GB2035865A

GB2035865A - Feed apparatus for wire or strip processing machines

Info

Publication number: GB2035865A
Application number: GB7938401A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-11-24
Filing date: 1979-11-06
Publication date: 1980-06-25
Also published as: IT7953753V0; DE2850944C2; FR2442087A2; FR2442087B2; DE2850944A1; BR7907624A; GB2035865B; IT1119540B; IT7969267A0

Abstract

An eccentric drive has a drive plate 101 rotatable about a first axis 102, an eccentric pin 103 fixed thereon, and a cam plate 104 fixed on the plate 101. A connecting rod 107 has cam followers 108, 109 engaging the cam plate 104, and is slidable about the axis 114. The cam plate 104 can be fixed in various positions of rotation on the drive plate 101, and the direction of displacement of the cam followers 108, 109 relative to the axis 114 can be adjusted to different directions B-B relative to the direction of movement A-A of the rod 107. Such movement causes feed of the wire or strip which is non-simple-harmonic, motion due to the cam and followers being superimposed on that due to the eccentric drive, the motion due to the cam being adjustable in phase. <IMAGE>

Description

SPECIFICATION Feed apparatus for material draw-in for machines or apparatus The invention relates to a feed apparatus for the draw-in of material in wire and strip treating machines, with a draw-in transporter, which is reciprocatable between two end positions, comprising a drive disc which rotates at a substantially constant angular speed, a first drive member arranged eccentrically on the drive plate, a second drive member which can rotate, with the first drive member and on a closed path of travel, round the axis of rotation of the drive plate and, also, is rotatable about the first drive member, and, in the course of this rotation, the distance of the second drive member from the axis of rotation of the drive plate periodically alters between a maximum value and a minimum value, and a coupling device which connects the second drive member to the draw-in transporter, the first drive member being constituted as a cam plate which, in operation, is secured to the drive plate, and the second drive member is a cam follower held in engagement with the cam plate, this cam follower rotating, for each rotation of the first drive member about the axis of rotation of the drive plate, once about the cam plate, and being, for this purpose, capable of rotary movement about an axis which, in operation, is fixed relative to the drive plate, and being displaceable relative to this fixed axis, and the cam plate has a threelobed contour which is so shaped that the pattern, plotted against time, of a component of movement, serving to drive the draw-in transporter, of the second drive member has a steeper gradient in the flank region relative to the directionally corresponding strictly sinusoidal pattern of the component of movement of a fixed point of the cam plate, although it is flattened off in the crest region.

A feed apparatus of this kind is the subject matter of co-pte, is altered, so as to enable another feed length to be set, the cam plate and the guidance of the ject of enabling the time pattern of the component of movement, serving to. drive the draw-in transporter, of the second drive member to be varied while the same cam plate is maintained.

According to the invention this object is achieved by arranging for the cam plate to be susceptible of fixing in different rotary positions on the drive plate, and for the direction of displacement of the cam follower to be adjustable, relative to the axis which is fixed relative to the drive plate, to different directions relative to the direction of movement of the draw-in transporter.

In the earlier application, the path of travel achieved by means of the cam plate can be represented as a superimposition of a sinusoidal path of travel, such as would be obtained with a circular control or camming surface of the cam plate, and of an additional component of movement which depends on how this control or camming surface of the cam plate differs from circularity.

In order that an optimal path of travel may be obtained, the amplitude, corresponding to eccentricity, of the sinusoidal path of travel, and the amplitude of the additional path of movement, must bear a specified mutual relationship. Underlying the solution according to the invention is the concept that, of the additional movement derived from the cam plate, a component which is greater or smaller according to the setting used on each occasion is to be transmitted, as additional component of movement, to the connecting rod, and hence to the draw-in slide. In the case of the feed apparatus described in the earlier patent application the cam follower is fixed to the connecting rod head.The connecting rod head is guided, by means of a slide block guidance means, rectilinearly in its longitudinal direction, so that a periodic alteration, depending on the curve shape, between the axis of symmetry, lying parallel to the axis of rotation of the drive plate, of the cam plate, and a hypothetical centre axis, lying parallel to this, of the connecting rod head will be fully transmitted to the draw-in slide. If the direction of the rectilinear guidance of the connecting rod head, and hence of the cam follower fixed to the connecting rod head, is turned relative to the longitudinal direction of the connecting rod, only a fraction of the movement of the cam follower occuring in this direction will be transmitted to the draw-in slide.This fraction equals the cosine of the angle between the longitudinal axis of the connecting rod and the direction in which the cam follower is displaceably guided. If this angle reaches 90 , that is to say if the cam follower is rectilinearly guided, relative to the cam plate, in a direction extending perpendicularly of the longitudinal axis of the connecting rod, the cam plate will no longer exert any appreciable effect on the path of travel of the draw-in slide.

