GB2108453A - Device for feeding blanks to the die of a hot-heading press - Google Patents

Abstract

A blank feeding device comprises a blank feeder bin, a blank loading means, a wheel (3) with pockets (17) to receive blanks (9) when in a heating zone, a means for retaining the blanks (9) in the wheel pockets, a means for removing the blanks (9) from the wheel (3), and a mechanism for advancing the blanks (9) to the die of a press. The blank retaining means is basically a magnetic system which includes permanent magnets (36) having their like poles fixed on the arc-shaped surface of a magnetic plate (37). Connected to the opposite pole of each magnet (36) is a separate plate (38) from a magnetic material. The magnetic system also incorporates magneto- conducting elements (43) and (44) which are respectively fixed on a flat ring (45), in rigid connection with the wheel (3), and on the wheel (3). The plate (37) has its arc-shaped edge presented to the magneto-conducting elements (43) disposed in the heating zone. <IMAGE>

Description

SPECIFICATION Device for feeding blanks to the die of a hot-heading press This invention relates to metal working equipment and more particularly to a device for feeding blanks to the die of a hot-heading press.

The invention is readily applicable to the production of various elements of industrial holders and fasteners, such as wood screws, pins, bolts, studs, dowels and rivets, which are fabricated from a rod while one end of it is heated to a temperature of the order of 1400"C during its delivery to the die of a press.

Blank feeding devices of similar type now in use are disadvantageous in that the blanks are not retained in place when transferred in the heating zone. Known appliances used for holding the blanks in place in the heating zone are rather complicated in construction and unreliable in operation, since the blanks are insecurely fixed in the transport means and therefore drop out of the heating zone. As the dropped-out blanks, heated to elevated temperatures, are unfit for re-use, the percentage of defective products tends to increase.This invention provides a device for feeding blanks to the die of a hot-heading press, which comprises a blank feeder bin, a blank loading means, a wheel geared to a press drive and having pockets arranged over its periphery to receive blanks during their delivery in a heating zone produced by a heater mounted at one end face of the wheel at the upper part thereof, a means for retaining the blanks in the pockets of the wheel in the course of delivery of said blanks in the heating zone, a means for removing the blanks from the wheel, and a mechanism for advancing the blanks to the die press, wherein, according to the invention, the means for retaining the blanks in the wheel nests is a magnetic system including permanent magnets having their analogous poles fixed on the convex surface of an arc-shaped plate from a magnetic material to permit summation of magnetic flux, the opposite pole of each magnet being connected to a separate plate from a magnetic material to permit breaking of magnetic flux, and magneto-conducting elements with a part thereof being secured on a flat ring fixed with the wheel and each being placed opposite the corresponding pocket, the other part of said elements being fixed on the wheel so that each is arranged between the corresponding pocket of the wheel and the axis of rotation of the latter, with the plate for summation of magnetic flux being positioned opposite the heater on the other side of the wheel while the arc-shaped edge of said plate is presented to the magneto-conducting elements of the flat ring which are found in the heating zone and is spaced somewhat apart from these elements so as to form a gap therewith.

The pockets in the wheel of the blank feeding device preferably have the form of slots arranged over the wheel periphery, and the blank loading means is suitably provided with a stop mounted on the body of the feeder bin and having its bearing surface, in a certain position of each slot, in the same plane of contact with the surface of the latter, and a spring-loaded roller for pressing the blank against a respective magneto-conducting element positioned on the flat ring, a double-arm lever with a counterbalance being replaced on one end thereof and the spring-loaded roller on the other The means for removing the blanks from the wheel preferably has a slipway with its upper edge in abutted relationship with the generatrix of the wheel so as to be in intimate contact with the surface of the slot at a time when the blank breaks away from the magneto-conducting elements on its exit from the heating zone.

A magnetic clamp is suitably provided above the slipway of the type having plates from a magnetic material and a permanent magnet placed therebetween, as well as a plate from a non-magnetic material, fixed on the surface of the permanent magnet, facing the slipway and having its edge in parallel relationship with the slipway.

