EP0407656A1 - Transfer device for transferring elongated workpieces such as pieces of wire and the application of such a device in a wire-working machine for manufacturing pins - Google Patents

Abstract

The invention relates to a transfer device for transferring elongated workpieces. The prior art comprises devices for transferring a plurality of workpieces transversely to their longitudinal axis successively from one processing station into at least one other processing station by means of an articulated conveyor belt, on which the workpieces can be clamped via their circumferential surfaces. The disadvantage of this transfer device is its inaccuracy in transferring and positioning the workpieces. The object of the invention is to transfer workpieces of various cross-sectional shapes accurately, even at high speed, into a particular position in a processing station. This object is achieved by two concurrently and adjacently running strands of two conveyor belts (12 and 28; 192) which are guided between the stations to ensure that the strands rest firmly on both sides of the transferred workpieces (52; 186), and by at least one toothed belt (12 or 28; 192) as conveyor belt, the tooth gaps (76 and 78 respectively) of which take up the workpieces (52; 186) individually. The advantage of this solution to the object is the accurate transfer of the workpieces and positioning of the latter without regard to workpiece peculiarities and the rhythm and speed of transfer of workpieces following closely upon one another. <IMAGE>

Description

The invention relates to a device according to the preamble of claim 1.

DD-PS 41 141 discloses such a device for guiding needles, wire shafts and the like to machining tools, in particular grinding and polishing tools for removing the embossing burr which is formed during the embossing and punching of the ear area. For this purpose, the workpieces are moved transversely to their longitudinal axis by means of an elastic circumferential conveyor belt on which elastic clamping devices having two or more jaws are riveted at intervals, which automatically open and close when the conveyor belt is deflected for receiving and dispensing the workpieces and then the workpieces lead tightly past the tools. The clamping devices are loaded and emptied by means of a feed or ejection device. Spring elements are also provided so that the workpieces maintain the correct working position during feeding into the clamping devices.

With this known device, the workpieces to be machined can only be continuously moved past the machining tools for the grinding or polishing process, the elastic conveyor belt giving way to the workpieces due to the machining pressure of the tools. A precise and step-by-step approach of the parts is therefore not possible. Furthermore, the jaws of the clamping device must be adapted in shape and size to the respective workpiece diameter.

The invention is based on the object of creating a transport device that can be used as universally as possible, with which pieces of wire that lie within a specific, as large as possible diameter and length range, with one and the same transport means, were intermittently and quickly located on one or more processing stations arranged next to one another - and can be fed precisely.

Starting from a device of the type mentioned at the outset, this object is achieved according to the invention by the characterizing features of claim 1.

The parallel runs of two toothed belts can be arranged so that their teeth are directed towards each other, i.e. Tooth on tooth shows, that is, the straps rotate in mirror image to each other, or the teeth of one or the other strand can run somewhat offset, possibly to the extent that the teeth of one strand lie over the tooth gaps of the other strand. A variant is that both dreams run in the same position, i.e. the interlocking of both dreams e.g. points upwards. The belt spacing is adjustable in all four cases. The toothed belts are placed against each other in such a way that the pieces of wire are firmly clamped by the tooth flanks of at least one toothed belt during transport. Due to the aforementioned installation variants of the toothed belts, all wire piece diameters that are within the working area of a machining or processing machine can be quickly and precisely transported with one belt dimension.

These advantages make it possible for the transport device according to the invention to be used, for example, in a device for producing precision wire pencils with precisely accurate wire pin head shape and size, as are required for further use in automatically operating nailing devices for trouble-free functioning of these devices . Furthermore, it could also be part of a device for producing workpieces that require upsetting processes in several steps, for example in multi-stage presses. In this case, too, the transport device works so precisely that the raw material to be processed parts safely and immovably maintain the working position through all the deformation stations arranged next to each other (each with clamping device). The device can therefore be used wherever a precise step-by-step transport process is important.

The invention therefore also relates to the use of a transport device according to the invention in a wire processing machine, in particular a pin press, as a device for producing wire pins, in particular head nails.

