IE61128B1

IE61128B1 - A method and apparatus of removing a pip from a machined component

Info

Publication number: IE61128B1
Application number: IE262588A
Authority: IE
Inventors: Charles Thomas Coughlan
Original assignee: Precision Steel R & D Limited
Priority date: 1988-08-30
Filing date: 1988-08-30
Publication date: 1994-10-05
Also published as: GB2222383A; ZA887013B; GB8915615D0; IE882625L

Abstract

The apparatus comprises a housing (10) which rotatably supports a carrier member (14) in which a plurality of locating bushes (18) are provided for locating components (3) of different sizes over a shearing blade (20) for shearing off of the pip (2). The blade (20), having a circular cutting edge (28), is eccentrically mounted on an eccentric spigot (34) of a rotating shaft (30). Each component is entered into an opening (19) in the appropriate bush (18) until the component abuts a radial surface of the blade (20). As the blade (20) rotates, due to its eccentric mounting it moves transversely across the pip (2) thereby shearing it from the component (2). The carrier member (14) may be indexed around to align different locating bushes (18) with the blade (20) to accommodate components of different sizes.

Description

The present invention relates to a method and apparatus for removing a pip from a machined component, and the invention also relates to a machined component from which the pip has been removed using the method and apparatus.

In the manufacture of machined components, it is common for a pip of stock material to remain on the component when the machining is completed. In general, the pip is formed when the component is being parted off from the stock material. This is a particular problem where components are being turned and parted off from the stock material by a parting tool. Indeed, in the mass production of turned components, for example, from capstan lathes, plug board and sequential control machines the removal of pips can present considerable difficulties and slow down the production of the components very considerably.

In general, in parting off a component from the stock material in a lathe, the parting-off tool is moved transversely through the stock material relative to its rotational axis. . However, as the parting-off tool nears the rotational axis of the stock material, the weight and inertia of the component being parted off from the stock material causes it to break off from the stock material before the parting tool has actually reached the rotational axis of the component This thus leaves a pip of material on the component which has broken off. The remaining pip on the stock material is removed as the parting-off tool reaches the rotational axis. In practice, it has been found that the resulting pip of material can vary in diameter from between 10% to 15% of the diameter of the stock material.

Once the component has been parted off with a pip remaining, the pip has to be removed. This particularly slows down the production process and also can cause damage to the machined component. In general, to remove the pip. the machined component is offered up to a grinding wheel of a grinder, normally a pedestal grinder. The grinder thus removes the pip However, unless one is particularly careful in offering up the component to the grinder, one of two problems may occur. Firstly, as well as grinding off the pip, the grinding wheel may touch part of the component, thereby removing metal from the component and causing irreparable damage. This, in general, leads to the rejection of a component. The second problem which arises in grinding off the pip is that an operator in taking care to avoid damage to the component may not fully remove the pip and accordingl the component may have to be rejected. However, even if one avoids these two problems, the production process is considerably slowed down in removing the pips.

Various attempts have been made to provide a method and apparatus for removing a pip from a component which avoids the problems of known methods and apparatus. However, so far a satisfactory method and/or apparatus has not yet been found. Indeed, the only satisfactory method and apparatus known to avoid the problem is a method and apparatus for preventing the pip being formed in the first place. Such apparatus is generally expensive and tends to slow down the production operation considerably. This method and apparatus requires the machined component to be gripped and supported prior to it being parted off from the stock. Because of the cost of this apparatus and its relative inflexibility and the fact that it tends to slow down the production operation considerably. it has, in general, been found unsatisfactory.

There is therefore a need for a method and apparatus for removing a pip from a machined component whether the component has been turned or milled or formed by any other machining process which overcomes the problem of known methods and apparatus.

The present invention is directed towards providing such a method and apparatus.

There is also a need for a machined component formed hy using the method and apparatus of the invention and the invention is also directed towards providing such a machined component.