Such construction of the blank feeding device makes it possible, due to the provision of a magnetic system, to ensure reliable delivery of blanks in the heating zone or, in other words, to prevent the blanks from dropping out of the wheel pockets when in the heating zone and thus to reduce the percentage of defective products.

As compared with known devices of similar type, the described device is more simple in construction, prevents dynamic loads from acting on the blanks, and permits a shorter time required for their travel; it also makes it possible to simplify the construction of the means for loading the blanks into, and removing them from, the pockets of the wheel without interrupting its operation.

Such structural arrangement of the above means permits the operating reliability of the equipment to be enhanced by not less than 25 percent along with a higher production efficiency thereof.

Additionally, the overall weight of the blank feeding device according to the invention is substantially reduced.

The invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a schematic general view of a device for feeding blanks to the die of a hot-heading press; Figure2 is an enlarged cross-section on line ll-ll of Figure 1; Figure 3 is an enlarged cross-section on line Ill-Ill of Figure 2; Figure 4 is an enlarged cross-section on line IV-IV of Figure 2; Figure 5 is a plan view on an enlarged scale of a blank loading means; Figure 6 is a plan view taken on an enlarged scale of a means for removing the blanks from the wheel and of a mechanism for advancing the blanks to the die of a press.

Referring now to the above drawings and to Figure 1, in particular, a blank feeding device comprises, sequentially arranged, a blank feeder bin 1,a blank loading appliance 2, a wheel 3 adapted for the delivery of blanks in the heating zone, a means 4 for retaining the blanks in the wheel pockets when in the heating zone, a means 5for removing the blanks from the wheel 3, and a mechanism 6 for advancing the blanks to a die of a press.

A housing 7 of the feeder bin 1, which may be of any conventional type, has an inclined labyrinth 8 through which the blanks are transferred to the wheel 3. Simultaneously, the labyrinth 8 is used to store blanks 9, the maximum and minimum number of which is controlled by delay-action sensors 10, which may be of any conventional design. Mounted on a pivot 11 at the entrance to the labyrinth 8 is a lever 12.

The loading appliance 2 comprises a roller 14 and a double-lever 15 pivoted at 16, which are mounted on the housing 8 of the feeder bin 1.

The wheel 3 for delivering the blanks 9 in the heating zone has pockets 17 adapted to receive the blanks. The pockets 17 are equally spaced over the circumference. The pockets 17 have the form of slots on the periphery of the wheel 3 in parallel relationship with the axis of rotation of the wheel 3. The heating of the blanks 9 in a heating zone "a" (shown by a brace) is performed by means of an induction heater (not shown), which may be of any conventional type. The heater is mounted on the wheel 3 at its upper part to produce the heating zone "a". Fixed in position between the heater and the wheel 3 on its shaft is a disc 18 whose upper part, opposite the nests 17 in the wheel 3, is formed with slots 19 conforming in shape to the pockets 17.The wheel 3 is set in motion by means of a drive including an electric motor 20, which at one side is geared through a shaft 21 and a worm-gear speed reducer 22 to a shaft 23 of the wheel 3. At the other side, the motor 20 is geared through a worm-gear speed reducer 24 to a turn table 25 of the press die. The gearing is shown by arrows.

As the wheel 3 rotates, the stop 13 has its bearing surface 26, in a certain positiqn of each pocket 17, in the same plane of contact with the surface of the corresponding nest 17. In this way the blanks 9 are strictly fixed in position with respect to the corresponding pockets 17 at a time when the blanks 9 are loaded into the pocket 17 of the wheel 3. The bearing surface 26 is preferably made curvilinear in shape with the radius of curvature being equal to the distance between the axis of the wheel 3 and the pocket 17.

