US20040150258A1 - Method and apparatus for making toothbrushes - Google Patents

Abstract

A method for making toothbrushes includes the steps of, providing a toothbrush, and providing an end-rounder secured to a support. The support is substantially fixed against movement The toothbrush is moved towards the end-rounder such that free ends of bristles secured to a head of the toothbrush are rounded by the end-rounder.

Description

FIELD OF THE INVENTION
• The invention relates generally to the field of toothbrushes, and in particular to toothbrush manufacturing.[0001]
BACKGROUND OF THE INVENTION
• FIG. 1 discloses a preexisting apparatus for making (finishing) toothbrushes. Pairs of[0002]toothbrushes10 are secured to blocks12. The toothbrushes are in nearly their final state of manufacture at this point with bristles secured to the heads of the toothbrushes. Achain14 periodically advances blocks12 in the direction of anarrow16.
• A group of five[0003]cutters18 are each used to trim or cut a subgroup of bristles on each brush to their specified length. A group of seven end-rounders20 are used to round off the cut free ends of various subgroups of the bristles.Chain14 advances all oftoothbrushes10 until they are properly positioned over a respective cutter or end-rounder.
• A plow or fork (not shown) is then inserted into the bristles of some, but not all, of the toothbrushes which are adjacent to a cutter or end-rounder. The plow bends some of the bristles on a brush out of the way so that other bristles on the brush can be trimmed or end-rounded as the case may be. A platform (support)[0004]22 is then raised to bring the cutters and end-rounders into contact with the bristles which are to be trimmed or end-rounded. It takes about 0.75 seconds to raise all the cutters and end-rounders.
• After the bristles are trimmed or end-rounded,[0005]platform22 is lowered to distance the cutters and end-rounders from the bristles.Chain14 then advances to move the toothbrushes to the next cutter or end-rounder in the finishing process. Although not shown, after the toothbrushes receive a final-end-rounding at the right-most end-rounder in FIG. 1, they are removed fromchain14 and packaged. These toothbrushes are replaced inblocks12 by new unfinished toothbrushes which have yet to be trimmed and end-rounded.
• A problem with this arrangement is that during the[0006]time platform22 is being raised and lowered, no end-rounding is being done on the bristles. Further, whilechain14 is advancing the toothbrushes into and out of a certain end-rounding station, no end-rounding is being done on the bristles. As a result, more aggressive end-rounding must be done during the limited time available to end-round the bristles. This requires plows (forks) to be inserted into the bristles at five of the seven end-rounding stations.
SUMMARY OF THE INVENTION
• The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, an apparatus for making toothbrushes includes an end-rounder for rounding the free ends of bristles secured to a head of a toothbrush. The end-rounder is secured to a support, the support being substantially fixed against movement.[0007]
• According to another aspect of the invention, an additional end-rounder is included for rounding the ends of bristles secured to the head of the toothbrush. The additional end-rounder is secured to an additional support. The additional support is moveable alternately towards or away from the toothbrush to move the additional end-rounder towards or away from the toothbrush.[0008]
• According to a further aspect of the invention, a cutter is provided for trimming the length of bristles on the toothbrush head prior to the ends of these bristles being rounded by the end-rounder. The cutter is moveable alternately towards or away from the toothbrush to move the cutter towards or away from the toothbrush.[0009]
• These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.[0010]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a schematic side view of a pre-existing apparatus for making/finishing toothbrushes;[0011]
• FIG. 2 is a schematic side view of an apparatus according to the invention for making/finishing toothbrushes;[0012]
• FIG. 3 is a bottom view of a bristle finishing fork inserted into a group of bristles;[0013]
• FIG. 4 is a sectional view of FIG. 3 taken along the lines[0014]4-4 of FIG. 3;
• FIG. 5 is a sectional view of a cutter as looking into the paper on which FIG. 2 lies;[0015]
• FIG. 6 is similar to FIG. 5 but also showing an end-rounder in operating position; and[0016]
• FIG. 7 is a perspective view of a bristle pattern on a toothbrush which can be made by the current invention.[0017]
DETAILED DESCRIPTION OF THE INVENTION
• Beginning with FIG. 2, reference numerals will be used that are similar to the reference numerals in FIG. 1 for those elements that are essentially the same. Pairs of[0018]toothbrushes10 are secured to blocks12. The toothbrushes are in nearly their final state of manufacture at this point with tufts of bristles secured to the heads of the toothbrushes. The bristle tufts may have various heights and orientations at this point.