According to the invention there is provided a method for removing from a machined face of a component a pip of the type hereinbefore described which extends from the machined face thereof, the method comprising the steps of locating the component in a locating means with the machined face of the component abutting a radial surface of a shearing blade, the radial surface of the shearing blade terminating in a cutting edge, and the cutting edge being adjacent the machined face of the component, and shearing the pip from the component by moving the shearing blade transversely of the pip axis from a first position with the cutting edge on one side of the pip to a second position with the cutting edge on the other side of the pip, the machined face of the component being in sliding engagement with the radial surface of the shearing blade and the cutting edge as the shearing blade is being moved from the first position to the second position. In one embodiment of the invention, the cutting edge of the shearing blade is just spaced apart from the pip in the first position. In another embodiment of the invention, the cutting edge of the shearing blade is just spaced apart from the pip in the second position.

Advantageously, the shearing blade is rotated.

In one embodiment of the invention, the cutting edge of the shearing blade is provided around a circular peripheral edge of the blade, and the blade is eccentrically rotated relative to its circular cutting edge.

Additionally, the invention provides apparatus for carrying out the method of the invention for removing from a machined face of a component a pip of the type hereinbefore described which extends from the machined face, the apparatus comprising a housing, a locating means provided in the housing for receiving and locating the component, a shearing blade for shearing the pip from the component, the shearing blade having a radial surface which terminates in a cutting edge and being mounted in the housing adjacent the locating means so that the radial surface abuts the machined face of the component and the cutting edge is adjacent the machined face, the shearing blade being movable in the housing transversely relative to the pip axis from a first position with the cutting edge on one side of the pip to a second position with the cutting edge on the other side of the pip.

In one embodiment of the invention, the locating means is provided by a locating opening in the housing to accommodate the component. In another embodiment of the invention, the shearing blade is movable in a plane transverse of the axis of the locating opening.

Preferably, the locating opening is disposed to permit the machined face of the component to abut a radial surface of the shearing blade. Advantageously, the locating opening defines an outer circumferential dimension of the component.

In one embodiment of the invention, the shearing blade is provided with a circular peripheral cutting edge. Advantageously, the shearing blade is rotatable about an eccentric axis relative to its circular cutting edge.

In another embodiment of the invention, a carrier member mounted on the housing is provided to carry a plurality of locating means, the carrier member being sequentially movable through a plurality of discrete locations to present each of the locating means sequentially to the shearing blade. Advantageously, the carrier member carries a plurality of locating means at spaced apart positions around a pitch circle, so that on rotation of the carrier member the locating means are sequentially presented to the shearing blade.

Further, the invention provides a machined component from which a pip of the type hereinbefore described has been removed using the method according to the invention.

The invention also provides a machined component from which a pip of the type hereinbefore described has been removed using the apparatus according to the invention.

The invention will be more clearly understood from the following description of a preferred embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a machined component with a pip, Fig. 2 is a perspective view of the machined component of Fig. 1 with the pip removed.

Fig. 3 is a perspective view of apparatus according to the invention for removing a pip from a machined component, Fig. 4 is a cut-away perspective view of the apparatus of Fig. 1, Fig. 5 is a cross sectional view of portion of the apparatus of Fig. 1, Fig. 6 is an exploded perspective view of a detail of the apparatus of Fig. 1, Fig. 7 is a cross sectional view of a detail of the apparatus of Fig. 1, and Fig. 8 is a cross sectional view of the detail of Fig. 7 in a different position.

Referring to the drawings, there is illustrated apparatus according to the invention indicated generally by the reference numeral 1 for removing a pip 2 from a machined component 3. Before describing the apparatus 1 in detail, a typical component 3 with a typical pip 2 will first be described with reference to Figs. 1 and 2. Fig. 1 illustrates the component 3 which is a machined component having been turned on a lathe from suitable mild steel stock material (not shown). The component 3 has a number of turned surfaces 4 extending between its two ends 5 and 6.