• Fig. 1 die erste Ausführungsform in Vorderansicht in teilweise abgebrochener Darstellung
• Fig. 2 eine Seitenansicht, teilweise geschnitten dargestellt, der ersten Ausführungsform
• Fig. 3 das Transportriemenpaar von Fig. 1, vergrößert, wobei die Teilfigur a dieses für einen kleineren Verkstückdurchmesser und Teilfigur b für einen größeren Werkstückdurchmesser zeigt
• Fig. 4 das Transportriemenpaar von Fig. 3, jedoch anders arbeitend, eben­falls für einen kleineren und größeren Werkstückdurchmesser gezeigt
• Fig. 5 das Transportriemenpaar von Fig. 3, in einer dritten Weise arbeitend, ebenfalls für einen kleineren und größeren Werkstückdurchmesser ge­zeigt
• Fig. 6 das Transportriemenpaar der Variante der ersten Ausführungsform, ebenfalls für einen kleineren und größeren Werkstückdurchmesser ge­zeigt
• Fig. 7 die zweite Ausführungsform in Draufsicht, in abgebrochener Darstel­lung

In the following, the invention is explained in detail with reference to two preferred embodiments of the device according to the invention and a variant shown by way of example in the drawing. Show it:

• Fig. 1 shows the first embodiment in front view in a partially broken view
• Fig. 2 is a side view, shown partially in section, of the first embodiment
• Fig. 3, the pair of conveyor belts of Fig. 1, enlarged, the partial figure a shows this for a smaller cross-section diameter and part figure b for a larger workpiece diameter
• Fig. 4 shows the pair of conveyor belts of Fig. 3, but working differently, also for a smaller and larger workpiece diameter
• Fig. 5, the pair of conveyor belts of Fig. 3, working in a third way, also shown for a smaller and larger workpiece diameter
• Fig. 6 shows the pair of conveyor belts of the variant of the first embodiment, also shown for a smaller and larger workpiece diameter
• Fig. 7 shows the second embodiment in plan view, in a broken away view

First embodiment and its variant

1 and 2, the lower horizontal run of an endless, upper toothed belt (12) in an upper horizontal guide (14) with lateral vertical guide surfaces (16), which are somewhat lower than the dimension from the tooth base to the back of the belt, is used as the transport belt, and guided on an upper guide surface (18) corresponding to the belt width. The toothed side of the upper toothed belt (12) points downwards.
The upper guide (14) is firmly screwed into two identically designed holders (20) which are height-adjustable in slots. The holders (20) are attached to the machine body (24). The strand of the toothed belt (12) shown is deflected upwards by means of a plurality of toothed and / or smooth disks, not shown, which are arranged at one end of the guide (14) and in the vicinity thereof. Furthermore, as an additional transport belt, the upper horizontal run of a second endless, lower toothed belt (28) is guided with the toothed side pointing upwards in a guide (30) of the same design corresponding to the guide (14). This strand is diverted downwards. The guide (30) is fastened in holders (32), which are also adjustable in height.

The endless toothed belts (12 and 28) can either via a gear transmission and the toothed or deflection pulleys jointly by a motor-driven stepper transmission, or, depending on the desired transport speed, jointly by a controllable servo motor, or separately, each by a controllable servo motor same direction, which corresponds to the desired transport direction, are driven intermittently.

In the middle between the holders (20 and 32) (Fig. 1) are the front parts (40 and 42) of an upper or lower lever or slide a clamping device (44), e.g. B. a device for the production of wire pins arranged. In a tool holder (46) of the front part (40 or 42) of each lever or slide, a cheek-like clamping tool (48) of the same design is fixed in an adjustable manner for clamping a wire pin blank (52).

2 also shows an upsetting tool (60) of an upsetting device of the aforementioned device for molding a head (54) onto the wire pin blank (52). The upsetting tool (60) is arranged in the center of the toothed belt pair (12, 28) in front of the clamping tools (48). The machine body (24) is provided with a trapezoidal groove (26) over the entire length of the transport path so that the pin blanks (52) and the finished wire pins (58) can be transported through.

On the left in FIG. 1, two levers (66 and 68) of a wire cutting device (70) of the device for producing wire pins are pivotably mounted in a common bearing (64). A cutting tool (72) of the same design is provided in a tool holder of each lever (66 or 68) for cutting the wire to length and for pyramid-shaped sharpening of the wire pin blanks (52).

