Method and machine for producing brushes

Abstract

 For producing brushes comprising tuft patterns composed of tufts differing in at least one of shape, color, filament type, filament thickness and filament finishing, a set of tufts is composed for each brush to be produced by inserting tufts into holes of a carrier arranged in a pattern corresponding to the desired tuft pattern. The carriers are moved through a number of successive tufting stations. A single tuft is filled into a particular one of the carrier holes in each of the tufting stations. The tuft pattern in each carrier is thus successively composed by moving the carrier through the number of tufting stations. The set of tufts is ultimately joined with a brush body by one out of several possible methods.

Description

[0001] The present invention relates to a method and machine for producing brushes and, in particular, toothbrushes.

[0002] Basic methods of producing toothbrushes having a tuft pattern with a variety of tuft configurations are disclosed in EP 0 972 464 B1 and EP 0 972 465 B1. The methods disclosed therein use a carrier plate with parallel holes arranged in a pattern that corresponds to the desired pattern of a toothbrush. A tuft picker separates individual tufts from a filament magazine and a filling tool introduces the tufts into the holes of the carrier plate. For a complete set of tufts in a tuft pattern the carrier plate is successively moved in mutually perpendicular directions to precisely align each hole of the carrier plate with the filling tool. To achieve a high productivity, a high performance mechanism is needed for rapid and precise positioning of the carrier plate relative to the filling tool. A complete set of tufts is then either directly transferred to a molding machine where brush bodies or parts of brush bodies are molded and one end of the tufts is embedded in the molding material, or the tufts are attached to a member such as a platelet for later incorporation in a brush body either by molding the brush body around the member or by attaching the member to a preformed brush body.

[0003] It is generally possible with such a method to produce brushes with tuft patterns composed of different kinds or colors of filament, different tuft configurations and different shapes or sizes of the tufts. Larger tufts or tufts with an elongated cross-section can be obtained by joining multiple small tufts in a guiding channel. Larger tufts can also be produced by varying "on the fly" the size of the notch in the tuft picker. From a practical point of view, however, the freedom to combine different kinds of filament in a tuft pattern and to vary the shape, size and configuration of the tufts is limited by the performance of the tufting tool and tuft picker, and by and the space available for accommodating plural filament magazines with different kinds of filament. A further limitation is the time required for precisely moving and aligning the carrier plate hole by hole with respect to the filling tool, thus limiting the capacity of the machine.

[0004] The present invention provides a method and machine for producing brushes with an unlimited variability regarding the composition and configuration of the tuft patterns at high productivity and relaxed requirements to the carrier positioning mechanism.

[0005] Specifically, the invention provides a method of producing brushes comprising tuft patterns composed of tufts that may differ in at least one of shape, color, filament type, filament thickness, filament length and filament finishing. A set of tufts is composed for each brush to be produced by inserting tufts into holes of a carrier arranged in a pattern corresponding to the desired tuft pattern. The carriers are moved successively through a number of successive tufting stations. A single tuft is filled into a particular one of the carrier holes in each of the tufting stations. The tuft pattern in each carrier is thus successively composed by moving the carrier through the number of tufting stations. The set of tufts is ultimately joined with a brush body by one out of several possible methods.

[0006] Since the number of tufting stations with associated filament magazines in a tufting chain is on principle unlimited, the number of filament kinds that can be combined in a tuft pattern is also unlimited. Each tufting station has a filling tool associated with exactly one hole of the carrier, and only the carriers are to be moved from one tufting station to the next. Rapid and precise positioning of the carriers is easily achieved in comparison to the conventional positioning mechanism that needs to rapidly and very precisely move the carrier by small amounts under a filling tool to successively expose each hole to the filling tool.

[0007] The invention also provides a machine for producing brushes which is particularly useful in practicing the above method. The machine has a plurality of carriers each with a pattern of holes corresponding to a desired tuft pattern of a brush to be produced, and a number of tufting stations arranged in a succession. A transport mechanism moves the carriers successively through the tufting stations. A tuft filling tool in each tufting station fills a single tuft into a particular one of the carrier holes from an associated filament magazine of the tufting station.

[0008] Each tufting station needs to be adjusted only once in an initial set-up for a tuft pattern to be produced so that the filling tool in the station is aligned with just one of the holes of the carrier. The station's tuft picker also needs to be adjusted only in an initial set-up for the intended size of tuft, which can be different between the stations.

[0009] Basically, the transport system for the carriers can be implemented in two ways.

[0010] In a first embodiment a linear drive system is used which allows each carrier to move independently of all others in a programmed manner. Such a drive system can be seen in http://www.jacobsautomation.com/video.html. In this embodiment, the filling tools are closely and preferably equally spaced along the common transport path. The longitudinal target positions for the carriers relative to the filling tools are programmed into the system, and the transverse positions of the filling tools are adjusted to the needs of the tuft pattern. This way, the carriers are always moved precisely to the target positions where one tuft hole is aligned with the axis of an associated filling tool.

