APPARATUS FOR FITTING WORKPIECES FASTENING PALLETS IN A MACHINE TOOL

Abstract: The apparatus comprises a rigid, horizontal bed (5), fitted with a rotary table (11) which is adapted for rotation around a horizontal axis and provided with catch means (12, 13) for engaging one end of a pallet (14), said bed (5) being fitted at a distance from rotary table (11) and on its axial line of rotation (18) with a rotating centering plug (15) for engaging the other end of a pallet, a pallet to be replaced being fastenable between the rotary table and centering plug. As a pallet can be locked at any position around its lengthwise axis, the actual working can be effected in a more versatile fashion without removing, positioning and re-fastening of workpieces.

Description: Apparatus for fitting workpiece fastening pallets in a machine tool. A generally used fastening means for mounting pieces to be worked in a machine tool comprises a. so-called pallet, which in cross--s . ection is e.g. a quadratic, elongated element, provided on the side e.g. with T-shaped fastening grooves for fixing the pieces to be worked therein. single pallet can be fitted with a plurality of workpieces on one or more sides of a pallet. A pallet is mounted on the machine table for the period of working. In the case of e.g. a vertical spindle machine tool, the machine table can be dis¬ placed in the directions of X- and Y-axes and a spindle, rotatable around a. vertical axis and fitted with a tool, can be displaced in the direction of Z-axis or in vertical direction. If it is desired to work e.g. on the opposite sides of a workpiece, a pallet must be. released and turned over in between.. As an alternat¬ ive, the workpieces must be removed from a pallet and turned over. This removal, fitting and re-fastening requires labour and time, bringing down the capacity of a machine tool and increasing labour costs per piece. An object of the invention is to provide a novel apparatus for fitting workpiece fastening pallets in a machine tool so as to facilitate a more versatile working of the pieces without removal, positioning and re-fastening. In order to achieve this object, an apparatus of the invention.is characterized by comprising a rigid, horizontal, bed. which is fitted with a rotary table, adapted for. rotation: around a horizontal axis and pro¬ vided with catch means for engaging one end of a pallet,, said bed being fitted at a distance from the rotary table and on. the line of its axis of. rotation with a rotating centering plug for engaging, the other end of a pallet,, a palle to be replaced being fasten- able between the. rotar table and centering plug. The use of a rotary table in an apparatus o the in¬ vention facilitates rotation of a pallet around its longitudinal axis rapidly and accurately. An apparatus of the invention is particularly applic¬ able to a vertical spindle machine tool, comprising a body, horizontal crosswise guideways on the body, a carriage movable on the crosswise guideways, horizontal lengthwise guideways on the carriage, a table movable on the lengthwise guideways for supporting a pallet for fastening the pieces to be worked,, vertical guide- ways mounted on the body for vertical displacement of a rota able vertical spindle, as well as means at the spindle end for fastening a tool. When a bed of the invention, together with its rotary table and center¬ ing plug, is placed on the table of such a machine tool, the relative disposition of a tool and workpiece will be provided with another dimension of movement in addition to the normal dimensions of movement x, y and z of a machine tool. By virtue of an apparatus of the invention, a workpiece can be approached from all. three, sides with, vertical tool feed in a carefully determined direction. The five sides of a workpiece can. be machined, with just one mounting. The invention can be applied e.g.. to. the. working of a thread, if- a. shaft- to be. threaded is placed in. the apparatus instead of. a pallet and the. speed of rotat- ion of a continuously operated rotary table, is. synch¬ ronized in. view of the lengthwise movement of the machine table. The pitch of thread can. be chosen by selecting the ratio between, sai speed of. rotation and lengthwise movement. . Threads have been machined in the prior art by- employing a mechanical coupling between the driving mechanism of a :shaft to be thread¬ ed and the lengthwise feed mechanism. When employing an electrically driven rotary table, the movements must be synchronized by means of electric, synchronizat¬ ion elements. Thus, also, the ratio of operating speeds is readily adjustable. . However, the most important application of the invention is fastening of pallets to a machine tool. The invention will now be described with reference made to the accompanying drawings, in which fig. 1 shows an apparatus of the