The two guides (14 and 30) end a short distance to the right in front of the cutting tools (72), while the lower and upper runs of the toothed belts (12 and 28) extend slightly beyond the cutting tools (72) before both runs go up or redirected downwards. The length of the guides (14 and 30) on the right side of the device in Fig. 1 depends on the number of work stations arranged side by side for the clamping and upsetting operations and on the way in which the pins produced are removed.

Is the transport device part of the device for the production of Wire pins, which show the figures 1 to 6 of the drawing, the workflow is as follows:

A feed, not shown, but known, pulls the wire from the coil of wire through a straightening apparatus and pushes as much wire (out of the drawing plane in FIG. 1) through the opened cutting tools (72) and the lower or upper run of the toothed belt (12 and 28) through, as is required for the desired wire pin length and for shaping the wire pin head. Now the cutting tools (72) acting against each other cut off the wire by pivoting the cutting lever (66 and 68), a pyramid-shaped wire pin tip (56) being produced. The intermittent drive of the pair of toothed belts (12, 28) stops during the insertion into the two belt spaces and the cutting of the wire. The intermittent drive is then briefly switched on again and the pair of toothed belts (12, 28) is moved further, for example by four teeth in the exemplary embodiment, and stopped again for a new wire feed. This happens repeatedly until a cut-to-length pin blank (52) comes to rest between the clamping jaws (48) of the clamping device (44).

The wire to be cut to length can now be inserted according to FIG. 3 or 4 into tooth gaps (76 and 78) of the opposing teeth (80 and 82) of the toothed belt (12 and 28), or according to FIG. 5 into a tooth gap (78) of the upper run of the Toothed belt (28) and on the tooth head (86) of a tooth (80) of the run of the upper toothed belt (12) are inserted, or, depending on the relative longitudinal arrangement of the toothed belt (12 and 28), in a tooth space (78) of the run of the lower toothed belt (28) and against the toothed belt back (84) of the run of the upper toothed belt (12) are inserted (FIG. 6). If pins with a different wire diameter are to be manufactured and transported, all that is required is the distance between the two parallel strands by moving the holders (20 and 32) towards one another or apart. to be changed. The guides (14 and 30) are also moved. See sub-figures a and b of FIGS. 3 to 6. If the change in wire diameter exceeds the range that can be covered with this belt arrangement according to FIG. 3, the toothed side of the upper toothed belt (12) is turned upward, so that the teeth (80 and 82) of the two belts (12 and 28) now point in the same direction, namely upwards (Fig. 6). This allows pins with an even smaller wire diameter to be transported safely. Approximately the same wire diameter as in the arrangement according to FIG. 6 can be used according to the arrangement. Fig. 4 also safely transport that the teeth (80) and tooth gaps (76) of the upper toothed belt (12) to the teeth (82) or tooth gaps (78) of the lower toothed belt (28) constantly by a certain amount in the direction of transport offset, in the present example leading intermittently. Here, the pin blanks (52) are pressed from the left tooth flanks of the teeth (80) of the run of the upper toothed belt (12) against the right tooth flanks of the teeth (82) of the run of the lower toothed belt (28) and thus, securely clamped, transported step by step .

5 and the teeth (80) of the upper toothed belt (12) are so far advanced to the teeth (82) of the lower toothed belt (28) that the Teeth (80) of the upper toothed belt (12) cover the tooth gaps (78) of the lower toothed belt (28). The pin blanks (52) are then pressed by the tooth heads (86) of the teeth (80) of the upper toothed belt (12) against the adjacent tooth flanks of the teeth (82) of the lower toothed belt (28).

When executing acc. Fig. 3, the pin blanks (52) are clamped between two adjacent tooth flanks of the teeth (80 and 82) of the two toothed belts (12 and 28).

When executing acc. Fig. 6 presses the back (84) of the upper toothed belt (12) the pin blank (52) against the adjacent tooth flanks of the teeth (82) of the lower toothed belt (28).

