GB2038680A

GB2038680A - Kinematic drive, in particular for driving loading and unloading apparatus of machine tools such as presses, punches and the like

Info

Publication number: GB2038680A
Application number: GB7937903A
Authority: GB
Original assignee: Maschinenfabrik Weingarten AG
Current assignee: Maschinenfabrik Weingarten AG
Priority date: 1978-11-02
Filing date: 1979-11-01
Publication date: 1980-07-30
Also published as: DE2847543C3; IT7926999A0; IT1209397B; FR2440233A1; GB2038680B; JPS55106641A; DE2847543A1; DE2847543B2

Abstract

A workpiece transfer mechanism for a machine tool comprises a conveyor arm 14 forming one side of a first parallelogram linkage 7, 10, 11, 14 with four floating pivot axes. A second parallelogram linkage 1, 8, 10, 12 has two fixed pivot axes 2, 24 and two floating pivot axes coinciding with two of the pivot axes of the first parallelogram linkage. A drive shaft comprises one of said fixed pivot axes 2 and is fixedly connected by a drive arm 8 to one of said two floating pivot axes 9. A cam 1 is rotationally fast with said drive shaft. A carriage 5 is arranged to reciprocate under the influence of said cam and carries a pivotal guide 6 slidably receiving an extension 7a of the arm 7 forming the third side of said first parallelogram linkage. In use the cam 1 modifies the path of movement of the conveyor arm 14 dictated by the carriage 5 acting through the first parallelogram linkage. <IMAGE>

Description

SPECIFICATION Kinematic drive, in particular for driving loading and unloading apparatus of machine tools such as presses, punches and the like The invention relates to a kinematic drive in particularfor driving loading and unloading apparatus of machine tools such as presses, punches and the like with a conveyor arm, which carries out a reciprocating, substantially rectilinear horizontal first partial movement, which is followed by vertical movements, possibly shifted through 90 , the conveyor arm being pivotally connected to a parallelogram linkage, which in turn comprises two levers mounted in parallel at fixed pivot points, one of which is constructed in the manner of a crank arm as a drive shaft and serves to control a cam in order to achieve a predetermined sequence of movements.

The most varied loading and unloading apparatus have been proposed for inserting and removing workpieces in presses. In order to ensuretroublefree removal of the work-pieces, which frequently have a relatively large overall height, from the working space of the press, it is thus frequently necessary for the corresponding conveyor arms firstly to make a vertical movement and then a longer horizontal movement. These movements are generally then followed by a further vertical downwards movement for depositing the work-piece. When supplying the press, these movements take place in reverse sequence.

One construction which approaches this requirement is known from German Auslegesschrift 2439 722. However, the latter has the drawback that the sequences of movements are kept within relatively narrow limits, a relatively complicated control device comprising a switching circuit is provided for the corresponding control roller and any change in the sequence of movements provided originally necessitates considerably complicated and therefore expensive structural alterations.

This is where the present invention is put into action and the object of the latter is to carry out the respectively desired movements of the conveyor arm, which are shifted through 900 with respect to each other, including the course of the transition curve between the horizontal and vertical movement by even simpler means.

For this purpose, in a kinematic drive of the afore-described construction, it is proposed according to the invention that the cam is seated on the drive shaft and co-operates with guide rollers of a sliding member, which at its upper end supports a guide which is mounted in a rotary manner, through which the extension of a parallelogram lever passes and is guided to slide in the latter.

It is thus an advantage that the cam has a construction corresponding to the respectively desired movement of the conveyor arm and can be exchanged.

In comparison with the prior art, the construction of the kinematic drive according to the invention is simpler and it can be adapted quickly and without great expenditure to any sequence of movements, by simply exchanging the cam disc.

The invention will be described in deitail-hereafter with reference to the drawings which show one embodiment partly diagrammatically: Figure 1 shows the position during introduction of the work-piece into the press, Figure 2 shows the position after horizontal removal from the pressand Figure 3 shows the position-after lowering the workpiece onto the corresponding support.

