GB2413776A

GB2413776A - Nozzle insert for cutting rule bending machine

Info

Publication number: GB2413776A
Application number: GB0410092A
Authority: GB
Inventors: David Michael Starkie; Gregory Fontaine
Original assignee: MP AUTOMATION Ltd
Current assignee: MP AUTOMATION Ltd
Priority date: 2004-05-06
Filing date: 2004-05-06
Publication date: 2005-11-09
Also published as: GB0410092D0

Abstract

A central nozzle portion of a bending machine, which has a slot (48) for guiding cutting rule which is to be bent, is formed as a separate insert (40) which is releasably connected between respective supports (50, 60). This obviates the need to unclamp the supports when the slot size (or nozzle) needs to be changed. The insert (40) advantageously has upper and lower flanges (44, 46) with bevelled and tapering side edges which slidably engage in dovetail grooves in the facing surfaces of the supports (50, 60).

Description

24 1 3776

NOZZLE INSERT FOR CUTTING RULE BENDING MACHINE

The present invention relates to a machine which bends metallic cutting rule to any predetermined configuration required to produce a cutting die, as used, for example, in the production of carton blanks or other shaped pieces of cardboard, paper or plastics material etc. The metallic rule, usually steel, has a cutting blade along one edge and must be handled with care. It is supplied as a coil and fed from a dispenser to the bending machine. Current machines, as described, for example, in US patent specifications US 5787750, US 5870919, US 6128940 and US 6405574 and as illustrated, in part, in Figures 1 and 2 incorporate a bending head 10, also known as a folding device. Bending fingers 14 are selectively axially displaced by actuators 16 to engage through apertures 15 in the head 10 and apertures 17 in associated upper and lower gearing 12, 13. The respective finger 14 is then moved laterally by rotation of the upper and lower gearing 12, 13 under control of a further actuator 18. The actuators 16, 18 are under computer control so as to bend the cutting rule 20 at required positions and to required angles as the cutting rule 20 is fed through the bending head 10. The machine may include other sections where notches are cut into the cutting rule at predetermined locations, and where mitre edges are cut, and the rule is also cut to length.

The bending head 10 of such a machine is a unitary body, as shown in Figure 2, and comprises a narrow central portion, referred to as a nozzle 22, extending between upper and lower annular support portions 24, 26. An elongate, narrow slot 28 is formed through the central portion for passage of the cutting rule 20. The annular support portions 24, 26 are formed with the apertures 15, which are aligned and part-circular in form for projection therethrough of the bending fingers 14.

For effective guiding of the cutting rule 20 the size of the slot 28 must be closely matched to the size of the cutting rule. Therefore, the slot 28 in the nozzle 22 is of a height and width which will accommodate only a specific width (height) and thickness of cutting rule. i 2

The most common widths of cutting rule are 22.30mm, 23.80mm and 30mm. Different bending heads are provided for each width of cutting rule. The central portion or nozzle 22 of the bending head 10 is usually only slightly greater in height than the height of the slot therein, so the bending heads for different widths of cutting rule are often of a different overall height or may have annular support portions of different height.

Different widths of cutting rule are required for different products of the bending machine.

Accordingly, as the machine is switched between successive jobs during the course of a day it is likely that the bending head will on several occasions need to be removed and replaced by another having a different sized feed slot. This is quite a time consuming process and quite dirty too as the machine parts involved are usually covered in oil. First, a top guard has to be removed, then the top gearing 12 has to be disconnected from the upper annular support 24. Bearing housings 30, 32 in which the upper and lower annular supports 24, 26 are clamped, then have to be released to allow removal and replacement of the bending head 10. Once the new head has been substituted and re-clamped, care must be taken that the top gearing 12 is replaced in alignment with the bottom gearing 13 to enable the respective bending finger 14 to engage through both during operation.

An object of the present invention is to simplify the exchange of bending nozzles in a bending machine of this type.

With this object in view the invention provides a bending head for a metallic cutting rule bending machine comprising upper and lower support portions adapted to be clamped in the machine and a central nozzle portion extending between the upper and lower support portions and having a slot therethrough for passage of the cutting rule, characterized in that the central, nozzle portion is a separate element which is releasably inserted between and connected to the respective support portions by slidable interengagement of edge projections and grooves.

The edge projections are preferably provided on the nozzle portion and the grooves on the respective support portions, but this could be the other way around.

A particularly reliable interengagement, which is both secure, yet readily releasable, and which also allows the nozzle portion to be smoothly guided into and out of position in the bending head is afforded by having the edge projections and grooves of interlocking dovetail configuration.

In preferred embodiments the nozzle portion is tapered in its direction of insertion between the support portions. This shape is advantageous in resisting inadvertent dislodgement of the engaged nozzle portion under considerable lateral bending forces exerted by the bending fingers. With this shape any lateral impact will tend to locate the nozzle portion more securely.

Furthermore, in preferred embodiments the nozzle portion is provided with upper and lower flanges, and it is these flanges which are provided with the edge projections or grooves for interengagement with the support portions.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view showing part of a prior art bending machine with cutting rule being fed through, as already described; Fig. 2 is an enlarged exploded view of the bending head and gears connected thereto from

the prior art machine illustrated in Fig. 1;

Fig 3 is a front view of a preferred embodiment of a bending head in accordance with the present invention; Fig. 4 is a plan view of the bending head shown in Fig. 3; Figs. 5, 6 and 7 are respectively a front view, side view and plan view, to slightly enlarged scale, of the nozzle portion (also referred to as the nozzle insert) of the bending head shown in Figs. 3 and 4; and Figs. 8 and 9 are front views, also to a slightly enlarged scale, of the upper and lower support portions of the bending head shown in Figs. 3 and 4.

