US3650133A

US3650133A - Longitudinal carriage drive for co-ordinates tables in machine tools, particularly punching machines

Info

Publication number: US3650133A
Authority: US
Inventors: Walter Bredow
Original assignee: C Behrens AG
Current assignee: C Behrens AG
Priority date: 1968-09-17
Filing date: 1969-09-03
Publication date: 1972-03-21
Anticipated expiration: 1989-03-21
Also published as: GB1251113A; DE1777180A1; DE1777180C3; DE1777180B2

Abstract

A longitudinal carriage drive for co-ordinates tables in machine tools for impelling the carriages on co-ordinates tables, particularly the longitudinal carriage, with the transverse carriage moving thereupon transversely to the longitudinal axis of the machine, and to the material to be punched held fast thereto, in which a power transmission by two screw-threaded spindles is provided to the left and right of the center of the machine, which receive their drive synchronously from a motor arranged at about the middle of the table.

Description

United States Patent Bredow [451 Mar. 21, 1972 [54] LONGITUDINAL CARRIAGE DRIVE FOR CO-ORDINATES TABLES IN MACHINE TOOLS, PARTICULARLY PUNCHING MACHINES [72] Inventor: Walter Bredow, Alfeld an der Leine,

Germany [73] Assignee: C. Behrens Aktlengesellschait,

sl n sr. .i i9 many [22] Filed: Sept. 3, 1969 [21] Appl. No.: 854,851

[30] Foreign Application Priority Data Sept. 17, 1968 Germany ..P 17 77 180.1

[52] U.S. Cl ..72/l, 72/419, 83/409 [51] Int. Cl. ..B2ld 55/00, B2ld 43/00, 826d 7/06 [58} Field of Search ..72/1, 419; 83/409; 226/] l,

[56] References Cited UNITED STATES PATENTS 2,887,914 5/1959 Zeunert ..72/] 2,901,245 8/1959 Hensley ....83/409 X 3,330,175 7/ 1967 Bridges ....83/409 X 3,391,840 7/1968 King ....226/l1 3,429,491 2/1969 Windley ..226/|1 Primary Examiner-Charles W. Lanham Assistant Examiner-R. M. Rogers Attorney-Holman &. Stems ABSTRACT A longitudinal carriage drive for co-ordinates tables in machine tools for impelling the carriages on co-ordinates tables, particularly the longitudinal carriage, with the transverse carriage moving thereupon transversely to the longitudinal axis of the machine, and to the material to be punched held fast thereto, in which a power transmission by two screwthreaded spindles is provided to the left and right of the center of the machine, which receive their drive synchronously from a motor arranged at about the middle of the table.

3 Claims, 3 Drawing Figures PATENTEBMARZ] I972 3,650,133

sum 1 OF 3 lnrenfar:

6004 nm B/FEDa w PATENTEUMARZI I972 SHEET 2 OF 3 lnrenlonw 4 rat BREW 04 PATENTEUMMI I972 SHEET 3' [1F 3 lilllllll k lnren/ar: LUALTER BREDaw 37., k (T /M7 ATTDRA/EYS LONGITUDINAL CARRIAGE DRIVE FOR CO- ORDINATES TABLES IN MACHINE TOOLS, PARTICULARLY PUNCHING MACHINES BACKGROUND OF THE INVENTION This invention relates to the longitudinal carriage drive for coordinates tables in machine tools, particularly punching or stamping machines, for the transporting of the carriages on the coordinates tables, particularly of the longitudinal carriage, with the transverse carriage moving thereupon transversely to the longitudinal axis of the machine, and with the material to be punched or stamped held fast thereon, with power-transmission by screw-threaded spindles. The invention is particularly advantageous with revolving punches, with which the need arises to improve the accuracy of the positioning of the coordinates tables, and to provide the presumptions for the supervision of this accuracy.

SUMMARY OF THE INVENTION The invention consists in the feature that to the left and right of the center of the machine two threaded spindles are arranged, which receive their drive synchronously from a common driving motor arranged on about the center of the table. It has been found particularly advantageous in this case to employ ball rotary spindles, which, in consequence of the initial stress of the ball bearings, ensure running practically free from backlash in the transmission of the driving forces. The adoption of such spindles also has the advantage that the coefficient of friction of the driving spindle is completely invariable.

In a preferred form of construction of the invention, the driving motor and the power-transmitting means between this motor and the threaded spindles are arranged symmetrically about the Y-axis of the longitudinal carriage. Such an arrangement provides particularly advantageous presumptions for the accommodation of monitoring appliances, which already show any change of equilibrium between the drives, or even cut out the drive altogether. As power-transmitting means between the motor and the driving spindles, toothed belt gears are preferred. Such gears provide lightweight steel-armored expansion-free toothed belts, which transmit the driving forces positively and without slipping.

According to a further feature of the invention, with the toothed belts are associated electrical measured-value receivers, for instance electric generators, which, upon disturbance of the state of equilibrium, switch off the drive. It is also possible to associate light cabinets with the toothed belts. It is obvious that with the drive according to the invention, the driving means that are to meet the highest requirements as regards accuracy must remain protected against any disturbance in operation and against overstressing. The arrangement of the monitoring appliances is promoted by the same forces and the same speeds having to occur in each case at the same points in the symmetrically arranged driving system. Any change in the state of equilibrium gives rise to a response from the monitoring appliances, so that disturbances can be directly avoided. It is obvious that by the measures according to the invention, a considerable improvement in the accuracy of working of punching machines is also effected, which can thereby be employed in machining operations which require particularly high accuracy.