• A[0019]chain14 periodically advances blocks12 in the direction of anarrow16. Each advance ofchain14 takes about 0.5 seconds. The chain stops moving when a pair of toothbrushes are adjacent to each of fivecutters18 and seven end-rounders20(a)-(g). The cutters and end-rounders are constantly running. The bristles on each toothbrush adjacent a cutter or end-rounder are facing down towards the cutter or end-rounder.
• Referring to FIGS. 3 and 4, a bristle finishing fork (or plow)[0020]30 is now inserted opposite the direction of anarrow31 intobristles32 betweenhead34 of the toothbrush and a respective one of the cutters or end-rounders. The fork bends a first sub-group ofbristles36 to the side while allowing a second sub-group ofbristles38 to project through agap40 in the fork. This arrangement allowsends40 ofbristles38 to be cut or end-rounded as the case may be while preventingends42 ofbristles36 from being cut or end-rounded.
• Forks are used on the first three cutters the toothbrush encounters but not the last two cutters. This is the same as for the FIG. 1 apparatus. Forks are only required if it is necessary to prevent some bristles from being cut or end-rounded while other bristles are cut or end-rounded. This all depends on the final topography of the bristles desired.[0021]
• Next, a[0022]pneumatic piston44 is actuated to pull apiston rod46 into the piston. This causes acam follower48 to move along acam path50.Cam follower48 is also linked to asecond cam follower52 which likewise moves along anothercam path54. The motion of the cam followers causes asupport56 to move up about 7 mm in about 0.6 seconds. The five cutters and 1^stend-rounder are connected to support56 and likewise move up with the support. This motion causes designated bristles to come into contact with the cutters and end-rounders.
• Turning now to FIG. 5, the operation of the cutters will be explained. Each[0023]cutter18 includes four rotatingtrimmer blades60 and astationary counter blade62. The act of raisingsupport56 causes bristles designated for cutting to move relative tocutter18 in the direction of anarrow64. Aftersupport56 stops moving up, all of thecutters18 are moved back and forth together in the direction of double-headedarrow64. Each movement is about 2.5 inches and the cutters make about 5 cycles back and forth. This movement of the cutters allows the designated bristles of both toothbrushes presented to each cutter to be properly trimmed. The cutting operation takes about 4 seconds. The orientation and/or position of a cutter can be adjusted to alter the angle of cut on the bristles.
• Referring to FIG. 6, end-rounder[0024]20(a) is also raised onsupport56. End rounder20(a) includes a partialspherical surface66 which has a roughened finish for abrading and rounding the free ends ofbristles38. The end-rounder is rotated in the direction of anarrow68 about anaxis70.Axis70 is also rotated aboutaxes72 and74. The resultant motion results in what is called an orbital end-rounder. Further details on this type of end-rounder and onfork30 can be found in U.S. Pat. No. 5,593,213.
• The remaining end-rounders[0025]20(b)-(g) are not connected to support56 and so do not move up or down with the support. Each end rounder20(b)-(g) is connected to anadditional support76 which is substantially fixed against movement. As such, these six end-rounders are already in position to end-round whenchain14 starts moving the toothbrushes. After end-rounding and cutting is complete,piston44 is actuated tolower support56 and thus lower the five cutters and the first end-rounder. This lowering operation takes about 0.5 seconds.
• Although not shown, after the toothbrushes receive a final-end-rounding at the right-most end-rounder[0026]20(g), they are removed fromchain14 and packaged. These toothbrushes are replaced inblocks12 by new unfinished toothbrushes which have yet to be trimmed and end-rounded.
• There are a number of advantages to thus fixing the last six end-rounders in position. End-rounding can now be done while[0027]chain14 is moving toothbrushes both into and out of a particular end-rounder, as well as during substantially all of thetime support56 is being raised and lowered. This adds about 1.5 more seconds of end rounding for each toothbrush at each of the six fixed end-rounders. Thus about nine more seconds of end-rounding are done on each brush. This additional end-rounding times allows end-rounding to be done less aggressively. As a result, none of end-rounders (b)-(g) requireforks30 to be used, resulting in a cost savings. In the system of FIG. 1, four of these six end-rounders required forks to be used. End-rounder20(a) still requires a fork because it is end-rounding the shortest bristles on the toothbrush.
• Another advantage is that[0028]support56 can be raised faster because it is lifting only one end-rounder instead of seven end-rounders. As a result,support56 can be raised in about 0.2 seconds.
• FIG. 7 shows a[0029]toothbrush80 which can be made by the method and apparatus described above. The bristle pattern is that of the Advantage® toothbrush sold by Oral-B®.Toothbrush80 includes ahead82 from which extends a group ofbristle tufts84 known as a “power tip”. The top surface oftufts84 angles down towardshead82. Another group of bristle tufts86define a “V” or “U” shapedgrove88 known as an “action cup”.
• The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.[0030]