The means 5 for removing the blanks 9 from the wheel 3 has a slipway 27 the upper edge of which is contiguous to the generatrix of the wheel 3 and in contact with the surface of each pocket 17 found on the level of the slipway 27 in one of the positions of the pocket 17 at the moment of exit from the heating zone "a". Fixedly mounted above the slipway 27 is a magnetic clamp incorporated in the blank removing means 5. The magnetic clamp comprises two plates 28 from a magnetic material, for instance, magnetic electrical steel, which are located underneath the slipway 27. Fixed in the interspace between the plates 28 is a permanent magnet 29 whose surface, presented to the slipway 27, carries a plate made of non-magnetic material, for instance, any constructional non-magnetic steel.The plate 30 is rigidly fixed on the surface of the permanent magnet 29 in parallel relationship with the plates 28, and has chamfered edge in parallel relationship with the slipway 27.

The mechanism 6 for advancing the blanks 9 to the die of the press may be of any conventional type. In the preferred embodiment it comprises a roller conveyor 31, guides 32 with a collecting launder 33 which holds the blank 9 in place with respect to the turn table 25 of a die. Mounted in front of the collecting launder 33 on a shaft 34 is a shut-off member 35 provided for intermittent feeding of the blanks to the press die. Shown in Figure 1 by arrows is the direction of travel of the blanks 9 in the form of round rods.

The means 4 for retaining the blanks 9 in the nests of the wheel 3 when in the heating zone "a" is basically a magnetic system consisting of permanent magnets 36 (Figure 2,3) whose like poles are fixed on the convex surface of an arc-shaped plate 37 made of a magnetic material, for example, magnetic electrical steel, provided for summation of magnetic flux. The opposite pole of each permanent magnet 36 is connected to a separate plate 38 from a magnetic material for breaking magnetic flux. The plate 38 may be manufactured from the same material, i.e. from magnetic electrical steel, as the plate 37.

The part of the magnetic system including the plate 37, permanent magnets 36 and plates 38, held in place by means of bolts 39 (Figure 2), 40 and 41 on a face-place 42, is stationary mounted at the upper part of the wheel 3 in opposite space relationship with the heater.

The other part of the magnetic system of the means 4 comprises magneto-conducting elements 43,44 (Figure 2,4) of which the elements 43 are fixed on a flat ring 45 in rigid connection with the wheel 3.

The elements 44 are fixed immediately on the wheel 3, each between the corresponding pocket 17 of the wheel 3 and the axis of rotation of the wheel 3. The magneto-conducting elements 43, corresponding in number to the number of pockets 17 in the wheel 3, are made in the form of cylinders from magnetic electrical steel, approaching in diameter the blanks 9, which are pressed into holes formed in a flat ring 45 overthe periphery. The ring 45 is rigidly fixed, for example, by means of welding, on the wheel 3 so as to permit each of the magneto-conducting elements 43 to be in opposite spaced relationship with the corresponding pocket 17.

The magneto-conducting elements 44 are made in the form of flat rectangular plates from magnetic electrical steel. A number of magneto-conducting elements 44 also corresponds to that of the pockets 17 in the wheel 3, with each element being positioned radially on the wheel 3 and fixed in position thereon so that one of its edges is level with the pocket 17.

The plate 37, provided for summation of magnetic flux, is positioned so that its arc-shaped edge faces the magneto-conducting elements 43 of the flat ring 45 present in the heating zone, and is spaced somewhat apart from the elements 43 so as to form a gap "b" therewith. The plates 38 are spaced with a gap "c" relative to the magneto-conducting ele ments 44. The size of these gaps "b" and "c" (Figure 2), as well as the length of arc of the plate 37 and the number of permanent magnets, are selected with a view to permitting the blank 9 to be reliably retained in the heating zone "a" (Figure 1).Additionally, it is necessary that at the exit from the heating zone "a" (Figure 1) the action of the magnetic system should be diminished to such an extent as to permit the blank 9 to be freely separated from the elements 43 (Figure 2) and 44 under its own weight so as to drop out of the nest 17.