[0011] In a second embodiment, a common transport system such as a chain in a continuous loop is used and the carriers attached to the chain are moved by equal increments. In this case, the longitudinal positions of the filling tools along the chain are adjusted to align the axis of each filling tool with one of the tuft holes in a carrier that has been moved to that filling tool. In this case, too, the transverse positions of the filling tools are adjusted to the needs of the tuft pattern.

[0012] The machine of this invention is modular in nature in that the tufting stations may be identical and variable in number according to the needs. It is even possible to perform an automated or electronically assisted machine-setup for a particular tuft pattern to be produced by providing the filling tools with controllable positioning and aligning mechanisms (mechanical, pneumatic, hydraulic, electronic or electromagnetic).

[0013] Further advantages and features of the invention will become apparent from the following detailed description with reference to the appending drawings. In the drawings:

Fig. 1 is a perspective view of a toothbrush head;

Fig. 2 is a schematic perspective view of a section in a tufting chain;

Fig. 3 is a schematic view illustrating a tufting process;

Fig. 3a is a schematic view illustrating an alternative tufting process;

Fig. 4 is a schematic plan view of a tufting and processing chain where carriers can be moved in different cycles between tufting stations and processing stations although they are indexed by equal increments between the tufting stations; and

Fig. 5 is a schematic plan view of a tufting and processing chain with individually moving carriers.

[0014] The toothbrush head in Fig. 1 is for the purpose of demonstrating the large variety of tuft patterns, tuft configurations and material compositions achieved with the inventive method. In the illustrative example, a limited number of nine tufts is shown which differ from each other in shape, composition and color. In an actual toothbrush, many more tufts would form a tuft pattern, and many would be similar in shape, color and material. However, the inventive method allows combining any kind of tuft shape, color, material etc. with more conventional configurations, and even configurations with mostly or entirely similar tufts, as will become apparent from the following description.

[0015] Fig. 2 shows an essential part of a toothbrush making machine, which is the tufting chain, a section of which is shown which comprises three tufting stations. In Fig. 3, the tufting stations are designated A, B and C. Each tufting station has a filament magazine A1, B1, C1 and a tuft filling tool A2, B2, and C2. Each filament magazine A1, B1, C1 has a tuft picker, A11, B11 and C11, respectively. Each filling tool A2, B2 and C2 has a tuft pusher A12, B12 and C12, respectively. Carrier blocks 10, 12 and 14 are shown which each have a pattern of tuft receiving holes that corresponds to the tuft pattern of the toothbrush of Fig. 1. Carrier blocks 10,12 and 14 are precisely positioned in the tufting stations A1, B1 and C1, respectively. Between carrier blocks 12, 14 and 14, optional intermediate carrier blocks of identical configuration may be present, as shown in Fig. 2, and in fact, there could be any number of such intermediate carrier blocks or no such intermediate carrier block, as long as each carrier block, when positioned in one of the tufting stations A1, B1, C1, or any other tufting station of the entire tufting chain, is precisely positioned to align just one of its tuft holes with the axis of an associated filling tool. The tufting stations with their filament magazines, tuft pickers and tuft filling tools are basically conventional, a description of these elements is found in the initially mentioned prior art documents. It is clear, however, that they should be of a rather compact design to fit into a tufting chain that has a large number of tufting stations as may be required by a particular desired tuft pattern.

[0016] The operation of the tufting stations is illustrated more in detail in Fig. 3.

[0017] In Fig. 3, the upper row shows the carrier blocks of Fig. 2 in plan view, the intermediate row shows the corresponding tuft filling tools in cross-section and the bottom row shows the carrier blocks in cross-section.

[0018] In tufting station A, a tuft 20 separated from the filaments in filament magazine A1 is pushed by tuft pusher A12 through a channel in a guiding block A14 into a corresponding tuft receiving hole 30 of carrier block 10, the result is seen in intermediate carrier block 10a where tuft 20 sits in the corresponding hole. Likewise, in tufting station B, a tuft 22 separated from the filaments in filament magazine B1 is pushed by tuft pusher B12 through a channel in a guiding block B14 into a corresponding tuft receiving hole 32 of carrier block 12, which has already hole 30 filled with tuft 20, and the result is seen in intermediate carrier block 12a where tufts 20 and 22 sit in the corresponding holes. And in tufting station C, a tuft 24 separated from the filaments in filament magazine C1 is pushed by tuft pusher C12 through a channel in a guiding block C14 into a corresponding tuft receiving hole 34 of carrier block 14, which has already hole 30 filled with tuft 20 and hole 32 filled with tuft 22, and the result is seen in intermediate carrier block 14a where tufts 20, 22 and 24 sit in the corresponding holes. For the purpose of illustration, the upper row in Fig. 3 shows the tuft filling holes in solid black which have a tuft filled in.