The end 5 is smooth, however, the pip 2 of mild steel material remains on the end 6 after the component 3 has been parted from the stock material. Fig. 2 illustrates the component 3 after the pip 2 has been removed.

Referring now to Figs. 3 to 8, the apparatus 1 will now be described. The apparatus 1 comprises a housing 10 of steel having a base 11 and side walls 12. A partition 13 forms two compartments in the housing 10. namely an upper compartment 7 and a lower compartment 8. The housing 10 may be mounted on any suitable support with the base 11 substantially horizontal. A carrier member 14 closes the upper compartment and is rotatably mounted on a shaft 17 extending up from the partition 13. A recess 15 at the top of the side walls 12 accommodates the carrier member 14. The carrier member 14 is provided with a plurality of openings 16 which releasably receive a plurality of locating means, namely, bushes 18. An opening 19 extends through each bush 18 to receive and locate a machined component 3 adjacent a shearing blade 20 for shearing the pip 2, as will be described below. The bushes 18 are provided in spaced apart positions and are provided on a common pitch circle, which is indicated by the broken line 21, see Fig. 3. Thus, by rotating the carrier member 14 the bushes 18 are sequentially brought adjacent the shearing blade 20.

A plurality of index recesses 23 which define index positions are provided adjacent the periphery of the carrier member 14. Each index recess 23 corresponds with a bush 18 for locating its respective bush 18 in the correct position relative to the blade 20. A locking means, in this case a pin 24 slidable in a bracket 25 which is secured to the housing 10 engages the index recesses 23. A spring 26 acting between the bracket 25 and a washer 27 fast on the pin 24 biases the pin 24 into the recesses 23. 1 As can be seen, the openings 16 in the carrier member 14 are of varying sizes to receive different sizes and shapes of bushes 18 to accommodate different shapes and sizes of components 3. The cross sectional area of each opening 19 is substantially similar to the cross sectional area of portion of the component 3, which it is to receive and locate, thereby securely locating the component 3.

It has been found preferable that the opening 19 should be of such a size that the component 3 is a reasonably tight sliding fit in the opening 19 to prevent wobble of the component during shearing. This ensures a smooth face being formed on the end 6 of the component 3 during shearing of the pip 2.

The blade 20 is provided with a circular cutting edge 28. A shaft 30 rotatable in a bearing 31 in the partition 13 eccentrically supports the blade 20 on an eccentric spigot 34 which engages a central opening 35 in the blade 20. Thus, the geometrical centre of the blade 20 co-incides with the axis of the eccentric spigot 34. A circular support disc 33 of steel for supporting the shearing blade 20 is secured to the shaft 30 and is concentric with the eccentric spigot 34. A keying pin 36 extending from the support disc 33 engages one of three corresponding keying holes 37 on the shearing blade 20 for a purpose to be described below.

The axis of the eccentric spigot 34 in this particular embodiment of the invention is offset from the rotational axis of the shaft by a distance of 1.5 mm.

The rotational axis of the shaft is indicated by the chain dotted line 40 while the axis of the spigot 34 is indicated by the chain dotted line 41, see Figs. 7 and 8. Thus, as the shaft 30 rotates, the eccentricity of rotation of the cutting edge 28 of the blade 20 is 3 mm. Accordingly, as the blade 20 is eccentrically rotated, the cutting edge 28 moves from a first position which is just spaced apart from one side of the pip 2 as illustrated in Fig. 7 to a second position illustrated in Fig. 8 where the cutting edge 28 of the blade is on the other side of the pip and just spaced apart therefrom having sheared the pip 2 off in traversing from the first to the second position.