The kinematic drive according to the invention is illustrated in the drawings in conjunction with apress which is shown diagrammatically. It consists essentially of a parallelogramlinkage, which consists of the two parallelogram levers 7 and 11, an upper connecting plate 10, the conveyor arm 14 as well as of two levers 8 12, which are mounted at fixed pivot points 24 and 2 of the housing 22. The pivot point 2 is thus constructed as a drive shaft and the lever 8 acts in the manner of a crank arm. The parallelogram lever 7 is constructed with an extension 7a at its upper end, which extension passes through a guide 6 and is thus guided between rollers 25, 26, 27 and 28. The guide 6 is thus mounted to rotate at a point 28 at the upper end 5a of a carriage 5 constructed as a slide.This carriage 5 is mounted to move in the housing 22 in the directions indicated by the arrow 30 and comprises guide rollers 3 and 4, which co-operate with the actual cam 1.

The path of movement of the fulcrum 7b for example, illustrated in dot-dash lines by the reference numeral 23 in the figures, is determined by the shape of the cam 1. The parts of the press, namely the press support, the lower tool and the upper tool are designated by the reference numerals 19, 18 and 20 respectively. The reference numeral 13 designates mounting supports for the conveyor arm 14, the reference numeral 15 a mounting support constructed with suction arms, the reference numeral 16 the actual workpiece and the reference numeral 17 the station at which the workpiece 16 is deposited.

A suitable cross bar 21 on the press stand 19 for example is provided for the suspension of the kinematic drive according to the invention. As can be seen from the drawings, the workpiece 16 picked-up by the suction member 15 in Figure 1 is raised and then moved horizontally out of the press into the position illustrated in Figure 2 and then guided vertically downwards to the station 17 for depositing the workpiece, as illustrates in Figure 3.

