GB2086716A

GB2086716A - Process and apparatus for producing slender brushes

Info

Publication number: GB2086716A
Application number: GB8131903A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-10-22
Filing date: 1981-10-22
Publication date: 1982-05-19
Also published as: DE3039798A1; GB2086716B; DE3039798C2

Abstract

The toothbrush (3) is held on a workpiece holder (4) by chuck jaws (5) on a chuck drum (16). For removal to a finishing station after the appropriate machining the drum (16) is rotated to move the brush (3) to its lowest position where a gripper (generally designated 2) may engage it after it has been released to fall onto a movable stopper (22). The upper gripper jaw (7) may also assist removal of the brush (3) from the chuck. The gripper arm (6) is rotated to remove the brush (3) sideways from the chuck (16) when the brush (3) has fallen clear of the immediate region of the workpiece jaws (4, 5). The removal may additionally or alternatively be axially parallel to drum (16). The gripper (generally designated 2) may be formed from an arm (6) with a fixed jaw (8) and a pivoted arm (18) with its respective jaw (7) and operated by a retaining spring (19) and piston and cylinder assembly (20). <IMAGE>

Description

SPECIFICATION Process and apparatus for producing slender brushes The invention relates to a process for producing slender brushes, possibly having a stem or handle, more particularly toothbrushes, in which the brushes are conveyed from a workpiece holder, preferably performing hole-tohole movements, to another machine unit or the like.The invention further relates to a brush-making machine with a transfer device for conveying elongate brushes, possibly having a stem or handle, more particularly toothbrushes, from a workpiece holder to another machine unit or the like, wherein the brushes are held, in the region of their bristle area, by chuck jaws of the workpiece holder, at least during machining, and the transfer device has at least one gripper, which executes a partial conveying movement and is provided with clamping jaws or the like, for temporarily holding or conveying the brush, more particularly for performing the process described hereinbefore.

A method of producing toothbrushes is already known wherein prepared toothbrush bodies are provided with bristles in a brush drilling and filling machine and then, in another processing machine, the bristles are trimmed, for example, and/or shaped; an auxiliary apparatus is used to effect the transfer from the brush drilling and/or filling machine, for example, to an automatic finishing machine to which the individual brush bodies are fed in the correct position (cf. for example DE-OS 24 51 752 and DE-OS 25 56 710).

These known processes and apparatus have a number of disadvantages. For example, they operate using feed hoppers or collecting containers and guide tubes arranged behind these or other transport means. These then generally have to be followed by special apparatus for correcting the position of the brush bodies.

Apparatus of this kind are advantageous for many purposes but more frequently they are very complex in construction and take up a great deal of space. The process is also correspondingly complex.

A transfer device for conveying brush bodies from a brush-making machine to a processing machine is also already known, wherein the brushes are initially gripped in the region of their bristle area by chuck jaws of the workpiece holder of the first brush-making machine. When the brush body is transferred, the transfer device engages in the region of the workpiece holder of the first processing machine before the workpiece holder releases the brush body (cf. DE-GM 80 1 3 025). This process and the associated apparatus have numerous major disadvantages; for example, in the case of flat, slender brush bodies such as, for example, toothbrush bodies, there is very little room in the region of the bristle area, where both the chuck jaws of the workpiece holder and also the grippers of the known transfer device act on the brush body simultaneously at times.A particular disadvantage is that the transfer device must already be engaging on the brush body whilst the latter is still executing hole-to-hole movements, e.g. for the filling operation. Accordingly, the gripper means of the transfer device must be able to follow the movement of the brush body or its workpiece holder in the hole-to-hole movement in at least two directions. The removal of the brush body from the known, drum-shaped brush body carrier is achieved first by a radial movement of the chuck jaws of the transfer device relative to the drum-shaped brush body carrier of the known apparatus; this is followed by a pivoting movement of these gripper jaws. Thus, in addition to the movements of the gripper jaws mentioned above (gripper movement and motion with the hole-to-hole movement) there are also the radial and pivotal movements mentioned above.The progress of a process of this kind and the mechanical complexity of the apparatus are therefore expensive and prone to breakdown. A further disadvantage is that adaptation of the transfer device to brush bodies of other shapes requires correspondingly extensive arrangement and adjustment.