In all four types of transport mentioned, the fixation of the pin blanks (52) during their step-by-step transport is supported by the adjustable contact pressure of the guide rails (14 and 30). Through the lateral guide surfaces (16) of the guides (14 and 30), the toothed belts (12 and 28) are also guided laterally immovably over the transport route.

As already mentioned, the pin blanks (52) are guided and held exactly, transported step by step, between the clamping tools (48) of the clamping device (44), with a short wire end, which is required for forming the wire pin head (54), in FIG. 2 protrudes to the right from the clamping tools (48). Then the clamping tools (48) close and hold the pin blank (52) until the upsetting tool (60) has upset the head (54), the clamping tools serving as an anvil. After the clamping tools (48) have opened again and the upsetting tool (60) has assumed its rear position, the finished pin (58) is moved one step further out of the tool area, while a new pin blank gets between the tools (48, 60) and the process begins again. After a few transport intervals, the finished pins (58) fall out safely via a slide at the end of the straight transport route without an additional ejector, or the orderly arriving finished pins can also be removed and removed individually for magazine or other processing. As mentioned, further clamping and upsetting devices could also be arranged next to one another between the clamping and upsetting device and the point of failure of the finished pin, if the loading or ver work of the wire blanks must be carried out in several upsetting stages.

It should also be mentioned that with the transport device according to the invention in connection with the device for producing wire pins up to 800 pins per minute can be produced, i. h that the transport frequency can be 13 per second.

Second embodiment

In Fig. 7, a carriage (112) of an upsetting device (114), which is part of a device for producing wire pins (182), is connected to a connecting rod via a bolt which is seated in the forked end of the carriage (112), which is not shown is held by means of a connecting rod cover on a short-stroke crank pin of a drive shaft of the device. The carriage (112), shown in its front working position in FIG. 7, has a dovetail guide over its entire length and is slidably mounted between two guide strips (132) on a base plate in the machine frame (136). At its end shown, a threaded flange (140) with an internal thread is fastened to the carriage (112), in which a set screw (142) is screwed, which is countered by means of a ring nut (144).

In the axial extension of the set screw (142), a compression spring-loaded compression tool (154) of the compression device (114) is arranged in a separate guide (148) in the bearing bushes and can be moved longitudinally, with sliding bearings.

The guide (148) with the floating upset tool (154) is attached to the machine frame (136) in an easily removable or replaceable manner by means of two stud bolts (166). Thanks to a return spring, the compression tool (154) is permanently non-positively on the hexagon head of the set screw (142). Also in the extension of the axis of the upsetting tool (154), two clamping tools (176) of a clamping device (178) of the device for producing wire pins (182), which act against one another in a lever or slide, are arranged in the immediate vicinity of this and symmetrically to this axis . In FIG. 7, a wire pin (182) with an upset head (184) is firmly clamped between the clamping tools (176). The shaft of the wire pin (182) protruding from the clamping tools (176) in FIG. 7 lies, firmly clamped, in the tooth gaps of two Toothed belt as a transport belt of a transport device of the device for producing wire pins shown in FIG. 7 above. By means of the two toothed belts, of which only the lower one (192) can be seen, the pin blanks (186), which still have no head (184), are intermittent, in the horizontal and vertical plane, exactly in the middle in front of the upsetting tool (154) of the upsetting device (114) brought up and away from it. The toothed belts (e.g. 192) move gradually across the compression and clamping direction of the compression and clamping device (114,178). By means of a height-adjustable guide rail, of which only the lower one (198) can be seen, the distance of the toothed belts from one another, and thus the tension with which the pin blanks (186) are held in the tooth gaps, can be adjusted. Through the lateral guide surfaces of the guide rails (eg 198), the toothed belts are also moved laterally, immovably, over the transport route.

In Fig. 7, a bearing (202) is attached to the front part of the guide of the carriage (112), in which a rocker arm (206) is mounted on bolts (204). On each arm of this lever (206) a connecting rod (210) engages on a bolt (208), which connects the rocker arm (206) on the one hand to the slide (112) of the upsetting device (114) via a bolt (212) or on the other hand couples a tool holder (214) to a positioning device (216) for the pin blanks (186) via bolts (218). The connecting rods (210) have two joint heads (220, 222) which are connected to one another by a turnbuckle (224).