In addition to the fact that the direction of rectilinear guidance of the cam follower can be altered, in the case of the solution proposed according to the invention, the rotary position of the cam plate must also be susceptible of alteration relative to the drive plate, so that it may be ensured that the sinusoidal path of travel, and the additional component of movement derived from the cam plate, may have the correct mutual position.

If, in the case of the feed apparatus according to the invention, the eccentricity, that is to say the distance of the first drive member from the axis of rotation of the drive plate, is altered, so as to enable another feed length to be set, the cam plate and the guidance of the cam follower can, in the way explained, also be so adjusted that, again, the optimal relationship of the amplitude of the sinusoidal path of travel to the amplitude of the additional component of movement will be obtained. The adjustability, realizable with simple means, of cam plate and cam follower guidance affords the appreciable advantage that only one cam plate is required for substantially all possible eccentricities.

There may be provided, for guiding the cam follower, two guide parts, which can be shifted rectilinearly relative to one another and which engage one in the other, one of which is held, on the drive plate or on the cam plate, so as to be capable of rotary movement about the axis which is fixed with respect to the drive plate, while the other guide part is connected to the cam follower. As one of the guide parts is in any case capable of rotation about this fixed axis, only the other guide part needs to be adjusted on the occasion of an alteration of the guidance direction. When we are concerned with the guide part connected to the cam follower, this guide part will preferably comprise a flange which can be fixed to a connecting member which at least partially establishes the guiding connection between cam follower and draw-in slide.As in the case of the feed apparatus of the earlier patent application the connecting member may for example be constituted as a connecting rod, whose head may, in this case, be annular so that it can be fixed to the flange of one of the guide parts. Relative turning movement between flange and connecting rod head can be infinitely variable if, for example, one of the two parts comprises arcuate slots, through which pass clamping screws in the other of the two parts. However, instead of infinitely variable adjustability, a stepwise adjustability may be realized by arranging for the connecting rod head and the flange to be connectable, by means of respective sets of teeth, in different relative rotary positions, and locked in these selected positions.Analogously, the cam plate could be provided with internal teeth and positioned on a pin, provided with a complementary set of outer teeth, so as to be fast in rotation with this pin. These sets of teeth could be selected so as to correspond to the required fineness of adjustment.

An embodiment of the invention is described below with reference to the accompanying drawings. In these drawings: Figure 1 is a schematic, plan view of the known feed apparatus; Figure 2 is a similar view of the apparatus according to the invention; Figure 3 is a schematic, cross-section taken along line Ill-Ill of Fig. 2; and Figure 4 is a schematic, cross-sectional view taken along line IV-IV of Fig. 2.

In Fig. 1, 1 designates a drive plate, which is mounted on a shaft (not shown), and is generally driven synchronously with the drive of the machine or apparatus associated with the feed apparatus. The axis of rotation of the drive plate 1, extending perpendicularly of the plane of the drawing, is indicated as 2. An eccentric pin 3 is fixed to the plate 1 at the distance of the eccentricity E, and a cam plate 4 is fixed to this eccentric pin 3 and is fast in rotation with it. A slide block 5 is rotatably mounted, above the cam plate 4, on the eccentric pin 3, and is held by a disc 6. The connecting rod 7 connects two rollers 8 and 9, which engage the cam plate 4, to a drawin slide 10.The head 7 of the connecting rod 7 so receives the slide block 5, in a recess 12, that the connecting rod head 7', and with it the rollers 8 and 9, are guided for rectilinear sliding movement, relative to the cam plate 4, in the direction of the longitudinal axis A-A of the connecting rod 7. If neither of the rollers 8 and 9 is resiliently fixed to the connecting rod head 7', the cam plate 4 must be constituted as a constant-diameter cam plate. However, even if this is the case, it is desirable to attach one of the rollers resiliently for the purpose of compensating for manufacturing tolerances.

As is described in the earlier co-pending patent application, a revolution of the drive plate 1 causes the cam plate 4 to turn about the axis 2 of rotation of the cam plate 1.

As the control or camming surface of the cam face 4 differs from circularity, the distance e of the point 13 of the connecting rod head 7', lying in the centre between the two rollers 8 and 9, from the axis 14 of the eccentric pin 3~this axis 14 coincides with the axis of symmetry of the cam plate 1 al- ters periodically. The amplitude of this periodic alteration of the distance e depends on the shape of the camming surface of the cam plate 4. This amplitude is independent of the eccentricity E.

In Fig. 1 a feed slide 35 is indicated by dashed lines, and is slidably guided in the direction of the double arrow 36 by guide means which are not shown. This feed slide 35 can pivot, together with a bearing body 38, about the axis 37, and is guided, for limited sliding movement, on the connecting rod 7, and is supported by helical compression springs 39.

