, the plunger end face would be adapted for the operation to be performed. In another variation, the flow controlling means (27-30) might be so disposed that the pins 29 cooperate with the side surfaces of the hubs of the parts 3 rather than with the edges of the discs as described above. As already mentioned, the functions of the loading device may be programmed by means of an electronic control. The normal order of operation is as follows: (1) release of a part by the flow control ling means 28-30 (2) checking the sliding of the parts on the slide 14 by means of under pressure in the suction pipe con nected to the fitting 22 (3) turning off the suction in the slide 14 and turning on the suction in the plunger 26 (4) checking the adhesion of the parts to the plunger 26 (5) displacement of the slide 14 towards the left (6) lowering of the plunger 26 (7) blowing the part onto the workpiece carrier 2 (8) lifting the plunger 26 (9) displacement of the slide 14 towards the right (10)-(1) release of a part by the flow controlling means. For parts having a particular design and requiring additional intermediate operations, these additional operations are intercalated in the order listed above. WHAT WE CLAIM IS: -

1. A device for feeding parts to be processed or assembled on a transfer machine, wherein a transfer control device and a lowering means are provided at the end of a horizontal feeding channel, the transfer control device being provided with a horizontal slide movable at right angles to the feeding channel, onto which slide the parts are successively transferred from the channel and the lowering means being provided with a vertical plunger which is movable through the transfer control device after displacement of the slide and which is provided with suction means for capturing the parts after the arrival thereof on the slide.

2. A device as claimed in claim 1, wherein the lowering means comprises a vertically guided plunger, the lower end face of which is designed as a capturing surface for the parts and provided with the said suction means.

3. A device as claimed in claim 2, wherein the plunger is movable between an upper and a lower position, the said capturing surface lying in the upper position at a distance from the slide such that a part can be conveyed between the capturing surface and the slide.

4. A device as claimed in claim 3, wherein the plunger is movable from the upper position into an intermediate position in which the said suction means are situated directly above a horizontal surface of the part.

5. A device as claimed in Claim 1, wherein the slide is provided with suction means.

6. A device as claimed in Claim 2, wherein the plunger is rotatingly disposed and is provided with a spring-biased entrainer projecting from the said capturing surface.

7. A device for feeding parts to be processed or assembled on a transfer machine, substantially as hereinbefore described with reference to the accompanying drawings.