| EP0036506A1 | 1981-09-30 | |||
| US4221514A | 1980-09-09 |
| 1. | An apparatus for shearing off the center stub (9) remaining in the parting turning of a metal piece (5) , c h a r a c t e r i z e d in that said apparatus comp¬ rises a slide (2) movable into a shearing position with the power of an actuator (7) , said slide having a smooth work surface (10) adapted to act as an abutting surface for the turned parting surface of said metal piece (5) , said work surface further having dropped below the sur¬ face a recess (8, 8') suited to accommodate the stub to be sheared off, and a stub shearing blade (3) , said blade being aligned essentially flush with said work surface for the purpose of shearing off said stub, and that said apparatus further has a backgage (4) for backing the metal piece during the cleanshearing of its stub. |
| 2. | An apparatus as defined in claim 1, c h a r a c ¬ t e r i z e d in that the apparatus has an upper gage (11) for clamping the metal piece against the work surfa¬ ce (10) . |
| 3. | An apparatus as defined in claim l or 2, c h a r ¬ a c t e r i z e d in that the work surface (10) of the slide (2) is aligned slightly upward slanting toward the blade (3) in the movement direction of the slide?". |
| 4. | An apparatus as defined in claim 1, c h a r a c ¬ t e r i z e d in that the recess (8, 8') dropped below said work surface (10) comprises a groove (8) aligned parallel to the movement of the slide (2) . |
| 5. | An apparatus as defined in any of foregoing claims 14, c h a r a c t e r i z e d in that said slide (2) is adapted to run its work stroke in an essentially hori¬ zontal plane. |
| 6. | An apparatus as defined in any of foregoing claims 14, c h a r a c t e r i z e d in that said slide (2) is adapted to run its work stroke in an essentially ver¬ tical plane. |
The present invention relates to a cut-off device, also called a clean-shear apparatus, for removal of the center stub or nipple which remains in parting-turning on the end of the parting-turned object when the object is parted from bar stock by parting-cutting with a parting tool. Conventionally, the center stub has been removed by, e.g., grinding using a bench or belt sander. Such a workstep is relatively slow, because grinding is not a particularly effective method in comparison with clean- shearing. The center stub of rather small diameter causes a point of highly concentrated surface pressure on the grinding equipment which causes rapid wear of the bonded abrasive. During grinding, it is awkward to assess the completeness of stub removal, whereby high quality of the end result is difficult to attain. Moreover, the method is slow, noisy and dusty. The art is also lacking an ap¬ paratus particularly suited for this use.
The apparatus according to the invention removes stubs very quickly and accurately, and further, requires no special skills. If extremely high requirements are set for the surface quality at the parting point, the stub is advantageously removed using this kind of apparatus, af¬ ter which the fine finishing in a manner that gives the surface a finish which is compatible with the quality requirements. Also a counter indicating the number of processed objects may be connected to the apparatus. The apparatus is capable of machining objects of revolution with varied shape and size.
The particulars of the apparatus according to the inven¬ tion are disclosed in the annexed claim 1. Other embodi- ments of the invention are defined in the dependent claims related to claim 1.
In the following the invention will be examined with re-
ference to the appended drawings, in which
Figure 1 is a view of a simplified basic embodiment of the apparatus according to the invention; and
Figure 2 is a view of another embodiment of the apparatus according to the invention.
Referring to Fig. 1, the apparatus shown therein comp- rises a body 1 having a slide groove acting as a guide for a slide 2. The slide 2 is provided at its one end with an actuator 7 that imparts a reciprocating work movement for the slide. Such an actuator may be, e.g., a double-acting pneumatic cylinder or a hydraulic, electri- cal or mechanical actuator capable of performing an equi¬ valent movement action. In the embodiment illustrated in the drawing figure, the slide is provided with a work surface 10, which forms an abuttment surface for the end surface of a metal piece 5 being handled, the work sur- face being machined to include a groove 8 with suffi¬ ciently large dimensions to accommodate the stub 9 when the metal piece 10 is placed on the work surface 10. The groove is aligned parallel to the work movement of the slide, and its one end is provided with a blade 3 adapted to shear off the stub. The opposite end of the groove 8 is blocked by a backgage 4 which supports the metal piece during the clean-shearing of the stub. The backgage 4 may be equipped with a slide movement activating sensor 6 which starts the work movement of the slide when the metal piece 5 is pushed against the sensor.
Referring to Fig. 2, another embodiment of the invention is shown in a side view having the slide, and correspond¬ ingly, also the body longitudinally sectioned along the groove. In this embodiment the slide 2 is implemented differently from that shown in Fig. 1 in that the work surface of the slide 2 is aligned at a small angle from
horizontal so that the surface is slightly slanted upward toward the blade 3 in the movement direction of the sli¬ de. This nonhorizontal alignment of the surface provides a gentle wedging action which tends to press the metal piece 5 being handled against an upper gage 11.
The latter embodiment described above offers an improved support for the metal piece 5 being handled, particularly in the axial direction of the metal piece, by means of the above-mentioned axially acting upper gage 11. This support means clamps the workpiece being handled against the work surface of the slide and thus effectively pre¬ vents the workpiece from jumping loose during the clean- shearing of the stub 9. The reversible movement of the upper gage may be provided by equipping the apparatus with a pneumatic cylinder 12.
In the diagrams the apparatus is shown designed for a horizontal movement of the slide 2. However, without de- parting from the scope of the invention, the apparatus may also be designed so that the slide 2 is vertically movable, whereby the workpiece 5 being handled is aligned horizontal. In the latter embodiment, the support of the workpiece 5 being handled can be implemented with simple means.
Further without departing from the scope of the inventi¬ on, the above-described linear movement of the slide can be replaced by a rotational movement, either using a re- ciprocating swing motion or a unidirectional rotational motion.