Shown in Figure 5 is the manner in which the blank 9 is conveyed by means of a feed conveyor 46 and the lever 12, spring-loaded at 46, through the feeder bin 1 into the pocket 17 of the wheel 3. The roller 14, incorporated in the blank loading means 2, is spaced somewhat apart from the magnetoconducting elements 43 by a distance not less than the length of the blank 9. As mentioned above, the roller 14 is used to press the blank 9 against the magneto-conducting element 43. To this end, the roller 14 is secured to a bracket 48 through the agency of a spring 49 by means of which the roller 14 is moved along the axis of the nest 17.

The double-arm lever 15, incorporated in the blank loading appliance 2, is intended to press the blank 9 against the magneto-conducting elements 44.

Placed on one end of the double-arm lever 15 is a counterbalance 50 and on the other end a roller 51.

Shown in Figure 6 is the process of delivery of the blank 9 from the wheel 3 to the turn table 25 of the press die. To position the blanks 9 in the press die, the mechanism 7 also includes a pusher 53 fixed on a slide 54 of the press coaxiallywith an opening 55 in the press die. To permit intermittent feeding of the blanks 9 to the collecting launder 33, a faceplate 56 with sidepieces 57, and the shut-off member 35 for interrupting the feeding of blanks 9 are mounted on the guides 32.

The device according to the invention for feeding blanks to the die of a hot-heading press is operated as follows.

As the blank 9 (Figures 1,5) drops from the feed conveyer 46, it strikes with its front end against one of the arms of the lever 12 and starts slipping over its plane along the labyrinth 8 of the feeder bin 1. Under the weight of the blank 9 the lever 12 is turned about the pivot 11 to strike with its other arm against the tail end of the blank 9, thereby causing the latter to move toward the labyrinth 8 of the feeder bin 1, where the axis of the blank 9 is directed normally to the plane of the wheel 3.

This being done, the spring 47 is operated to return the double-arm lever 12 to its original position. The blank 9 is further moved under gravity along the inclined labyrinth 8 toward the wheel 3 and stops in the blank loading appliance 2. The maximum and minimum numbers ofthe blanks 9 is controlled by the delay-action sensors 10 in the feeder bin 1, which operate to switch on and off the drive for transferring the blanks 9 onto the feed conveyor 46. As the blank 9 enters the nest 17 in the wheel 3, it bears up against the stop 13, fixed on the housing 7 of the feeder bin 1 to prevent skewing or dropping out of the blank 9 from the feeder bin 1 and from the wheel 3. As the blank 9 is collected by the wheel 3, which is driven through one of the continuously rotating shafts 21 of the press, it starts moving together with the wheel 3 toward the heating zone "a".At the same time the blank 9 slips over the surface of the stop 13, the bearing surface 26 of which in one of the positions of the pocket 17 has a common plane of contract with its surface.

During its further movement the blank 9 finds its way into the zone of action of the means 4 for retaining blanks in the nests 17 of the wheel 3, whereupon it is engaged by the rollers 14 and 15to be thereby pressed against the corresponding magneto-conducting element 43 and 44. Under the action of the counterbalance 51, the blank 9 is placed by means of the roller 51 in the pocket 17 normally to the plane of the wheel 3 and then is pressed by the same roller against the magneto-conducting element 44. As the blank 9 is disengaged from the roller 51, it is then engaged by the roller 14 which, actuated by the spring 49, operates to press the blank 9 in an axiai direction against the magneto-conducting element 43 of the flat ring 45 (Figure 2). The blank 9 thus positioned is reliably held in place by magnetic force.As this happens, the basic flux of the magnets 36 through the plate 37, which is used as the summator of magnetic flux, and further through the air gap "b" between the plate 37 and the magnetoconducting element 43, and then through the magneto-conducting element 43, blank 9, magnetoconducting element 44, the air gap "c" between the magneto-conducting element 44 and the magnetic plate 38, as well as through the magnetic plates 38 to the other pole of the same magnets 36. To make optimal use of the magnetic force produced by the magnetic system, the air gap "b" is of minimal size.