By virtue of the fact that the blade 20 moves from a position only just spaced apart from the pip 2 on one side to the other side of the pip, portion of the blade is at all times beneath the opening 19 of the bush 18. Thus, a radial face 44 of the blade 20 always acts as a stop to abut the end 6 of the component 3 to prevent it falling through the opening 19 and to ensure that the pip 2 is correctly presented to the cutting edge 28 of the blade 20. Should the - 13 component 3 be inserted in the opening 19 when the shearing blade 20 is in the second position illustrated in Fig. 8 the pip 2 abuts the radial face 44 until the blade 20 has rotated a sufficient angular distance so that the cutting edge 28 clears the pip 2, in other words until the blade 20 has substantially moved to the first position illustrated in Fig. 7. In this position the component 3 drops further through the opening 19 until its face 6 abuts the radial face 44 of the blade 20. Further rotation of the blade 20 through 180° shears the pip 2.

The peripheral edge of the shearing blade 20 is ground at an angle as can be seen in Figs. 7 and 8 to form the cutting edge at the radial face 44. The blade 20 is mounted on the shaft 30 so that its face 44, in use, always abuts the face 6 of the component 3. This causes the pip 2 to be sheared from the component 3 adjacent the end face 6 of the component 3, in other words at the root of the pip 2.

An electric motor 38 drives the shaft 30 through a speed reduction gearbox 39. The motor 38 operates at 1,450 revs per minute, and the gearbox 39 reduces the rotational speed of the shaft 30 to 150 revolutions per minute.

A tray 47 slidably mounted in a side wall 12 of the housing 10 collects pips 2 sheared from components 3 for subsequent disposal.

In use, the carrier member 14 is rotated until the desired bush 18 is in position over the shearing blade . The locking pin 24 is engaged in the appropriate index recess 23 to finally locate and secure the carrier member 14 in position. The motor 38 is activated and the blade 20 rotated. Components 3 are then sequentially entered in the opening 19 of the bush 18 for shearing of the pip 2. On the pip 2 being sheared, the component is removed and the next component inserted in the opening 19.

When it is desired to remove the pips from a batch of different shaped and size components, the carrier member 14 is again rotated to bring the appropriate bush 18 into position over the blade 20.

When the portion of the cutting edge 28 of the blade 20 which is carrying out the shearing begins to wear, the blade 20 is rotated on the spigot 34 so that the next adjacent keying hole 37 engages the keying pin 36. This thus presents a fresh portion of the cutting edge 28 for shearing. When the blade 20 wears after the third keying hole 37 has been engaged on the pin 36, the blade 26 is then removed for resharpening and/or may be replaced by a fresh blade.

In this particular embodiment of the invention, because the eccentric rotational travel of the blade is 3 mm, the maximum pip diameter which can be accommodated is 3 mm. A greater pip diameter would prevent the pip being offered up to the blade 20. Additionally, by virtue of the fact that the eccentric travel of the blade is 3 mm the apparatus is effectively only suitable for components the largest diameter adjacent the pip of which is greater than 3 mm. Otherwise, there is a danger that the radial face 44 of the blade 20 would not act to stop the component falling through the opening 19 and accordingly the blade 20 could also shear off portion of the component. In practice, it has been found that the minimum diameter of component should be at least 4 mm. However, as mentioned above, where it is desired to remove a pip form components of smaller diameter, the shaft 30 may be replaced with a shaft having a spigot the eccentric offset of which is less than 1.5 mm.

While the apparatus has been described as comprising an eccentrically mounted rotating shearing blade, any other suitable shearing blade could be used. Indeed, in certain cases, it is envisaged that a reciprocating shearing blade may be provided. It will also be appreciated that while the blade has been mounted on an eccentric spigot the axis of which is displaced 1.5 mm from the rotational axis of the shaft, the eccentric offset could be greater or lesser as desired. Indeed, for very small components where the pip would be of a relatively small diameter, it is envisaged that the offset may be as low as 0.5 mm or even less. It will be appreciated that where the offset is 0.5 mm the eccentric travel of the blade would be 1 mm, thereby just sufficient to remove 1 mm diameter pip.

Needless to say, other shapes and constructions of shearing blade may be used besides that described. It will also of course be appreciated that while it is preferable to have the shearing blade mounted so that it can be rotated about its own axis to present different portions of the cutting edge for shearing purposes, this is not necessary. Indeed, more or less than three different positions could be provided in certain cases if desired.