The aim is therefore to provide a process for producing slender brushes, particularly toothbrushes, wherein, whilst avoiding the disadvantages of known brush-making processes, on the one hand a brush body is easily transferred from a workpiece holder to another machine unit and on the other hand this transfer occurs within a course of movement which is aimost entirely controlled.

The solution according to the invention consists, in particular, in the fact that, in a process of the type described hereinbefore, the brush is released from the workpiece holder and moved out of the chuck range thereof and is then gripped for conveying, and is conveyed onwards tangentially and/or axially parallel to the direction of movement of the workpiece holder, at least in a first section.

Owing to the fact that, during the transfer, the brush is first released from the chuck jaws of the first brush-making machine, e.g. the brush filling machine, and only afterwards, albeit immediately afterwards, is the brush body gripped for the transfer, a number of advantages are obtained. The workpiece holders of the first brush-making machine do not act on the brush body at the same time as the transfer device, which would lead to a complicated course of movement, particularly if, as it often the case, the brush body was executing a hole-to-hole movement in the first brushmaking machine.At the same time, after leaving the first brush making machine, the brush body is prevented, for example, from falling freely into a hopper and from there being subjected only to lateral guiding, e.g. in a tube; this makes it necessary to adopt additional measures for the further processing of the brush body, as mentioned hereinbefore.

Moreover, in the process according to the invention, the transfer operation for one type of brush, particularly toothbrushes, can in practice be used for a plurality of similar but different designs; only slight adaptation may be necessary.

In a brush-making machine of type described hereinbefore, the machine for carrying out the process is characterised particularly in that the points of engagement of the grippers of the transfer device on the brush are located outside the range of the chuck jaws, after the brush has been released from the jaws of the workpiece holder, and at least during part of the transfer the removal device extends axially parallel and/or at a tangent to the axis of the gripping points. A brush-making machine of this kind or the transfer device thereof has the advantages mentioned hereinbefore in connection with the process. Furthermore, the transfer device can easily be mounted below a workpiece holder constructed in the form of a drum.A filling tool offset by 90 thereto, counter to the movement of the drum, is easily accessible both for observation and also for maintenance, e.g. in the case of breakdowns. The brush bodies provided, for example, with bristles in this brush-making machine can fall a short distance into the transfer device after the end of this operation. The hole-to-hole movement of the workpiece holder does not disrupt the transfer operation and this movement does not have to be stopped for the transfer. In particular, toothbrushes generally have stems or handles of identical or virtually the same thickness, which means that as a rule the transfer device does not have to be adapted to different toothbrush designs or need only be adjusted slightly.Since the courses of movement of the first brush-making machine, on the one hand, and the transfer device, on the other hand, are independent of each other, the transfer device in particular can be simple and robust in construction. Some additional developments of the invention are described in features of further sub-claims and in the description. The invention is hereinafter explained more fully, with its essential details, with reference to embodiments by way of example.

In the drawings, some of which are highly diagrammatical and to various scales: Figure 1 is a side view of a transfer device mounted in a brush-making machine constructed as a drum-type machine.

Figure 2 is a side view of the embodiment shown in Fig. 1, in the direction of the arrow A in Fig. 1, Figure 3 is a detailed view, on a larger scale, in the region of the clamping jaws of the transfer device with the brush clamped therein, Figure 4 is a view from below of the arrangement shown in Fig. 1, and Figure 5 is a partial perspective view of clamping jaws with a section of brush stem located between them.

In a brush-making machine 1, in this case in the form of a drum-type machine, there is a transfer device 2. It is used for conveying toothbrushes 3, in particular, from a workpiece holder 4 in the brush-making machine 1 to another machine unit not shown here, e.g.

a conveyor belt, a finishing machine or the like. During the processing in the brush-making machine 1, the brushes 3 are held in the region of their bristle area by the chuck jaws 5 of the workpiece holder 4.