The blanks 9, retained in place on the wheel 3 during its rotation, pass through the heater (not shown) in which the free end of each blank is heated, and then approach the means 5 adapted to remove the blanks from the wheel 3. The blank 9 is then attracted by the magnetic force of the clamp to be retained thereby.

The continuously rotating wheel 3 keeps on pushing the blank 9 along the surface of the magnetic plates 28 of the magnetic clamp. As the blank 9 moves over the surface of the magnetic plates 28, it is concurrently rolled out of the pocket 17 in the wheel 3.

In the course of further movement of the wheel 3 with the blank 9, the latter is brought in contact with the plate 30 of non-magnetic material, as a result of which the interaction between the magnetic plate 28 and the blank 9 becomes weaker to permit breaking away of the blank 9 from the magnetic clamp. Next, the blank 9 rolls out ofthe pocket 17 in the wheel 3 to get into the slipway 27 along which it is advanced to the press die through the agency of the mechanism 6.

With the blank feeding device of the invention it becomes possible to reduce the percentage of defective products in the production of industrial holders and fasteners, and to enhance production efficiency of a press by prolonging the service life of the members and units incorporated in the press gearing system due to elimination of intermittent operation of the blank feeding device and a lower flywheel mass as compared to the prior-art devices used for similar-purposes.

Claims (5)

1. Adeviceforfeeding blanks to the die of a hot-heading press, comprising a blank feeder bin, a blank loading means, a wheel geared to a press drive and having pockets arranged over its periphery to receive the blanks during their delivery in a heating zone produced by a heater mounted at one end face of the wheel, a means for retaining the blanks in the pockets of the wheel when in the heating zone, a means for removing blanks from the wheel, and a mechanism for advancing the blanks to the die press, wherein the means for retaining the blanks in the pockets of said wheel is a magnetic system including permanent magnets having their analogous poles fixed on the convex surface of an arc-shaped plate from a magnetic material to permit summation of magnetic flux, the opposite pole of each magnet being connected to a separate plate from a magnetic material to permit breaking of magnetic flux, and magneto-conducting elements with a part thereof secured on flat ring in rigid connection with said wheel and each being placed opposite the corresponding nest, the other part of said elements being fixed on the wheel so that each of said elements is arranged between the corresponding nest of the wheel and the axis of rotation of the latter, with the plate for summation of magnetic flux being positioned opposite the heater on the other side of said wheel while the arc-shaped edge of said plate is presented to the magneto-conducting element of the flat ring that is found in the heating zone and is spaced somewhat apart from said elements so as to form a gap therewith.

2. A device as claimed in claim 1, wherein the pockets provided in the wheel are slots arranged over the periphery of the wheel, the blank loading means having a stop mounted on the housing of the feeder bin and having its bearing surface, in a certain position of each slot, in contact with the surface of the latter, and a spring-loaded roller for pressing the blank against a respective magneto-conducting element positioned on the flat ring, a double-arm lever with a counterbalance being placed on one end thereof and the spring-loaded roller on the other, said roller being used for pressing each blank against a respective magneto-conducting element disposed on said wheel.

3. A device as claimed in claims 1 and 2, wherein the means for removing the blanks from the wheel has a slipway with its upper edge in abutted relationship with the generatrix of the wheel so as to be in intimate contact with the surface of the slot in said wheel at a time when the blank breaks away from the magneto-conducting elements on its exit from the heating zone.

4. A device as claimed in claim 3, wherein a magnetic clamp is provided above the slipway, said magnetic clamp having plates made of a magnetic material and a permanent magnet placed therebetween, as well as a plate from a non-magnetic material, said plate being fixed on the surface of the permanent magnet, facing the slipway and having its edge spaced in parallel relationship with the slipway.

5. A device for feeding blanks to the die of a hot-heading press, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.