1. A workpiece transfer mechanism for a machine tool, comprising a transfer arm forming one side of a first parallelogram linkage with four floating pivot axes, a second parallelogram linkage having two fixed pivot axes and two floating pivot axes coinciding with the two pivot axes at the opposite side of the first parallelogram linkage, a drive shaft providing one of said fixed pivot axes and fixedly connected by a drive arm to one of said two floating pivot axes, a cam rotationally fast with said drive shaft, and a slide arm arranged to reciprocate under the influence of said cam and carrying a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Kinematic drive, in particular for driving loading and unloading apparatus of machine tools such as presses, punches and the like The invention relates to a kinematic drive in particularfor driving loading and unloading apparatus of machine tools such as presses, punches and the like with a conveyor arm, which carries out a reciprocating, substantially rectilinear horizontal first partial movement, which is followed by vertical movements, possibly shifted through 90 , the conveyor arm being pivotally connected to a parallelogram linkage, which in turn comprises two levers mounted in parallel at fixed pivot points, one of which is constructed in the manner of a crank arm as a drive shaft and serves to control a cam in order to achieve a predetermined sequence of movements. The most varied loading and unloading apparatus have been proposed for inserting and removing workpieces in presses. In order to ensuretroublefree removal of the work-pieces, which frequently have a relatively large overall height, from the working space of the press, it is thus frequently necessary for the corresponding conveyor arms firstly to make a vertical movement and then a longer horizontal movement. These movements are generally then followed by a further vertical downwards movement for depositing the work-piece. When supplying the press, these movements take place in reverse sequence. One construction which approaches this requirement is known from German Auslegesschrift 2439 722. However, the latter has the drawback that the sequences of movements are kept within relatively narrow limits, a relatively complicated control device comprising a switching circuit is provided for the corresponding control roller and any change in the sequence of movements provided originally necessitates considerably complicated and therefore expensive structural alterations. This is where the present invention is put into action and the object of the latter is to carry out the respectively desired movements of the conveyor arm, which are shifted through 900 with respect to each other, including the course of the transition curve between the horizontal and vertical movement by even simpler means. For this purpose, in a kinematic drive of the afore-described construction, it is proposed according to the invention that the cam is seated on the drive shaft and co-operates with guide rollers of a sliding member, which at its upper end supports a guide which is mounted in a rotary manner, through which the extension of a parallelogram lever passes and is guided to slide in the latter. It is thus an advantage that the cam has a construction corresponding to the respectively desired movement of the conveyor arm and can be exchanged. In comparison with the prior art, the construction of the kinematic drive according to the invention is simpler and it can be adapted quickly and without great expenditure to any sequence of movements, by simply exchanging the cam disc. The invention will be described in deitail-hereafter with reference to the drawings which show one embodiment partly diagrammatically: Figure 1 shows the position during introduction of the work-piece into the press, Figure 2 shows the position after horizontal removal from the pressand Figure 3 shows the position-after lowering the workpiece onto the corresponding support. The kinematic drive according to the invention is illustrated in the drawings in conjunction with apress which is shown diagrammatically. It consists essentially of a parallelogramlinkage, which consists of the two parallelogram levers 7 and 11, an upper connecting plate 10, the conveyor arm 14 as well as of two levers 8 12, which are mounted at fixed pivot points 24 and 2 of the housing 22. The pivot point 2 is thus constructed as a drive shaft and the lever 8 acts in the manner of a crank arm. The parallelogram lever 7 is constructed with an extension 7a at its upper end, which extension passes through a guide 6 and is thus guided between rollers 25, 26, 27 and 28. The guide 6 is thus mounted to rotate at a point 28 at the upper end 5a of a carriage 5 constructed as a slide.This carriage 5 is mounted to move in the housing 22 in the directions indicated by the arrow 30 and comprises guide rollers 3 and 4, which co-operate with the actual cam 1. The path of movement of the fulcrum 7b for example, illustrated in dot-dash lines by the reference numeral 23 in the figures, is determined by the shape of the cam 1. The parts of the press, namely the press support, the lower tool and the upper tool are designated by the reference numerals 19, 18 and 20 respectively. The reference numeral 13 designates mounting supports for the conveyor arm 14, the reference numeral 15 a mounting support constructed with suction arms, the reference numeral 16 the actual workpiece and the reference numeral 17 the station at which the workpiece 16 is deposited. A suitable cross bar 21 on the press stand 19 for example is provided for the suspension of the kinematic drive according to the invention. As can be seen from the drawings, the workpiece 16 picked-up by the suction member 15 in Figure 1 is raised and then moved horizontally out of the press into the position illustrated in Figure 2 and then guided vertically downwards to the station 17 for depositing the workpiece, as illustrates in Figure 3. CLAIMS

1. A workpiece transfer mechanism for a machine tool, comprising a transfer arm forming one side of a first parallelogram linkage with four floating pivot axes, a second parallelogram linkage having two fixed pivot axes and two floating pivot axes coinciding with the two pivot axes at the opposite side of the first parallelogram linkage, a drive shaft providing one of said fixed pivot axes and fixedly connected by a drive arm to one of said two floating pivot axes, a cam rotationally fast with said drive shaft, and a slide arm arranged to reciprocate under the influence of said cam and carrying a pivotal bearing slidably receiving an extension of an arm forming a third side of said first parallelogram linkage, whereby, in use, the cam modifies the path of movement of the transfer arm dictated by the drive arm acting through the first parallelogram linkage.

2. A mechanism as claimed in claim 1, wherein the cam is a profiled disc cooperating with follower rollers mounted on the slide arm.

3. A mechanism as claimed in claim 1 or 2, wherein the cam is exchangeably mounted on the drive shaft.

4. A workpiece transfer mechanism for a machine tool, substantially as herein described with reference to and as illustrated in the accompanying drawings.