[0019] It can be useful to have a filament magazine of a type that can provide different types of fibre to its associated filling tool, so that the machine can produce a mix of brushes with e.g. differently coloured filaments.

[0020] The filament magazine can also be equipped with a filament finishing unit that will treat the filaments that will be presented to the associated filling tool ; such treatments could be end-rounding of the fibre tips, or splitting the fibre tips. Equipping the filament magazine with such a filament treatment device will make sure that the brushes do not need any further treatment once they leave the machine.

[0021] The carrier blocks in the preceding description should be understood as items the exact nature of which depends on the technology used for producing the final brushes. Basically, the following methods are useful:

• transferring the tufts from the carriers to a platelet, attaching the tufts to the platelet by fusing their ends, and incorporating the platelet with the attached tufts in a brush body or a part thereof;
• transferring the tufts from the carriers to a mould using movable mold inserts, so that the tufts are incorporated with the brush body by molding;
• using at least part of a brush body as carrier and attaching the tufts to that part.

[0022] Most of the technological alternatives are also apparent from the initially mentioned prior art documents. During the transfer of the tufts into the platelet or to the mould, several advantageous options can be used, described in more in detail in the aforementioned prior art documents. For example, individual tufts in the carrier plate can be joined in order to join bigger tufts, specially shaped tufts, or tufts consisting of different kinds of fibre. Also tufts that are all parallel to each other in the carrier plate can be angled versus each other when they are in their final configuration.

[0023] In the embodiment of Fig. 3, the carriers move in equal steps from one tufting station to the next. This is easily achieved with a common drive chain that moves the carrier blocks successively through the row of tufting stations in equal incremental steps so that each carrier block is positioned in each of the tufting stations. Each tuft filling tool is precisely positioned and aligned with respect to a single one of the tuft receiving holes in each carrier block that has been moved to a corresponding tufting station, and each tuft filling tool is aligned with a different one of the tuft receiving holes with respect to all other tuft filling tools.

[0024] In the embodiment of Fig. 3a, the tuft filling tools are equally spaced a distance "d" and the carriers are driven by a linear transport system that allows the carriers to move precisely to predetermined target positions where the carrier has one of its holes aligned with the axis of a filling tool in one of the tufting stations. These target positions are programmed into the linear transport system as part of an initial setup of the machine where also the transverse positions of the filling tools are adjusted in relation to the particular tuft pattern to be produced. Except for the equal spacing of the filling tools and the consequential individual movements of the carriers, the operation of the tufting stations is similar to that described with respect to Fig. 3.

[0025] In Fig. 4, a processing machine is schematically shown in a plan view. The processing machine has a transport system with a closed-loop transport chain 40. In the example shown, the transport chain 40 is elongate and has a large number of tufting stations T1 to T40 on one side and four processing stations P1 to P4 on the other side. These processing stations P1 to P4 may be similar and can perform various subsequent steps in the production of toothbrushes. In particular, pushing the filaments into the topography of the eventual brush, cutting the filaments to the appropriate length, transferring the filaments into part of the brush body, and fusing or gluing the filaments together. Such processes can happen with the filaments still in the carrier plate, or once the filaments are already transferred to a next station, without falling outside the scope of this patent application. Once the carrier plates are emptied of their filaments, they may have to be cleaned and/or inspected before they are brought to the filling tools again. In case the carrier plates already contain a part of the brush head during the tufting cycle, such parts of the brush will have to be placed into the carrier plates again. Such processes will take longer than just adding another tuft to one of the carrier plates, so these processes will happen with several carrier plates simultaneously. After this longer process, the carrier plates will have to be transported further in a bigger step. For this movement, the chain is driven by a second drive system which operates independently of the first one.

[0026] Accordingly, although the common transport chain 40 in Fig. 4 moves the carriers by equal increments between the tufting stations T1 to T40, it permits different cycle times in the processing stations P1 to P4 by virtue of moveable sprocket wheels of the chain drive. In other words, while the carriers are indexed through the tufting stations T1 to T40 by equal increments corresponding to a short cycle time, a number of such carriers with completed tuft patterns need a substantially longer cycle time in each of the processing stations P1 to P4, and the corresponding chain links will be kept stationary during that longer cycle time.

[0027] Each of the processing stations P1 to P4 in Fig. 4 includes a carousel with a first sub-station S1 which disconnects carriers filled with tufts from the common chain 40, a second sub-station S2 which transfers the tufts from a carrier to a platelet supplied from an automatic platelet feeder F1, a third sub-station S3 where the platelet is joined with a brush head or brush body supplied from an automatic body feeder F2, and a fourth sub-station S4 where the emptied carriers are inspected, cleaned and prepared for further use in the machine.