In the embodiment by way of Example (Figs. 1 and 4), the transfer device 2 has several, in this case four gripper arms 6 in the outer ends of which there are arranged two gripper jaws 7 and 8 movable towards each other for gripping the stem or handle 9 of a brush body. The gripper jaws 7,8 preferably engage substantially in the central region of the brush stem 9, particularly on the flat sides 9a thereof.

The transfer device 2 is in the operational position when the workpiece holder 4 of the brush making machine 1 is in a lowered position, preferably in the bottom position.

Below this workpiece holder 4 there is a space for release of the brush body.

To transfer a brush 3 from the brushmaking machine 1 to the transfer device 2, the brush is first released from the workpiece holder 4 and moved out of the chuck range thereof and then gripped by the gripper jaws 7,8 and moved out of the region of the brushmaking machine. Thanks to the arrangement of the transfer device 2 with the workpiece holder 4 in the lowest position, the release of the toothbrush 3 or the like from the workpiece holder 4 can be achieved under the effect of gravity or at least gravity-aided, whilst preferably an ejector device is additionally provided, having an ejector for the brush bodies 3, which is, in particular, biased with a resetting force. In the embodiment by way of example, the ejector is formed by one of the gripper jaws 7. The ejector device ensures that the brushes 3 reliably fall out when the chuck jaws 5 of the workpiece holder 4 open, particularly as it often happens that the brushes remain on the workpiece holder even when the chuck jaws are opened.

Figs. 1 and 3 cleariy show that the gripper jaws 7,8 are arranged with their gripping surfaces 1 0 (cm. Fig. 5) substantially horizontally, the lower gripper jaw 8 being fixedly mounted with respect to the gripping movement and being arranged at a spacing from the stem 9 of the brush body clamped therein, whilst the upper gripper jaw 7 is movably mounted for the gripping movement.

When the chuck jaws 5 of the workpiece holder 4 have released the brush 3, this brush is able to drop down slightly, and come to rest with its stem 9 on the lower gripper jaw 8. In order to grip the brush stem 9 securely, and more particularly to prevent this stem from slipping sideways over the gripper jaw 8, this lower gripper jaw 8 has a receiving channel 1 2 formed by a substantially U-shaped cross-section (Fig. 5). If the brush 3 is left hanging in the workpiece holder 4 even after the chuck jaws 5 have opened, it is forced out of the workpiece holder 4 when the upper gripper jaw 7 is lowered in the direction of the arrow Pf 1.Minor relative movements of the brush 3 at this moment, e.g. caused by positioning movements of the brush-making machine, do not have any disrupting effect, since, as the gripper jaw 7 moves into engagement, the brush is indeed acted upon by this jaw 7 but is not yet firmly clamped between this and the gripper jaw 8. A balance is achieved, in particular, by the free movement between the clamping in the workpiece holder 4 on the one hand, and the clamping between the gripper jaws 7 and 8, on the other hand. To improve the insertion of the brush stem 9 in the receiving channel 1 2 of the gripper jaw 8, this channel preferably has lateral run-in slopes 1 3 to make it into a funnel shape.Fig. 3, in particular, shows that the spacing a of the contact side 14 of the lower gripper jaw 8 from the underside 1 5 of the brush body which is to be acted upon is greater than the height h of the chuck jaws 5 of the workpiece holder 4. The spacing a also simultaneously constitutes the drop height within which neither the chuck jaws 5 nor the gripper jaws 7, 8 are in clamping engagement. The above-mentioned dimensional arrangements ensure that the brush 3 moves out of the range of engagement of the chuck jaws 5, so that it can subsequently be removed laterally therefrom without any obstruction. The first conveying movement by the transfer device 2 occurs substantially at a tangent to the direction of travel of the workpiece holder 4 and then merges into a movement parallel to the rotation axis of the drum 16.In addition to performing the pivotal movement shown in the embodiments by way of example, the transfer device 2 may also be constructed so that the removal of the brushes from the workpiece holder 4 occurs as an axially parallel, e.g. a linear movement. Besides the tangential or axially parallel movement of removal, another movement of removal may also be superimposed, e.g. axially parallel at first and then, in particular, tangential, by means of a pivotal movement. The essential point is that there are no significant guided radial movements relative to the rotation axis of the drum 16. Rather, the brushes 3 are conveyed out of the area of operation of the brush-making machine 1 virtually by the shortest route, without any need for the gripper jaws 7, 8 to go along with a movement prescribed by the workpiece holder 4.