Fig. 2 shows an embodiment of the invention in a schematic view similar to that of Fig.

1. The elements which correspond to those of Fig. 1 are indicated in Figs. 2 to 4 by the corresponding reference symbols increased by 100. Analogously to the drive plate 1 of Fig.

1, the drive plate 101 is drivable at a substantially constant angular speed. The connection of the connecting rod 107 to the draw-in slide is not shown in Fig. 2. Also, a direct connection, which is shown in Fig. 1, is not mandatory. For example, the connecting rod 107 could be connected to an intermediate lever, and the latter connected to the draw-in slide. The connecting rod head 107' is annular and is connected to the flange of a guide part 100. The guide part 100 has a recess 112 for receiving a slide block 105 which, in this instance, lies under the cam plate 104.

The two rollers 108 and 109 are so fixed to the guide part 100 that they can roll along the periphery of the cam plate 104. The connection between the connecting rod head 107' and the guide part 100 is adjustable.

For this purpose screws 11 5 engage in flange parts 100' of the guide part 100 and pass through arcuate slots 116 in the connecting rod head 107'. When the screws 115 are screwed tight, the connecting rod head 107' and the guide part 100 are locked together, so that they are fast in rotation with one another. When the screws 115 are unscrewed, the connecting rod head 107' and the guide part 100 can be turned relative to one another in the vicinity of the slots 11 6 and can be locked together again in some other position.

In the view as illustrated in Fig. 2 the guide part 100 has been so turned, relative to the connecting rod head 107', that the longitudinal axis of the recess 11 2 coincides with a line B-B, which includes an angle ss with the longitudinal axis A-A of the connecting rod 107. As the slide block 105 is in any case so mounted on the pin 103 as to be capable of rotary movement, its position is automatically adjusted when the position of the guide part 100 is altered.

Not only has the guide part 100~and, hence, also the recess 112, which receives the slide block 105~been turned, in the case of the embodiment of the invention shown in Fig. 2, relative to the form of construction shown in Fig. 1, but the cam plate 104 also assumes a different rotary position, relative to the drive plate 101, about its axis 114 of symmetry in comparison with the position shown in Fig. 1. The cam plate 104 has a bore 117 provied with internal toothing. The eccentric pin 103 has, at least in the vicinity of the cam plate, a complementary external toothing, so that the cam plate 104 can be mounted on the eccentric pin 103 in various rotary positions, so as to be fast in rotation with this eccentric pin 103.

When, in the arrangement shown in Fig. 2, the drive plate 101 rotates about its axis 102 of rotation, the engagement of the rollers 108 and 109 with the cam plate 104 causes the slide block 105 to move back and forth, in the recess 112 and relative to the guide part 101, along the line B-B. This movement in the direction of the line B-B can be resolved into two components, one of which components lies in the direction of the longitudinal axis A-A of the connecting rod 107 and is obtained by multiplication by the factor cos ss.

The other component lies perpendicularly of the longitudinal axis of the connecting rod 107. The latter component of movement makes no contribution to a movement of the connecting rod 107 in the direction of its longitudinal axis A-A; this contribution is made solely by the first-mentioned component of movement.

It will be readily understood that, if the same conditions obtain in the case of the arrangement shown in Figs. 1 and 2, the effect of an additional component of movement on the basis of the cam plate 104 is reduced, in the case of the embodiment of Fig. 2 by the factor cos ss in comparison with the embodiment shown in Fig. 1.

By, first, adjusting the guide part 100 relative to the connecting rod head 107' and, secondly, by adjusting the cam plate 104 relative to the eccentric pin 103, any desired value between 0 and 90 can be set for the angle ss in the case of the arrangement shown in Fig. 2. At 0 the amplitude of the additional component of movement (travel) derived from the cam plate, is a maximum, and the amplitude is zero at 90 . In this way it is readily possible to accommodate the amplitude of the additional component of movement of the value of eccentricity E, which has been set at any given time, without exchanging the cam plate.Adjustment of the cam plate 104 in addition to adjustment of the guide plate 101 is necessary to ensure, for all settings of the guide part 100, the correct phase relationship between the sinusoidal path of movement and the additional path of movement.

Figs. 3 and 4 are cross-sectional, elevational views, taken along lines Ill-Ill and IV-IV respectively of Fig. 2, and are provided for explaining one possible form of construction of the invention. In Figs. 3 and 4, 118 designates the shaft which carries and drives the drive plate 101. A slide 119 can, in a manner known per se, be slid in the drive plate 101 and locked in any desired place within the range of sliding movement. The eccentricity E, that is to say the distance between the axis 102 of rotation of shaft 118 and. of drive plate 101, and the axis 114 of the eccentric pin 103, can be selected by altering the position of the slide 119. The eccentric pin 103 is fixed to the slide 119.