Claims (15)

1. An apparatus for making toothbrushes, comprising:

an end-rounder for rounding the free ends of bristles secured to a head of a toothbrush; and

a support to which the end-rounder is secured, the support being substantially fixed against movement.

2. The apparatus ofclaim 1, further comprising:

an additional end-rounder for rounding the ends of bristles secured to the head of the toothbrush; and

an additional support to which the additional end-rounder is secured, the additional support being moveable alternately towards or away from the toothbrush to move the additional end-rounder towards or away from the toothbrush.

3. The apparatus ofclaim 2, further comprising:

means for moving the additional support towards or away from the toothbrush.

4. The apparatus ofclaim 1, further comprising:

a cutter for trimming the length of bristles on the toothbrush head prior to the ends of these bristles being rounded by the end-rounder, the cutter being moveable alternately towards or away from the toothbrush to move the cutter towards or away from the toothbrush.

5. The apparatus ofclaim 4, further comprising:

an additional end-rounder for rounding the ends of bristles secured to the head of the toothbrush; and

an additional support to which the additional end-rounder is secured, the additional support being moveable alternately towards or away from the toothbrush to move the additional end-rounder towards or away from the toothbrush, the cutter being secured to the additional support such that it moves with the additional end-rounder.

6. A method for making toothbrushes, comprising the steps of:

providing a toothbrush;

providing an end-rounder secured to a support, the support being substantially fixed against movement; and

moving the toothbrush towards the end-rounder such that free ends of bristles secured to a head of the toothbrush are rounded by the end-rounder.

7. The method ofclaim 6, comprising the further steps of:

providing an additional end-rounder for rounding the ends of bristles secured to the head of the toothbrush;

providing an additional support to which the additional end-rounder is secured;

moving the additional support towards the toothbrush such that free ends of bristles secured to the head of the toothbrush are rounded by the end-rounder.

8. The method ofclaim 7, comprising the further step of:

moving the additional end-rounder away from the toothbrush to disengage the bristle ends from the end-rounder.

9. The method ofclaim 6, comprising the further step of:

moving a cutter towards the bristles.

10. The method ofclaim 9, comprising the further step of:

trimming the length of bristles on the toothbrush head with the cutter prior to the ends of these bristles being rounded by the end-rounder.

11. The method ofclaim 10, comprising the further step of:

moving the cutter away from the bristles.

12. The method ofclaim 11, further comprising the step of:

providing an additional end-rounder for rounding the ends of bristles secured to the head of the toothbrush.

13. The method ofclaim 12, further comprising the step of:

providing an additional support to which the additional end-rounder is secured.

14. The method ofclaim 13, further comprising the step of:

moving the additional support alternately towards or away from the toothbrush to move the additional end-rounder towards or away from the toothbrush.

15. The method ofclaim 14, further comprising the step of:

securing the cutter to the additional support such that the cutter moves with the additional end-rounder.

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