Fig. 1 and the corresponding view of the underside shown in Fig. 4 show that the four gripper arms 6 provided in the embodiment by way of example are mounted so as to be rotatable about a rotation axis 1 7 arranged at right angles to the axis T of the drum. The brushes 3 taken from the brush-making machine 1 or the workpiece holder 4 thereof by the transfer device 2 are pivoted out of the region of the drum in the direction of the arrow Pf 2 and are brought, for example, into a position offset by 90 thereto. A further processing machine (not shown here) may be provided at this point.

The upper gripper jaws 7 (Fig. 1) are movably mounted on levers 18 which are in turn rotatably mounted and held in the open position by a spring 1 9. For the gripping movement in the direction of the arrow Pf 1 a lifting cylinder 20 is provided which pivots the lever 18. In the case of gripper jaws 7, 8 which do not execute a movement parallel to each other during the gripping movement, as is the case in Fig. 1, it may be appropriate for at least the gripper jaw 7 with its gripping surface 10 to be somewhat flexible in construction, so as to balance out this inclined position when the lever 18 is pivoted relative to the contact surface of the gripper jaw 8.

The gripping surfaces of the gripper jaws 7, 8 may also have a coating, e.g. a plastics coating, to avoid damage to the brush bodies held thereon.

In order to prevent any toothbrushes 3 which have fallen out of the workpiece holder 4 before the gripper jaws 7, 8 have closed from moving into an inclined position, a receiving support 22, preferably adjustable in height but otherwise fixed, for the end of the brush body with the bristle area, may be provided on an extension of the lower gripper jaw 8, which is in the operational position, below the workpiece holder 4 which is in the ejecting position. Appropriately, the contact surface 24 of this receiving support 22 is arranged lower down than the contact surface 14 of the lower gripper jaw 8, by a distance corresponding substantially to the length of the tufts of bristles in the brush 3.After the brush 3 has been released by the workpiece holder 4, this brush, possibly with the aid of the upper jaw 7 as an ejector element, falls into a substantially horizontal position, in which it is supported on the one hand by the gripper jaw 8 and on the other hand by the receiving support 22. In particularly, this will prevent the brush from being displaced longitudinally as a result of the inclined position which would otherwise occur. For the transfer device shown in the Figures the receiving sup port 22 has only a flat contact surface 24, which means that the brush can be moved sideways out of the region of the workpiece holder 4.In the case of a linear direction of removal in which the brush bodies are removed substantially parallel to the rotation axis T of the drum-type machine, the receiving support 22 could also have lateral run-in surfaces and thus be substantially channelshaped so as to support the brush body at the sides as well.

The transfer device according to the invention is particularly simple in construction and therefore not prone to breakdown. Moreover, thanks to the movement of removal and transportation substantially parallel to the drum axis or other rotation axis, or tangential to the direction of travel of the workpiece holder, and possibly at least partly overlapping, there is the major advantage that the brushes 3 are moved out of the region of the brush-making machine, particularly the drum or drums 1 6 thereof or the like, by a short route which is favourable for the later processing machines.

Figs. 1 and 2 also clearly show 2 magazine 26 from which brush bodies are fed to the chuck drum 1 6 for further processing.

All the features appearing in the description, claims and drawings may be essential to the invention both individually and in any desired combinations with one another.

Claims

1. A process for producing slender brushes in which the brushes are conveyed from a workpiece holder to another working station including releasing the brush first from the workpiece holder moving it out of the chuck range thereof and then gripping it for conveying onwards tangentially and/or axially parallel to the direction of movement of the workpiece holder.

2. A process as claimed in claim 1 including gripping the brush outside its bristle attachment area for conveying purposes.