The tool holder (214) is guided in a longitudinally movable manner in the machine frame (136) by means of two rods (226) lying one below the other. A positioning tool (232) with four working surfaces (234 to 240) for a 4-stage positioning process is arranged on the holder (214), during which the longitudinal position of the pin blanks (186) can be changed.

On the carriage (112), a length is adjustable in a slot additional positioning tool (246) clamped by means of the bolt (212) through which the joint head (222) is fastened. This positioning tool (246) is provided with only two working surfaces (248 and 250) for axially displacing the pin blanks (186) against the direction of displacement of the first positioning tool (232).

On the far left in FIG. 7, the lower of two counteracting cutting tools (252) of a cutting device of the device for producing wire pins for cutting to length from the wire (254) and pyramid-shaped sharpening of the wire pin blanks (186) is indicated.

The mode of operation of the transport device described above is as follows when it is part of a device for producing wire pins, which is partially shown in FIG. 7:
A feed, not shown, but known pulls the wire (254) from the wire supply through a straightening device and pushes as much wire through the opened cutting tools (252) and into the tooth gaps of the two toothed belts (e.g. 192) as for the desired wire pin length and for Forming the wire pin head (184) is required. Now the opposing cutting tools (252), which can each sit in a lever or in a carriage, cut off the wire (254), a pyramid-shaped wire pin tip (188) being created. The intermittent drive of the pair of toothed belts stops for a short time while it is inserted between the two toothed belts and the wire (254) is cut off. The drive is then switched on again for a short time, thereby moving the pair of toothed belts one step further and stopping again before a new wire feed (this could also be done by a stepping gear). This happens until a cut-to-length pin blank (186) comes to rest between the clamping tools (176) of the clamping device (178) and in the middle in front of the upsetting tool (154) of the upsetting device (114).

In order to be able to produce pins in the greatest possible length range with the device without major changeover work, the cutting tools (252) of the cutting device and the clamping and upsetting device (178, 114) of the device for producing wire pins (182) are arranged stationary to compensate for this the different distance from the wire pin tip (188) to the upsetting tool (154) in the manufacture of a different pin length is compensated for by shifting the pin blanks (186) in their longitudinal direction within the transport path between the cutting station and the head upsetting station, as follows:

The pin blanks (186) are positioned by the two positioning tools (232 and 246) of the positioning device (216), the first tool (232) having its four working surfaces (234 to 240) for a gradual feed. The gradual positioning takes place with each advance stroke of the slide (112). When the carriage (112) moves forward, i.e. when each wire pin head (184) is generated, the positioning tool (232) guided in the machine frame (136) is moved to the transport device via the connecting rod (210) and the rocker arm (206) , so that the pin blank (186) located at the time in front of the first working surface (234) of the positioning tool (232) is advanced by a certain amount. As already mentioned, the transport device stands still during this process. While the carriage (112) is running back, the drive is actuated briefly for a transport interval, so that the pin blank (186) previously moved from the working surface (234) of the tool (232) is now in front of the second working surface (236) and at one renewed upsetting is advanced by the same amount. This happens until the pin blank (186) has been moved from the fourth working surface (240) of the positioning tool (232) to its foremost position. In this longitudinal position, the pin blank (186) is gradually transported in the direction of the upsetting station until it comes to rest in front of the working surface (250) of the second positioning tool (246). Also derived from the compression movement of the carriage (112), the pin blank (186) is possibly moved back a short distance from the work surface (250), as a result of which the length tolerances of the pin blanks are compensated so that it has reached its final position, and he In the exemplary embodiment, after two transport intervals, it lies between the clamping tools (176) in such a way that exactly such a large wire end protrudes from the clamping jaws (176) as is required to form the wire pin head (184). In the case of longer pin blanks (186), they are moved back by the second positioning mechanism Stuff (246) in two steps, such that the pin blanks are first moved back from the work surface (248) and then from the work surface (250) to the final position. It is obvious that the positioning device (216) can be dispensed with entirely if only pins of a length order are to be produced, or if no such high pin quality is required. The cutting device is then arranged in such a way that the pin blanks (186) come to rest in the transport device in such a way that such a wire end protrudes from the clamping tools (176) as is required for the head production during the upsetting process.

