MXPA99007864A - Method and device for trimming and end-rounding bristles - Google Patents

Abstract

A method of trimming and end-rounding bristles and a device for carrying out the method are provided. The method includes providing a group of elongated continuous filaments arranged so that the longitudinal axis of each of the filaments is substantially parallel to the longitudinal axes of the other filaments and so that the ends of the filaments define a plane;advancing the group of filaments to an end-rounding device;end-rounding the group of filaments;and cutting the filaments to define a bundle of end-rounded filaments having a predetermined length.

Description

- - METHOD AND DEVICE FOR GIVING FINISH, AND ROUNDING END OF PIGS.

The present invention describes methods and devices for finishing and rounding ends of bristles, for example, bristles used in toothbrushes.

Brushes of various types are formed by assembling a plurality of bristles, typically arranged in tufts, or a brush body so that the tips together of the brushes define a brushing surface. In many applications it is necessary to arrange the bristles with a uniform length (or in some cases of different lengths to form a contoured brushing surface). Some applications also require that the tips of the bristles are "rounded at their ends", that is, the shape of the tips is modified from the typical surface, flat tip, sharp cutting, which occurs after the finishing of a relatively hemispherical tip shape. The rounding of the ends is particularly important when the bristles are used in REF .: 31116 - - a toothbrush, since the sharp edges of the tips of the sharp bristles can contribute to gingival abrasion and / or cause discomfort to the toothbrush user.

The present invention provides an improved process for finishing and rounding the ends of the filaments, and cutting the rounded end filaments to a length to form bristles. The bristles are formed by the proportion of the filaments continuously from the bristle supply, the gathering of the filaments together to form a group of filaments arranged so that the longitudinal axis of each filament is substantially parallel to the longitudinal axes of the other filaments and the ends of the filaments define a rounded, flat end of the ends of the filaments as they are arranged in a group, and the cut of a length of the grouped filaments that define a cut bunch. Advantageously, if desired the filaments can be fed to the device from a spool or other packing in which the continuous filaments are wound or contained (for example, a roll not rolled), - and the cut bunches can be easily transferred to a deposit from which the sows are fed to a machine that makes the tufts.

In one aspect, the invention provides a method for finishing and rounding the ends of the bristles. The method includes, (a) providing a group of elongated continuous filaments arranged so that the longitudinal axis of each of the filaments is substantially parallel to the longitudinal axes of the other filaments so that the ends of the filaments define a plane; (b) providing a device for finishing and rounding the ends of the bristles including, (i) a filament advancing filament device constructed to receive the filament group from the guide structure and advance to the group of filaments, comprising a first pair of jaws that are fixed against vertical movement, and a second pair of vertically movable jaws, each of said first and second pair of jaws are movable between an open position in which the group of filaments moves axially with with respect to the jaws, and a closed position in which the jaws take the group of filaments; (ii) an end rounding device positioned to engage the ends of said elongated filaments when supplied by the guide structure and to round the tips of said ends; and (iii) a cutter constructed to cut said filaments at a predetermined distance from said ends of rounded tips to form a cut bunch of bristles of a predetermined length; (c) with the first pair of jaws in the open position, the second pair of jaws is closed to take the group of filaments; (d) moving the second pair of jaws vertically to advance the group of filaments towards an end rounder; (e) closing the first pair of jaws to take the group of filaments and thereby limiting the radial movement of the filaments; (f) contacting the free ends of the group of filaments with the end rounder to round the ends of the group of filaments; and (g) cutting the filaments with the cutting device, to define a bundle of rounded end bristles having a predetermined length.

- - In preferred embodiments, the cutting step is performed using a guillotine-type cutter and the end rounding is performed using an end, belt rounding. The guide structure includes a guide tube constructed to collect the filaments within the group, and an advance holder constructed to take the group of filaments and move the group of filaments to a position in which their ends are fitted with the rounded device of extremes. Additional preferred devices include a transfer holder constructed to fit the cut bundle and transfer the cut bundle to a predetermined location spaced from the device. When the continuous filaments are provided in the form of a roll or a spool, additional preferred devices include a plurality of rollers on which the continuous filaments are passed, when said device is in use, the rollers are constructed to direct the filaments inside the guide structure. The group of filaments includes a sufficient number of filaments to manufacture a plurality of toothbrushes. It is also preferred that the guide structure, the filament advancement device, the end-rounder, and the cutting device have a substantially vertical alignment.