3. A process as claimed in claim 1 or 2, including moving the brush out of the range of the workpiece holder into the region of the transfer movement with the aid of gravity.

4. Brush-making apparatus having a transfer device for conveying elongate brushes from a workpiece holder to another working station or the like, said workpiece holder having chuck jaws adapted to hold a said workpiece in the region of its bristle area at least during machining, the transfer device having at least one gripper for temporarily holding or conveying the brush, executing at least a partial conveying movement and being provided with clamping jaws or the like, the point of engagement of the gripper of the transfer device on the brush, after it has been released from said chuck jaws, being located away from the chuck jaws and the direction of removal of a brush, at least during part of the transfer, extending axially parallel and/or at a tangent to the direction of movement of the chuck jaws at the time of release.

5. Apparatus as claimed in claim 4, in which with the workpiece holder in the transfer position, there is provided on the transfer device an ejector device having an ejector for the brush body.

6. Apparatus as claimed in claim 5 wherein the ejector device is formed by at least one of the gripper jaws.

7. Apparatus as claimed in claim 5 wherein the ejector device forms part of the gripper arm.

8. Apparatus as claimed in any of claims 4 to 7, in which the operating position of the transfer device corresponds to a lowered position of the workpiece holder of a drum-type machine and a space for the release of a brush body is provided below this workpiece holder.

9. Apparatus as claimed in any of claims 4 to 8, in which the transfer device has at least one gripper arm with two gripper jaws movable towards each other, for gripping the stem of a brush body or the like.

10. Apparatus as claimed in claim 9, in which the gripper jaws are arranged with their gripping surfaces substantially horizontal, the lower gripper jaw being fixedly mounted in the direction of gripping movement and at a spacing from the brush body when clamped in position, whilst the upper gripper jaw is movably mounted for the gripping movenent.

11. Apparatus as claimed in claim 9 or 10 in which one of the gripper jaws has a receiving channel formed by a substantially Ushaped cross-section of this jaw for receiving the stem of a brush body or the like.

1 2. Apparatus as claimed in claim 9, 10 or 11 in which the spacing of the contact side of the lower gripper jaw from the underside of the brush body which is to be acted upon, when the brush body is in the clamped position in the workpiece holder, is greater than the height of the chuck jaws of the workpiece holder.

1 3. Apparatus as claimed in any of claims 9 to 1 2, in which one of the gripper jaws is spring biased to the open position and actuated by piston cylinder assembly.

14. Apparatus as claimed in any of claims " 9 to 1 3 in which the gripper arm with the gripper jaws executes a movement of removal which is at least substantially linear and directed at right angles to the direction of travel of the workpiece holder.

1 5. Apparatus as claimed in any of claims 4 to 14, wherein the workpiece holders are arranged on a drum, rotatable about an axis, and a plurality of gripper arms are mounted so as to be rotatable about an axis arranged at right angles to the drum axis.

16. Apparatus as claimed in any of claims 4 to 15, in which below the workpiece holder in its ejecting position, there is mounted a receiving support or the like for the bristle end of the brush body located there.

1 7. Apparatus as claimed in claims 9 and 16, in which the contsact surface of the receiving support or the like is mounted lower than the contact surface of the lower gripper jaw, by a distance corresponding substantially to the length of the tufts of bristles of the brush.

1 8. Apparatus as claimed in any of claims 4 to 17, in which the transfer device has at least two pivotable gripper arms with grippers and that the gripper arms have a common pivot axis, are rigidly connected to each other in the longitudinal direction and each execute a pivoting movement preferably of about 90 .

1 9. Apparatus as claimed in any of claims 4 to 18, in which the transfer device has four gripper arms mounted on a common pivot axis and offset by 90 relative to each other.

20. Apparatus as claimed in any of claims 9 to 1 9 for machining brushes with a flat stem or handle, in that the gripper jaws engage on the flat sides of the stem of the body.

21. Apparatus for making brushes, substantially as herein before described with reference to the accompanying drawings.

22. A process for producing brushes substantially as hereinbefore described with reference to the accompanying drawings.