invention in sidp view and its bed in elevation. Fig. 2 shows an apparatus of the invention in connect¬ ion with a .vertical spindle machine tool, the machine tool being shown in a front, view. Fig. 3 is a side, view of the machine tool of fig. 1, fitted with an. apparatus of the invention. The apparatus shown in fig. 1 comprises a rigid, hori¬ zontal bed.5, on. top of which is mounted a rotary table 11 ro.tatable around a horizontal axis 18. As well-known, in the art,, the actual, table section of a rotary table is .mechanically, ro.tatable. and lockable at a variety of carefully determined angles. Moreover, a. rotary, table can be* contihubusly driven at. a desired speed of. rotation. In. terms of both; accuracy and support system, a particularly preferred rotary table has bee disclosed in. the Applicants 1 earlier FI Patent application No. 834866. The rotary table 11 is provided, with a compressed-air distributor 12,. whose, fixed outer rim is fitted with compressed-air hoses and the internal surface of said fixed outer rim is sealed against a rotating rim. Reference numeral 13 designates pneumatic fastening means. In the present case, said fastening- means are designed as a jaw chuck for engaging not only the end of a fastening pallet but also shorter elements that are supported only on rotary table 11, 13. If all that is desired is engagement between the pallet end and rotary table, said fastening means 13 may comprise a pneumatically operated conic seat engaging a match¬ ing conic seat at the end of a pallet, rotation around the shaft being prevented by means of a hole-plug grip between the components. In view of fastening the other end of a pallet, the apparatus is provided with a rotating centering plug 15, whose axis of rotation coincides with that 18 of rotary table 11. Also said centering plug 15 can be displaceable by means of a pneumatic cylinder in the direction of axis 18. A mounting block 19 of plug 15 can be fixed at various distances from rotary table 11. Fig. 2 shows the application of this apparatus to a vertical spindle machine tool. Upon the crosswise guideways 2 of the machine tool body 1 is mounted a transversely mobile carriage 3,. whose top surface is in turn provided with lengthwise guideways 3a.. The machine table 4. is longitudinally mobile on guideways 3. Mounted on. top of. said table 4 is a. bed.5 with- its rotary, table ' 11 and centering plug 15. A workpiece fastening pallet 14 is. secured between fastening means 12, 13 on rotary, table .11. and centering plug 15 and said pallet is. rotatable around axis 18. The machine body 1. is also fitted with, vertical guide- ways 6 for. vertically displacing a body member 7. Journalled to said body member 7 is a vertical, rotat¬ able spindle 8 whose driving means are located inside the body member 7. Inside: said body member 7 are means for controlling the x- and y-directed movements of table 4 and z-directed movements of spindle 8, as- dictated by the control commands received from a control and operating panel 10. The end of spindle 8 is provided with elements for fastening tools. tool changer 9 can be used for mounting, various tools on spindle 8. It has been possible to make the operation of a con¬ ventional vertical, spindle machine tool substantially more effective and. versatile when a pallet 14 and workpieces can, by means of rotary table 11, be turned and locked at carefully determined positions. Instead of pneumatic equipment, the fastening and re¬ lease of pallets can of course be effected by. means of hydraulic piston-cylinder units, if major fasten¬ ing forces are required, when using heavier units.

Claims: AMENDED CLAIMS [received by the International Bureau on 17 June 1985 (17.06.85); original claim 1 amended ; remaining claims unchanged (1 page)] 1. An apparatus for fitting workpiece fastening pallets (14) in a machine tool, when the fastening pallets to be fitted are elongated, many-sided pieces, the sides of which are provided with grooves or the like for fastening the pieces to be worked therein, c h a r a c t e r ¬ i z e d in that one end of the rigid, horizontal bed (5) is fitted with a rotary table (11) which comprises its own rotational drive motor and can be locked into any " specific rotational angle, the axial line of rotation (18) of which is horizontal and to the other end of which is fastened a rotating centering plug (15) which meets the said axial line of rotation (18) , and in that the ends of the fastening pallets (14) are shaped so as to grip the catch means (13) of the rotary table and the centering plug (15) , whereby the pallet (14) to be replaced can be fastened between the rotary table (11) and the centering plug (15) .

Inventors: NIEMI PERTTI KALEVI, NIEMI, PERTTI, KALEVI
Applicants: KONTINO AB OY, OY KONTINO AB
Application year: 1985
Main classification: B23Q3
IPC codes: B23Q1