[0028] It should be clear that the sub-stations in Fig. 4 are examples of sub-processing stations that ultimately produce finished toothbrushes.

[0029] In the embodiment of Fig. 5, a common linear transport system 60 is used wherein the carriers are each connected to a transport member capable of moving each carrier individually to predetermined target positions that are programmed into the transport system as explained in relation to Fig. 3a. The transport system is also elongate and has a number of tufting stations T1 to T6 on one side and processing stations A, B and C on the opposed side. It is seen that the carriers are positioned in different relative positions in each of the tufting stations T1 to T6. On the side of the processing stations A, B and C, which can be similar with those in Fig. 4, the timing of processing can be even more flexible since the carriers can all move independently of all others.

[0030] As is seen in Fig. 4, the number of tufting stations in the machine is quite high, as many as forty stations T1 to T40 being shown. It is in fact preferred that the number of tufting stations in the machine is at least the number of tufts in a tuft pattern to be produced. Using such a high number of tufting stations results in a high productivity of the machine which is an advantage even if the tuft pattern to be produced on the machine consists of only a few different kinds of tufts or even a single kind of tufts.

Claims

1. A method of producing brushes comprising tuft patterns composed of tufts that may differ in at least one of shape, color, filament type, filament thickness, filament length and filament finishing, wherein a set of tufts is composed for each brush to be produced by inserting tufts into holes of a carrier arranged in a pattern corresponding to the desired tuft pattern, and wherein the set of tufts is ultimately joined with a brush body;
the method comprising the steps of
providing a number of tufting stations;
moving the carriers successively through the tufting stations;
filling a single tuft into a particular one of the carrier holes in the tufting stations;
successively composing the tuft patterns in the carriers by exposing each carrier hole to an associated one of the tufting stations.

2. The method of claim 1 wherein each tufting station separates a single tuft from an associated filament magazine for filling into the particular one of the carrier holes.

3. The method according to claim 1 or claim 2, wherein a plurality of carriers are moved in a row through the number of tufting stations.

4. The method of claim 3 wherein the carriers are moved by a common transport system in equal increments between the tufting stations.

5. The method of claim 4 wherein the carriers are removably connected to the common transport system.

6. The method of any of claims 2 to 5, wherein the carriers are moved by a linear transport system which allows each carrier to move independently of all others to precisely defined longitudinal positions.

7. The method of claim 6, in which the predefined longitudinal positions are programmed in the transport system.

8. The method of any preceding claim wherein joining of the tuft patterns with a brush body is performed by either of

- transferring the tufts from the carriers to a member that is later incorporated in a brush body, and attaching the tufts to said member,

- transferring the tufts from the carriers to a mold where the tufts are incorporated with the brush body by molding,

- using at least part of a brush body as carrier or a part thereof and attaching the tufts to said part.

9. A machine for producing brushes comprising tuft patterns composed of tufts that may differ in at least one of shape, color, filament type, filament thickness, filament length and filament finishing, comprising
a plurality of carriers each with a pattern of holes corresponding to at least one desired tuft pattern,
a number of tufting stations arranged in a succession,
means for moving the carriers successively through the tufting stations,
a filament magazine in each tufting station,
a tuft filling tool in each tufting station for filling a single tuft into a particular one of the carrier holes from the filament magazine of the tufting station.

10. The machine according to claim 9, and further comprising a common transport system for moving the carriers in synchronism and in equal increments.

11. The machine according to claim 9, and further comprising a linear transport system which allows each carrier to move independently of all others to precisely defined longitudinal positions

12. The machine according to claim 10, in which the predefined longitudinal positions are programmed into the transport system.

13. The machine according to any of claims 9 to 12, wherein the transport system forms a closed-loop.

14. The machine according to any of claims 9 to 13, wherein the carriers are releasably coupled to the transport system.

15. The machine according to any of claims 9 to 14, wherein each tufting station has positioning and alignment means for positioning and aligning the tufting tool with respect a particular one of the holes in each carrier.

16. The machine according to claim 15, wherein the positioning and alignment means are controllable for adjusting the tufting tools in accordance with different desired tuft patterns.

17. The machine according to any of claims 9 to 16, wherein the carriers are moved to different kinds of processing units arranged with the tufting stations along a common transport path.

18. The machine according to any of the claims 9 to 17, wherein at least one filament magazine can supply filaments of different types to its associated filling tool.

19. The machine according to any of the claims 9 to 18, wherein at least one filament magazine has an integrated filament processing unit such as an end-rounding device to polish the tips of the filaments,

Drawing