It will also of course be appreciated that while a particular shape, size and construction of component has been described for use with the apparatus, the apparatus could be used for removing the pip from any shape, size or construction of component. Indeed, it will be appreciated that the apparatus could also be used for removing the pip from a milled component or a component formed by any other machining process.

While the apparatus has been described as comprising a rotatable carrier member, any suitable carrier member for carrying the locating means could be provided. Indeed, in certain cases, it is envisaged that the carrier member could be dispensed with altogether and the locating means could be provided in the housing.

In which case, a single locating means would be provided. Alternatively, where a plurality of locating means are desired, it is envisaged that the locating means may be provided on a linearly movable carrier member. Needless to say, other suitable indexing means besides that described could be used if desired without departing from the scope of the invention.

While the locating means have been described as being provided by a bush or bushes mounted in the carrier member, any other suitable locating means could be provided. Indeed, in certain cases it is envisaged that the locating means need not completely embrace the component, they may only partly embrace the component. Further, it is envisaged that the locating means could be provided by any suitable type of jaws, such as clamping jaws or the like. Further, the locating means may be provided by openings in the carrier member or an opening in the housing.

Although not illustrated and described, it is envisaged that a suitable feeding mechanism could be provided for automatically feeding the components into the locating means and similarly automatic removing means could also be provided.

Needless to say, if desired the tray may be dispensed with.

While the rotational speed of the blade has been described as 150 revolutions per minute, it is envisaged that the shaft may rotate at any rotational speed, however, it has been found that optimum results are obtained when the rotational speed of the blade is in the range of 50 to 450 revolutions per minute.

While the method for removing the pip from the component has been described with reference to a particular construction of apparatus, any other suitable apparatus could be used without departing from the scope of the invention provided the method includes shearing the pip from the component by moving a shearing blade from one side of the pip to the other side transversely of the axis of the pip with the machined face of the component in sliding engagement with the radial surface of the shearing blade and the cutting edge as the shearing blade is being removed from the first position to the second position.

Claims

1. A method for removing from a machined face of a component a pip of the type hereinbefore described which extends from the machined face thereof, the

2. A method as claimed in Claim 1 in which the cutting edge of the shearing blade is just spaced apart from the pio in the first position.

3. A method as claimed in Claim 1 or 2 in which the 25 cutting edge of the shearing blade is just spaced apart from the pip in the second position.

4. A method as claimed in any preceding claim in which the distance between the first and second positions of the cutting edge of the shearing blade is up to 5 mm. 5. Method according to any of Claims 1 to 12. 33. A machined component from which a pip has been removed using apparatus according to any of Claims 13 to 31. 34. A machined component from which a pip has been 10 removed using the method according to any of Claims 1 to 12 and the apparatus according to any of Claims 13 to 32. 35. A machined component substantially as described herein with reference to and as illustrated in the 5 eccentric offset between the two axes is up to 1.5 mm. 22. Apparatus as claimed in any of Claims 19 to 21 in which the shearing blade rotates at a speed in the range of 50 to 450 revs per minute. 23. Apparatus as claimed in Claim 22 in which the 10 shearing blade rotates at a speed of 150 revs per minute. 24. Apparatus as claimed in any of Claims 13 to 23 in which the locating means receives and locates the component with the axis of the pip substantially 15 vertical. 25. Apparatus as claimed in any of Claims 13 to 24 in which a carrier member mounted on the housing is provided to carry a plurality of locating means, the carrier member being sequentially movable through a 20 plurality of discrete locations to present each of the locating means sequentially to the shearing blade. 26. Apparatus as claimed in Claim 25 in which the carrier member carries a plurality of locating means at spaced apart positions around a pitch circle, so that on rotation of the carrier member the locating means are sequentially presented to the shearing blade. 27. Apparatus as claimed in Claim 26 in which the carrier member is rotatable through a plurality of index positions, each index position corresponding to a respective locating means and a locking means being provided to lock the carrier member in the respective index positions. 28. Apparatus as claimed in any of Claims 25 to 27 in which the locating means are of different sizes to accommodate different sizes and shapes of components. 29. Apparatus as claimed in any of Claims 25 to 28 in which the carrier member is provided with a plurality of locating openings to releasahly receive and retain the locating means. 30. Apparatus as claimed in any of Claims 13 to 29 in which a tray is provided in the housing to collect a pip removed from a component. 31. Apparatus for removing a pip of the type hereinbefore described from a machined component, the apparatus being substantially as described herein with reference to and as illustrated in the accompanying drawings. 32. A machined component from which a pip of the type hereinbefore described has been removed using the 5 15. Apparatus as claimed in Claim 14 in which the shearing blade is movable in a plane transverse of the axis of the locating opening. 15. Apparatus as claimed in Claim 15 in which the locating opening is disposed to permit the machined 5 distance between the first and second positions of the cutting edge of the shearing blade is up to 3 mm.