The slide block 105 is rotatably mounted, above the slide 119, on the eccentric pin 103. Above the slide block 105 the cam plate 104 is mounted, by means of teeth 120, on the eccentric pin 103 so as to be fast in rotation with the latter. The cam plate 104 is secured to the eccentric pin 103 by means of a disc 121 and of a screw 122. Alteration of the position of the cam plate 104 relative to the drive plate 101 can easily be effected by unscrewing the screw 122, pulling the cam plate 104 away from the eccentric pin 103, and replacing the cam plate 104 in another rotary position about the axis 114. Only discrete rotary positions of the cam plate 104 can be set by virtue of the fact that teeth are used. If a stepless adjustment of the rotary position is desired, other, suitable methods of attachment may be selected.

The connecting rod head 107' is annular, and has a centring shoulder 123, which engages behind flange portions 100' of the guide part 100. Due to the above-described attachment of the guide part 100 to the connecting rod head 107' a continuous mutual positional adjustment is possible. Alternatively, these two parts could engage in one another by means of complementary sets of teeth.

The rollers 108 and 109 are suitably fixed, on the guide part 100, so that they can rotate about their own axes. One of the rollers can be mounted in a resilient sleeve 124 for compensating manufacturing tolerances in the cam plate. If provision is made, through suitable biasing means, for a roller, fixed to the guide part 101, to continuously engage the cam plate 104, then a single roller could be used instead of two rollers. In this case the cam plate 4 does not have to be constituted as a constant-diameter cam.

In the above description the direction in which the rollers 108 and 109 are guided for rectilinear movement relative to the cam plate is relative to the longitudinal axis A-A of the connecting rod 107. Naturally, this direction could equally well be related to the direction of movement of the draw-in slide, especially as the invention is not restricted to a connecting rod for transmitting movement from the rollers, serving as cam followers, to the drawin slide.

Claims

1. Feed apparatus for material draw-in in wire and strip processing machines, with a draw-in transporter, which is reciprocatable between two end positions, comprising a drive plate which rotates at a substantially constant angular speed, a first drive member arranged eccentrically on the drive plate, a second drive member which is rotatable, with the first drive member and on a closed path of travel, about the axis of rotation of the drive plate and is also rotatable about the first drive member and, in the course of this rotation, periodically alters its distance, between a maximum value and a minimum value, from the axis of rotation of the drive plate, and a coupling device which interconnects the second drive member with the draw-in transporter, the first drive member being constituted as a cam plate which, in operation, is secured on the drive plate, and the second drive member is a cam follower held in engagement with the cam plate, this cam follower rotating, for each rotation of the first drive member about the axis of rotation of the drive plate, once about the cam plate, and the cam follower being rotatable, on the drive plate, about an axis which is, in operation, fixed relative to the drive plate, and being slidable relative to this fixed axis, and the cam plate has a three-lobed contour which is so shaped that the pattern, plotted against time, of a component of movement, serving to drive the draw-in transporter, of the second drive member increases in gradient, relative to the directionally corresponding, strictly sinusoidal pattern of the component of movement of a fixed point of the cam plate, in the flank area, and flattens off in the crest area, wherein the cam plate can be fixed in various positions of rotation of the drive plate, and the direction of displacement of the cam follower relative to the axis which is fixed with respect to the drive plate can be adjusted to different directions relative to the direction of movement of the draw-in transporter.

2. Feed apparatus according to claim 1, wherein for the slidable guidance of the cam follower there is provided two guide parts, one of which engages in the other and which can be slid rectilinearly relative to one another, one of which guide parts is held on the drive plate or on the cam plate in such a way as to be rotatable about the axis which is fixed relative to the cam plate, while the other guide part is connected to the cam follower.

3. Feed apparatus according to claim 2, wherein said one of the guide parts is a slide block received in a recess of said other guide part.

4. Feed apparatus according to claim 2 or claim 3, wherein said other guide part has a flange which can be fixed, in different relative rotary positions, to the connecting member of the coupling device.

5. Feed apparatus according to claim 4, wherein the flange can be fixed on the annular head of a connecting rod which serves as connecting member.

6. Feed apparatus according to claim 5, wherein the head of the connecting rod and the flange can be connected to one another, by means of respective sets of teeth, in different relative rotary positions, and locked in these rotary positions.

7. Feed apparatus according to any one of claims 2 to 6, characterized in that the cam follower consists of two rollers which lie substantially diametrically opposite one another and are fixed to said other guide part.

8. Feed apparatus according to any one of claims 1 to 5 and 7, wherein the cam plate is formed with internal toothing and is placed on a pin provided with a complementary external toothing, on the drive plate.

9. Feed apparatus according to any one of claims 1 to 5 and 7, wherein the rotary position of the cam plate relative to the drive plate, and the guidance of the cam follower is steplessly adjustable.