In a further aspect, the invention provides a device for finishing and rounding the ends of bristles.

The method and device of the invention allows the filaments to be finished and round off their ends easily before joining a brush. By finishing and rounded the ends of the bristles before joining the bristles to a brush, an excellent rounding of the ends can be performed due to the expanded ability to select the desired dwell time and other parameters during the rounded the ends (if the rounded ends are made before the action to make the plumes, the dwell time is often determined by the speed of the machine that makes the plumes). On the other hand, the loss by finishing is reduced, and the efficiency of the brush manufacturing process can be considerably improved.

- - In another aspect, the invention provides a method for the formation of a toothbrush. The method includes finishing and rounding ends of a plurality of filaments as described above to form bristles having a predetermined length, which provides a toothbrush head, and mounting a plurality of bristles on the head of the toothbrush .

The invention also performs bristles having improved end rounded characteristics. The shape of the ends of the bristles can be determined, for example, the ends of the bristles can be flat, half spherical, pencil point or any desired conical shape, depending on how the machine is configured, and this it must be understood by a person skilled in the art.

The term "guillotine" is used herein to refer to a sheet that is constructed to shear through a plurality of filaments without substantial tearing or tearing of the filaments.

Other features and advantages of the invention will be apparent from the description of the preferred embodiment thereof, and from the claims.

Figure 1 is a schematic end view of a device according to an embodiment of the invention. Figure la is a detailed view of a portion of the device of figure 1 (for clarity purposes, the cutter mechanism is omitted in figure la). Figure Ib is a side view of the device of figure 1, showing the feeding path for elongated filaments wound on a reel. Figure 1 is a detailed end view of the device, showing the power path from above.

Figure 2 is a schematic top view of the cutter mechanism of the device of Figure 1. Figure 2a is a side view of the cutter mechanism. Figure 2b is an enlarged detailed view of a portion of the cutter mechanism.

- - Figure 3 is a top view of the lifting clip used in the device of Figure 1, in its open position. Figure 3a shows the lifting clip in its closed position. Figure 3b is a perspective view of the lifting clip in its closed position.

Figure 4 is a schematic side view illustrating the unfolding of the filaments during contact with the end rounder.

Figure 5 is a top view in the open position, Figure 5a is a top view in the closed position, and Figure 5b is a side view of the transfer transfer fastener used in Figure 1.

With reference to Figures 1-lc, a preferred device 10 includes a reel 12 (Fig. Ib) from which a plurality of continuous filaments 14 are pulled. From the reel 12, the filaments 14 pass through a series of guide rollers 16,18,20,22. The rollers have an axial cross-section in the form of a "bow tie" (see Fig. 1), so that the filaments are directed together towards the center of the surface of the roller, to collect them together. To increase this picking effect it is preferred that the additional rollers from the reel have a cross-section in the shape of a bow tie more inclined than those which are closer to the reel, so that the filaments passing through the successive rolls they are gradually collected closer and closer together. This arrangement has been found to effectively control "ungoverned" as the filaments do not roll up from the spool and pass through the process, which inhibits the tendency of the filaments to become bulky and resist feeding.

Next, the collected filaments 14 are fed into the guide tube 24 having a funnel-shaped portion 26 at its upper end to assist the guide and further collect the filaments so that they enter the guide tube 24. To initiate the process, the filaments are fed through the guide tube until their harvested ends exit the lower end 28 of the guide tube and pass through the fasteners 30 and the fasteners 32.

The ends of the filaments are then taken and held in this position by means of the holding clips 30 (figures 1 and 1). The riser fasteners 32 and fastening clips 30 are substantially identical and are shown in detail in Figures 3 and 3a and are described below. The fastening clips 30 are mounted in a stationary position, and do not move in the vertical plane. The jaws of the fastening clips open and close, as shown in Figure 3 and 3a, respectively, to take or release the group of filaments.