5. A method as claimed in Claim 4 in which the 5 method comprising the steps of: locating the component in a locating means with the machined face of the component abutting a radial surface of a shearing blade, the radial surface of the shearing blade terminating in a cutting edge, and the

6. A method as claimed in any preceding claim in which the axis of the pip on the component is vertically aligned, the transverse movement of the blade being in

7. A method as claimed in any preceding claim in which the shearing blade is rotated.

8. A method as claimed in Claim 7 in which the cutting edge of the shearing blade is provided around a 15 circular peripheral edge of the blade, and the blade is eccentrically rotated relative to its circular cutting edge.

9. A method as claimed in Claim 8 in which the shearing blade is rotated at a speed in the range of 50 20 to 450 revs per minute. 10. Face of the component to abut a radial surface of the shearing blade. 17. Apparatus as claimed in Claim 15 or 15 in which the locating opening defines an outer circumferential dimension of the component. 15 18. Apparatus as claimed in any of Claims 15 to 17 in which the shearing blade is provided with a circular peripheral cutting edge. 19. Apparatus as claimed in Claim 18 in which the shearing blade is rotatable about an eccentric axis 20 relative to its circular cutting edge. 20. Apparatus as claimed in Claim 19 in which the eccentric offset of the rotational axis of the shearing blade from the geometrical axis of the circular cutting edge is up to 2.5 mm. 21. Apparatus as claimed in Claim 20 in which the

10. A method as claimed in Claim 9 in which the shearing blade is rotated at a speed of 150 revs per minute. 10 a plane perpendicular to the vertical axis of the pip. 10 cutting edge being adjacent the machined face of the component, and shearing the pip from the component by moving the shearing blade transversely of the pip axis from a first position with the cutting edge on one side of the 15 pip to a second position with the cutting edge on the other side of the pip, the machined face of the component being in sliding engagement with the radial surface of the shearing blade and the cutting edge as the shearing blade is being moved from the first 20 position to the second position.

11. A method as claimed in any preceding claim in which the pip removed from a component is collected in a tray.

12. A method for removing a pip of the type hereinbefore described from a machined component, the method being substantially as described herein with reference to and as illustrated in the accompanying drawings .

13. Apparatus for carrying out the method of any of Claims 1 to 12 for removing from a machined face of a component a pip of the type hereinbefore described which extends from the machined face, the apparatus comprising a housing, a locating means provided in the housing for receiving and locating the component, a shearing blade for shearing the pip from the component, the shearing blade having a radial surface which terminates in a cutting edge and being mounted in the housing adjacent the locating means so that the radial surface abuts the machined face of the component and the cutting edge is adjacent the machined face, the shearing blade being movable in the housing transversely relative to the pip axis from a first position with the cutting edge on one side of the pip to a second position with the cutting edge on the other side of the pip.

14. Apparatus as claimed in Claim 13 in which the locating means is provided by a locating opening in the housing to accommodate the component.

15. Accompanying drawings.