A preferred embodiment of a bending head of the present invention comprises three separate components, namely a nozzle insert 40, as shown in Figs. 5 to 7, an upper support lO element 50, as shown in Fig. 8 and a lower support element 60 as shown in Fig. 9. In use these are fitted together as shown in Figs. 3 and 4, but the upper and lower support elements 50, 60 are substantially permanently clamped into upper and lower bearing housings (as 30, 32 in the prior art Fig. 1) of a bending machine while the nozzle insert 40 is releasably fitted therebetween. Thus, in contrast to the prior art unitary bending head 10 there is no need to unclamp the support elements 50, 60 to exchange the nozzle for one adapted for guiding a different width of cutting rule.

The nozzle insert 40, as shown in Figs. 5 to 7, is a one piece steel casting comprising a narrow central body 42 extending between upper and lower flanges 44, 46. The central body 42 has a narrow slot 48 therein defining a passage for a specific width of cutting rule (not shown). The passage extends from a rear inlet 41 to a front outlet 43, where the body 42 is chamfered. The flanges 44, 46 are substantially symmetrical and extend laterally of the central body 42 at both sides. The flanges 44, 46 have side edges 54 which are bevelled on facing surfaces and also taper slightly towards the rear of the central body 42, as is apparent by reference to Figs. 5 and 7. Thus, in front view (Fig. 5), the respective flanges 44, 46 have a symmetrical dovetail configuration.

The flanges 44, 46 also extend beyond the front of the central body 42 to an arcuate front edge 49. Immediately in front of the slot outlet 43, the flanges 44, 46 are provided with part circular openings 47, through which bending fingers (as 14 in the prior art Fig. 1) extend during use of the bending head. s

The upper support element 50 is a robust, substantially annular body having a pair of slightly tapering undercut dovetail grooves 52 formed in its lower surface, as shown in Fig. 8.

The lower support element 60 is a similar substantially annular body of lesser height than the upper element 50, but formed with a corresponding pair of slightly tapering undercut dovetail grooves 62 formed in its upper surface, as shown in Fig. 9.

In use, the nozzle insert 40 is fitted between the upper and lower supports 50, 60 to provide a complete bending head, as shown in Figs. 3 and 4. The edges of the flanges 44, 46 are a snug, sliding, interlocking fit into the dovetail groove pairs 52, 62. The insert 40 is introduced from the front and pushed in towards the rear, i.e. in the direction of the taper in the sides of the flanges 44, 46. The upper and lower elements 50, 60 are then clamped into the bearing housings of the bending machine.

When a different width of cutting rule is to be dealt with in the bending machine, the nozzle insert 40 is removed and replaced with another similar insert of identical external dimensions but which has a slot 48 of an appropriate height to match the new cutting rule.

This is accomplished without unclamping the supports 50, 60 from the machine and is achieved quite simply by tapping the insert 40, e.g. with a hammer or similar tool, from the rear to release it slightly from its engagement in situ with the supports 50, 60. It can then be slid forwards until completely released. The new insert is then inserted in the opposite way by sliding it in from the front and tapping it home.

The taper configuration of the grooves 52, 62 and the side edges of the flanges 44, 46 is effective in ensuring that the insert 40 is securely retained notwithstanding the high bending forces during operation of the bending machine.

Compared to the prior art, where the support portions are integral with the nozzle portion, the support elements of the inventive assembly can be of a simpler configuration as the part circular openings necessary for the bending figures can be entirely provided within the flanges of the nozzle insert.

The foregoing description is not limitative of the scope of the invention. Many variations in design detail are possible in other embodiments of the invention as will be apparent to those skilled in the art.

Claims

1. A bending head for a metallic cutting rule bending machine comprising upper and lower support portions adapted to be clamped in the machine and a central nozzle portion extending between the upper and lower support portions and having a slot therethrough for passage of the cutting rule, characterized in that the central nozzle portion is a separate nozzle insert element which is releasably inserted between and connected to the respective support portions by slidable interengagement of edge projections and grooves.

2. A bending head as claimed in claim 1 wherein the edge projections are provided on the nozzle portion and the grooves are provided on the respective support portions.

3. A bending head as claimed in claim 1 or 2 wherein the edge projections and grooves are of interlocking dovetail configuration.

4. A bending head as claimed in claim 1, 2 or 3 wherein the nozzle portion is tapered in its direction of insertion between the support portions.

5. A bending head as claimed in any preceding claim wherein the nozzle portion comprises upper and lower flanges whereby the releasable interconnection with the respective support portions is accomplished.

6. A bending head as claimed in claim 5 wherein the respective flanges have aligned part-circular openings therethrough adjacent an outlet of the slot.

7. A nozzle insert for use in a bending head as claimed in any preceding claim.

8. A bending head substantially as hereinbefore described with reference to and as illustrated in Figs. 3 to 9 of the accompanying drawings.

9. A nozzle insert substantially as hereinbefore described with reference to and as illustrated in Figs. 5 to 7 of the accompanying drawings.