At this point, the device has been prepared for use, and the group of filaments can now be cut into rounded end lengths on substantially continuous bases, ie, without the repetition of the previous initial feeding process.

The filament group 14 is then taken by the upward fasteners 32, and released by the fastening holders 30. The upward fasteners 32, like the fastening holders 30, are movable between the open and closed positions shown in figures 3 and 3a. The upstanding fasteners 32 are also movable between a plurality of positions in the vertical plane, for example, a raised position (shown in Figure 1 and the) and several positions below, by a linear actuator. Preferably, the linear actuator includes a spherical movable support 34 driven by an actuator 36 such as a stepper motor or servo motor. To continue feeding the filament group 14 through the device, then the upward fasteners 32 move, still taking the group, from the raised position to a lower position. This feeds the group of filaments through the guide of the lower part 38. The guide of the lower part includes an opening slightly larger than the diameter of the group, through which the group extends. The guide of the lower part 38 is movable between a normal, raised position, in which this is outside the path of the cutting device, and a lower guide position, in which it guides the group of filaments during the rounding of the extremes. The guide of the lower part inclines, for example, a spring inclination towards its raised position (figures 1 and 1), and is pushed towards its lower position by means of the impulse of the rising fasteners 32. In its lower position, the bottom guide is positioned at a predetermined height above the end rounder, selected to optimize the degree of "extension" of the bristles during rounding of the ends, as discussed below.

Immediately before, or during, the action of lowering the filament group by the upward fasteners, the belt end roundper 40 is actuated, that is, the two motors 44, 46 (FIG. 1) that drive the rotation of the end rounders belts are turned on, It is preferred that the end rounder is actuated before any contact with the ends of the filament, otherwise the filaments may tend to curl in an undesired manner, eg twisting, or being forced back through the bra as the actuator raises the ball thread. If desired, the end rounder can be operated continuously so that it is not necessary to coordinate the turns of the end rounder with the decrease of the group of filaments.

Preferably, the fastening fasteners 30 approaches before the ends of the group of filaments are fitted with the end round, belt, to stabilize the group of filaments during the rounding of the ends.

When the ends of the group of filaments are brought into contact with the belt 42 of the end round, the ends extend as shown in Figure 4. The extent to which these extend outwards will be at least to some degree determinative of the degree of rounding of ends that can be performed in a given amount of time. The extension of the extension is determined by several factors: (a) the length of the group of filaments that extend below the guide of the bottom 38, (b) the diameter of the group, as well as the diameter of the individual filaments , (d) the "interference distance" between the group of filaments and the belt, that is, the amount by which the group of filaments - - could be extended below the rounded end, belt, if there was an opening in the belt through which the group could be extended (the filaments are instead pushed outward by the pressure exerted against the belt), (e) the impulse velocity of the ends rounded belts, and (f) ) the roughness of the surface of the ends rounded belts. The impulse velocity is often dictated by the speed required to keep pace with the other steps in the brush manufacturing process. To obtain a good rounding of ends, it is desirable to have the ends of the filament "walking around a circle" on the surface of the belt during the rounded ends. If the ends of the filaments do not move around the surface of the belt in any way, generally the ends of the flat filaments are only flattened with sand or sand, instead of the rounded ends. The above factors can be adjusted empirically to obtain the desired degree of rounding of ends by observing the condition resulting from the ends of the filaments after the completion of the process and by the variation of any or all of these parameters - as needed , and must be understood by anyone skilled in the art.

Preferably, an empty coating is provided adjacent to the end rounder, to remove the dust generated during rounding of the ends, as is well known in the art.

After the ends of the group of filaments 14 have been rounded from the ends, the group of filaments is raised to a predetermined position relative to the cutting device 48 by the upward fasteners 32 in preparation for cutting a length of the filaments of Rounded ends for use as bristles. The predetermined position is determined by the length of the sow that is desired.