One constructional example of the invention is illustrated in the accompanying drawings, as applied to a revolving punch, and will now be further described. The invention is, however, also applicable to punching and stamping machines and other machine tools of a different construction.

In the accompanying drawings,

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a coordinates table in side elevation; FIG. 2 shows a plan view of the coordinates table; and FIG. 3 shows the coordinates table in front elevation.

DETAILED DESCRIPTION OF THE DRAWINGS Upon underpart 1 of the table are arranged, to right and left (FIG. 3), longitudinal girders 2 and 2' for the accommodation and guidance of a longitudinal carriage. To the longitudinal girders 2 and 2' are bolted guiding rails 3 and supporting rails 4, upon which the complete longitudinal carriage is guided and supported, respectively. The longitudinal carriage consists essentially of a cross girder 5, with a left-hand roller shoe 6 and a right-hand roller shoe 6', in which supporting rollers 7 and lateral guiding rollers 8 are journaled. To the underside of the roller shoes 6 and 6' are secured holders 9 and 9' for the accommodation of the ball rotary nuts of ball rotary spindles 10, serving advantageously as a drive, for driving the longitudinal carriage; and upon these roller shoes are secured supporting

plates

11, 11 for the material to be punched. These bearing surfaces thus accompany the movement of the iongitudinal carriage.

The ball rotary spindles 10 are axially mounted in

bearing shields

12 and 12 and

bearings

13 and 13, which are connected fast, in front and behind, with the longitudinal girders 2 and 2' respectively.

Upon the cross girder 5 of the longitudinal carriage is secured a left-hand bearing 14 and a right-hand bearing 15, and also a motor casing 16, with a driving motor for a ball rotary spindle 17 of a transverse carriage 18. A ball rotary nut 19 on the spindle 17 is connected on the other side by its holder with the transverse carriage 18, and to the latter in turn is bolted a clamping rail 20. To this again workpiece-stretchers 21, three in number, for example, are displaceably secured. By these workpiece-stretchers is held material 22 to be punched, consisting of a plate, represented by dot-and-dash lines, for travelling between the upper and lower turntables of rotary punches. The axial positions of the bearings of these turntables are indicated at 23, and that of one of the tool stations at 24.

Between the lateral punching-material supporting plates 1 l and 11', and pivoted to the latter and moved therewith, are located transverse roller'guided punch-material supporting rails 25, which, upon the punched material being removed towards the left (see FIG. 1), are guided over a descending guiding curve 26 into an open space between the underpart l of the table and the transverse girder 5 of the longitudinal carriage and are there caught up. Guiding and connecting chains 27 for the punched-material rails 25 are pivotally connected by their right-hand ends 28 and 28' with the punched-

material supporting plates

11 and 11, and by spring-equipped tension rods 29, in the bearing shields l2, 12', which are secured, under tension, to the front ends of the longitudinal girders 2 and 2'.

The longitudinal carriage drive by the ball rotary spindles 10 is effected completely without slip and with the spindles turning synchronously, by a driving motor 41, which is connected by a bearing shield 40 with the front wall of the underpart 1 of the table, with the aid of toothed belts 42, by way of corresponding toothed disc wheels 43. It will be seen that the power transmitting means between the motor 41 and the spindles are symmetrically arranged about Y-axis of the longitudinal carriage. In connection with the toothed belts 42 are arranged measured-value receivers, for instance electrical generators 44, or, optionally, light sensors 45, which respond to irregular running of the power-transmitting means, or to breakage of a toothed belt, and thereby preclude any injury to the drive, and to the guidance of the longitudinal carriage, by interrupting the drive.

What is claimed is:

l. A longitudinal carriage drive for coordinates tables in machine tools, particularly punching or stamping machines, for impelling the carriages on coordinates tables, particularly a longitudinal carriage, with a transverse carriage moving thereupon transversely to the longitudinal axis of the machine, and to material to be punched held fast thereto, with powerin the state of equilibrium, to deactivate the drive.

2. The longitudinal carriage drive as claimed in claim I, wherein said electrical measurement-value receivers are electric generators.

3. The longitudinal carriage drive as claimed in claim 1, wherein said electrical measurement-value receivers are light sensors.

II I I t t

Claims

1. A longitudinal carriage drive for coordinates tables in machine tools, particularly punching or stamping machines, for impelling the carriages on coordinates tables, particularly a longitudinal carriage, with a transverse carriage moving thereupon transversely to the longitudinal axis of the machine, and to material to be punched held fast thereto, with powertransmission by screw-threaded spindles, the improvement including, to the left and right of the center of the machine, two threaded spindles, a motor arranged at approximately the middle of the table, toothed belt drives between the motor and the threaded spindles for transmitting power to the spindles symmetrically arranged about Y-axis of the longitudinal carriage and electrical measurement-value receivers operably related with the toothed belt drives and, operative upon a disturbance in the state of equilibrium, to deactivate the drive.

2. The longitudinal carriage drive as claimed in claim 1, wherein said electrical measurement-value receivers are electric generators.