When the clamping jaws (176) close, they hold the pin blank (186) for the following upsetting process to produce the pin head (184). For this purpose, the drive shaft is set in motion, which gives the carriage (112) a reciprocating movement. This reciprocating movement does this with the compression tool (154), which is not positively connected to the hexagon of the set screw (142) by the return spring, and generates a head (184) on the pin blank (186) with each forward movement, the clamping tools ( 176) serve as an anvil. With each backward movement of the carriage (112), the compression spring relaxes and it pushes the compression tool (154) back, so that it remains in permanent non-positive contact with the adjusting screw (142). The height of the upsetting pressure (and thus also the shape of the wire pin head) can be set by means of the adjusting screw (142) by screwing it more or less far into the threaded flange (140) in the slide (112).

With each transport step, a finished wire pin (182) is moved out of the tool area, while a new pin blank (186) gets between the tools (154 and 176), whereupon the process begins again. After a few transport intervals, the finished pins (182) fall out safely at the end of the transport route without an additional ejector, or they can be ordered incoming finished pens for magazine or other processing can also be automatically removed and removed individually.

Claims (10)

1.) Transport device for transferring elongated workpieces such as wire pieces transversely to their longitudinal axis from one processing station in succession to at least one other processing station; with and with a guided transport belt, to which the workpieces are clamped over its jacket surface, characterized by two adjacent running strands of two conveyor belts (12 and 28; 192) / which between the stations for mutual immovable contact of the strands of the transported workpieces (52 ; 186) are guided; and in that at least one of the two conveyor belts is a toothed belt (12 or 28; 192), the tooth gaps (76 and 78) of which individually accommodate the workpieces (52; 186). 2.) Transport device according to claim 1, characterized in that in the case of two toothed belts (12 and 28) which may have the same profile, their jointly guided strands with teeth of the same direction (80 or 82) or with respect to the transport surface generated by the moving longitudinal axes of the clamped workpieces in mirror image are arranged. 3.) Transport device according to claim 1, characterized in that in the case of two optionally equally profiled toothed belts (12 and 28), their jointly guided strands with opposing teeth (80 or 82) are offset from one another in the transport direction in such a way that the two rows of teeth on the workpieces ( 52; 186) each clamp by means of two tooth flanks facing each other or by means of a tooth gap (78) and a tooth head (86). 4.) Transport device according to one of claims 1 to 3, characterized in that each conveyor belt and each toothed belt (12 or 28; 192) between two adjacent stations in a three-sided guide (14 or 30; 198) of the workpieces (52 ; 186) engages transporting dreams whose teeth (80 or 82) or belt back (84) are exposed. 5.) Transport device according to claim 4, characterized in that the rail-shaped guides (14 and 30) are arranged at least in one of the two transverse directions perpendicular to the transport direction, in any case perpendicular to the longitudinal direction of the workpieces (58). 6.) Transport device according to one of claims 1 to 5, characterized by the addition of a positioning device (216) for arranging the workpieces (186) along their axis, with at least one positioning tool (232 or 246) for displacing at least one workpiece in its longitudinal direction by one predetermined route. 7.) Transport device with positioning device, according to claim 6, characterized in that the positioning tool (232 or 246) has at least one working surface (234 or 236 or 238 or 240 or 248 or 250) movable parallel to the longitudinal direction of the workpieces (186), which acts upon and takes along a workpiece end lying on its route during its working stroke. 8.) Transport device with positioning device according to claim 7, characterized in that the positioning tool (232 or 246) has at least one step, which two adjacent work surfaces (234 and 236, or 236 and 238, or 238 and 240 or 248 and 250) connects with each other. 9.) Transport device with positioning device, according to claim 7 or 8, characterized in that the positioning tool (232 or 246) is a rigid body which can be displaced parallel to the longitudinal direction of the workpieces (186) to be displaced. 10.) Use of the transport device, optionally with a positioning device, according to one of claims 1 to 9 in a wire processing machine, in particular a pin press as a device for producing wire pins, in particular head nails.

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