When the group of filaments is in the desired position, it is taken by the up and holding clips above the cutting device, and by a transfer holder 70 (shown in detail in FIGS., 5a, 5b) below the cutting device. That holds the group of filaments above the device - - cutter that ensures an exact cut to the desired length. Additionally, the fasteners hold the desired position of the filament after cutting. Holding the group of filaments below the cutting device allows the cut portion of the group to be held together and transferred to another location, for example, towards a deposit of the filaments. In a manufacturing process of a toothbrush, the cut portion must be transferred to a filament deposit in a tufting station.

Then the cutter device, shown in Figures 2-2b, is actuated. The cutting device includes a plate 50 having a cutting opening 52 for receiving the group of filaments. The cutting opening 52 includes a bevel 54 which is angled to direct the ends of the filament within the opening. The guillotine blade 56 reciprocates between a normal position (shown in solid lines in Figure 2) and a cutting position (shown in dashed lines in Figure 2) in the guillotine shape. The inventors have found that, by cutting the filaments in this manner, uniform flat ends are obtained without breaking the filaments. This result remains relatively consistent even after sheet deterioration or wear occurs. The guillotine blade 56 includes an angled cutting blade 58 (Figure 2b), for additional assurance that the filaments are cut cleanly rather than broken.

The reciprocating movement of the guillotine blade is driven by the rotation of the crankshaft 59 (FIG. 2), which displaces the eccentric cam 60 from the position shown in solid lines through the positions shown in dashed lines in FIG. 2. The eccentric cam, on the other hand, displaces the bearing 62 against the tilting spring 64 (which tilts the guillotine blade 56 towards its normal position), forcing the blade of the front guillotine through the group of filaments.

As noted above, the upstanding fastener 32 and the holding fastener 30 are substantially identical. Accordingly, both are shown in Figures 3-3b. These figures are described with reference to the rise fastener, for convenience; - - The following description, however, applies to both holders.

A riser 32 includes a pair of jaws 66a, 66b, which move between the open (Figure 3) and closed (Figures 3a, 3b) positions by means of a pneumatic fastener 68. The jaws 66a, 66b, include the portions arched 70a, 70b which together define an opening 72 of variable diameter. When the lifting clip is in its open position (FIG. 3), the diameter of the opening 72 is significantly larger than the group of filaments, which allows the holder to move axially up and down the length of the fastener. group of filaments. When the lifting clip is in its closed position (Figures 3a, 3b), the diameter of the opening 72 is substantially equal to the outer diameter of the group of filaments (in a compressed state), which allows the fastener to take on a secure way to the group of filaments. As shown in Figure 3b, the jaws 66a, 66b preferably include mating retention fingers 74 to enable the jaws to move between their positions in a controlled manner without loss of filament content.

The transfer holders 70, shown in Figures 5-5b, include a pair of jaws 76a, 76b that include the arcuate portions 78a, 78b, and an actuator 80 that moves the jaws between an open position (Figure 5) and a closed position (figure 5a). In the open position, the arcuate portions 78a, 78b are completely separate, that is, they do not define an opening. In the closed position, the arcuate positions 78a, 78b define an opening 82 having a diameter that is substantially equal to the external diameter of the cut bunch, which allows the fasteners 70 to firmly take the cut bunch.

The following example is intended to be illustrative and not limiting in effect.

EXAMPLE The continuous filaments of nylon of 7 thousand. in diameter, wound on a spool, are fed through the device shown in FIG. 1, in the manner described above. The interference distance is approximately 0.090 inches. The abrasive medium (ends rounded belt) is 280 granules of silicon carbide. The speed of the abrasive medium is about 70 inches / second, and the orbital velocity of the end-rounded head (rotation speed in the plane parallel to the plane defined by the ends of the filaments) is about 1000 rpm. The contact duration of the ends of the filaments with the abrasive medium is approximately 8 seconds.

The ends of the filaments are examined after the procedure is completed, and the ends consistently exhibit the desired shape. In this case a spherical middle end is desired.

Other embodiments are found in the claims.

For example, the end rounder does not need to be an end round belt, as shown, but can instead be any other device that produces the rounded ends of the selected filaments. Examples of other suitable end rounders include, but are not limited to, belt end routers; end rotators, drum; end rounds, chemical (for example an acid bath), heat end rounding and end rounding by ultrasound. Many types of filaments can be used, which allow the filament to have sufficient structural integrity to withstand the process, which can be easily determined empirically. When the bristles are to be used in the manufacture of toothbrushes, the filaments should be selected for such use. Suitable bristle materials for toothbrushes are well known to those skilled in the art. Further, although the filaments have been illustrated as being wound on a reel, the filaments may be provided in a different manner, the used feeding route may change (no more than the rollers illustrated in Figures 1-lc). For example, if an unwrapped roll of filaments is used, the filaments can be fed through an elongated tube.

It is noted that in relation to this date, the best method known to the applicant, to carry out the aforementioned invention, is that it is clear from the present description of the invention.

Having described the invention as above, property is claimed as contained in the following:

Claims (24)

- - CLAIMS
1. A method for finishing and rounding ends of bristles characterized in that it comprises: (a) providing a group of elongated continuous filaments, arranged in such a way that the longitudinal axis of each of the filaments is substantially parallel with the longitudinal axes of the other filaments; (b) providing a device for finishing and rounding the ends of the bristles comprising: a filament raising device constructed to receive the filament group from the guide structure and the rise of the group of filaments, comprising a first pair of jaws that are fixed against vertical movement, and a second pair of jaws vertically movable, each of the first and second pair of jaws are movable between an open position in which the group of filaments is axially movable relative to the jaws, and a closed position in which the jaws grip or hold the group of jaws. filaments; - a device for rounding ends arranged to fit the ends of said elongated filaments when they are supplied by said guide structure and for rounding the tips of said ends; and a cutter constructed to cut said filaments at a predetermined distance from the ends of rounded tips to form a cut bunch of bristles of a predetermined length; (c) with the first pair of jaws in the open position, the second pair of jaws is closed to take the group of filaments; (d) moving the second pair of jaws vertically to raise the group of filaments towards an end rounding device; (e) closing the first pair of jaws to take the group of filaments and thereby restricting the radial movement of the filaments; (f) contacting the free ends of the group of filaments with the end rounder to round the ends of the group of filaments; Y - - (g) cutting the filaments with the cutting device, to define a bundle of rounded end bristles having a predetermined length.
2. 2. The method of claim 1, further comprises a third pair of jaws constructed to take the group of filaments below the cutting device, and, during step (g), the fastening of the filaments above the cutting device with at least one of the first and second pairs of jaws and the clamping of the filaments below the cutting device with the third pair of jaws to stabilize the filaments, and cutting the bristles during and after cutting.
3. 3. The method of claim 1, characterized in that additionally comprises providing a third pair of jaws, constructed to take the group of filaments in a region below the cutting device, and take the group of filaments with the third pair of jaws before the cutting of the filaments. - -
4. 4. The method of claim 1, characterized in that it additionally comprises providing a guide member, mounted above the end rounder, and having an aperture sized to receive the group of filaments, and inserting the group of filaments through the member guide to further restrict the radial movement of the filaments.
5. 5. The method of claim 1, characterized in that it additionally comprises providing said elongated filaments wound on a reel.
6. 6. The method of claim 5, characterized in that it additionally comprises unrolling said elongated filaments from said reel.
7. 7. The method of claim 6, characterized in that said supply step comprises passing the elongated filaments through a series of rollers constructed to collect the filaments within said group. -
8. 8. The method of claim 1, characterized in that said cutting step is performed using a cutting device in the form of a guillotine.
9. 9. The method of claim 1, characterized in that it additionally comprises selecting the predetermined length so that the bristle is suitable for use as a bristle of a toothbrush.
10. 10. The method of claim 1, characterized in that it additionally comprises selecting said group of filaments to contain sufficient filaments to form a plurality of toothbrushes.
11. 11. A device for finishing and rounding the ends of bristles characterized in that it comprises: a guide structure constructed to supply a plurality of elongated continuous filaments in the form of a group arranged such that the longitudinal axis of each of the filaments is substantially parallel to the longitudinal axes of the other filaments; a filament raising device constructed to receive the filament group from the guide and rise structure of the filament group, comprising a first pair of jaws that are fixed against vertical movement, and a second pair of jaws vertically movable, each of said first and second pair of jaws is movable between an open position in which the group of filaments is axially movable with respect to the jaws, and a closed position in which the jaws take the group of filaments; an end rounding device positioned to fit the ends of said elongated filaments when supplied by said guide structure and to round the tips of said ends; and a cutter constructed to cut said filaments at a predetermined distance from said ends of rounded tips to form a cut bunch of bristles of a predetermined length. - -
12. 12. The device of claim 11, characterized in that said cutter is a guillotine-type cutter.
13. 13. The device of claim 12, characterized in that said guillotine-type cutter comprises a blade having an angled surface which faces from the direction from which the group of filaments is supplied to the cutting device.
14. 14. The device of claim 12, characterized in that said guillotine-type cutter comprises a cutting plate having a beveled cutting opening.
15. 15. The device of claim 12, characterized in that said guillotine cutter comprises a crankshaft; an eccentric cam mounted on said crankshaft for movements between the two positions in response to the rotation of said crankshaft; a guillotine blade mounted for movement, in response to the displacement of said eccentric cam, from a first, retracted position, to a second, -actuated position, in which the blade shears through the group of filaments.
16. 16. The device of claim 11, characterized in that each of said first and second pair of jaws comprises arcuate portions constructed to define an opening of variable size.
17. 17. The device of claim 16, characterized in that each of said first and second pairs of jaws comprise two opposed jaws, each jaw comprises said arcuate portion and a plurality of separate fingers, the fingers of one of the opposing jaws is placed with the fingers of the other opposing gag.
18. 18. The device of claim 11, characterized in that said guide structure comprises a guide tube constructed to collect said filaments within said group.
19. 19. The device of claim 18, characterized in that said guide tube includes a first end in which said first group of filaments enters the guide tube, said first end has a funnel-shaped portion for directing the filaments into the guide tube.
20. 20. The device of claim 11, characterized in that it additionally comprises a third pair of jaws constructed to fit the group of filaments below the cutting device and to transfer the cut bunch to a predetermined location separated from the device.
21. 21. The device of claim 11, characterized in that it additionally comprises a plurality of rollers on which the filaments are passed, when the device is in use, said rollers are constructed to direct the filaments inside the guide structure.
22. 22. The device of claim 21, characterized in that said rollers each have a surface shape that converges to drive the filaments together as they pass over each of the rollers.
23. 23. A device for finishing and rounding the ends of the bristles characterized in that it comprises: a guide structure constructed to supply a plurality of elongated continuous filaments in the form of a group arranged so that the longitudinal axis of each of the filaments is substantially parallel to the longitudinal axes of the other filaments and so that the ends of the filaments define a plane; an end rounding device positioned to fit the ends of said elongated filaments when supplied by the guide structure and rounding the tips of said ends; and a guillotine-type cutter for cutting the filaments at a predetermined distance from said ends of rounding of the tips to form a cut-off bunch of bristles of a predetermined length.
24. 24. A device for finishing and rounding ends of bristles characterized in that it comprises: - a guide structure constructed to supply a plurality of elongated continuous filaments in the form of a group arranged so that each of the filaments is substantially parallel to the axes longitudinal of the other filaments and so that the ends of the filaments define a plane; a filament raising device constructed to receive the filament group from the guide structure and go up to the filament group; an end rounding device positioned to engage the ends of said elongated filaments when supplied by the guide structure and to round the ends of said ends, and a cutter constructed to cut said filaments at a predetermined distance from said ends of rounded tips to form a cut bunch of bristles of a predetermined length, wherein the guide structure, the filament rise device, the end rounder, and the cutting device are aligned substantially vertically.