Manual device for applying a coating on a substrate using a tape, having an improved end piece

Abstract

A manual device for applying a coating on a substrate by means of a tape has an applicator endpiece assembled to a casing and projecting from the casing. The applicator endpiece extends along a longitudinal direction and a lateral direction. The applicator endpiece has an attachment portion for assembling it to the casing, an applicator portion for applying the coating on the substrate, and a stem extending along the longitudinal direction between the attachment portion and the applicator portion. The stem is elastically deformable in such a manner that the applicator portion is movable between a rest position and an application position. The stem is an iso-stress stem.

Claims

1. A manual applicator device for applying a coating on a substrate by means of a tape, comprising: an applicator endpiece assembled to a casing and projecting from the casing, said casing having a first abutment and a second abutment, the applicator endpiece extending along a longitudinal direction and a lateral direction, the applicator endpiece comprising an attachment portion for assembling it to the casing, an applicator portion for applying the coating on the substrate, and a stem extending along the longitudinal direction between the attachment portion and the applicator portion, the stem being elastically deformable in such a manner that the applicator portion is movable between a rest position and an application position, the stem being an iso-stress stem, wherein the attachment portion further includes an oblong-shaped bar extending in the lateral direction, and wherein the oblong-shaped bar includes opposing end plates that form shoulders configured for limiting engagement in the lateral direction, wherein the second abutment cooperates with the applicator portion in the rest position by pressing thereagainst, whereby the stem in the rest position is prestressed in bending in a direction that is perpendicular both to the longitudinal direction and to the lateral direction.

2. A manual device according to claim 1, wherein the stem presents a cross section that is strictly decreasing in the longitudinal direction going from the attachment portion to the applicator portion.

3. An applicator device according to claim 1, wherein the first abutment is configured, when the applicator portion passes from the rest position to the application position, to limit the movement of the applicator portion in a direction that is perpendicular both to the longitudinal direction and to the lateral direction.

4. An applicator device according to claim 3, wherein between the first abutment and the applicator endpiece there is a clearance that in the rest position is greater than or equal to 1.0 mm.

5. An applicator device according to claim 1, wherein the bending stiffness of the stem lies in the range 0.13 N/mm to 1.35 N/mm, while the application pressure required for applying the coating of the tape on the substrate lies in the range 0.10 MPa to 1.02 MPa.

6. An applicator device according to claim 1, wherein the casing presents an intermediate portion, said intermediate portion presenting a wall designed to face the substrate during application, said wall presenting a curved shape, the applicator portion in the rest position being arranged at least partly outside the curve resulting from geometrically extending the curved shape of the wall, and inside the curve in the application position.

7. An applicator device according to claim 1, wherein the applicator endpiece presents an applicator edge, while the casing presents an intermediate portion and a distal end portion separated by a junction, an angle between a straight line passing through the applicator edge and the junction between the intermediate portion and the distal end portion of the casing, and the longitudinal direction is greater than 40 in the application position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and its advantages can be better understood on reading the detailed description of various embodiments of the invention given as non-limiting examples. The description refers to the accompanying sheets of figures, in which:

(2) FIG. 1 shows a manual device seen in perspective;

(3) FIG. 2 shows the FIG. 1 manual device, in an exploded view;

(4) FIG. 3 shows a detail of the endpiece assembled to a shell of the casing;

(5) FIG. 4A shows the shape of the endpiece both when it is not subjected to any stress, and also when it is subjected to a bending stress;

(6) FIG. 4B shows the endpiece as seen looking along arrow B of FIG. 2

(7) FIG. 5A shows the position of the manual device relative to a substrate on moving closer to the substrate; and

(8) FIG. 5B shows the position of the manual device relative to the substrate during application on the substrate.

DETAILED DESCRIPTION OF EMBODIMENTS

(9) An embodiment of the manual device of the invention for applying a coating on a substrate by means of a tape is described with reference to FIGS. 1 to 5B.

(10) FIG. 1 shows a manual device 10 for applying a coating on a substrate by means of a tape, seen in perspective. The manual device 10 comprises a casing 12, in this example an outer casing 12, an applicator endpiece 14 projecting from said casing 12 and a tape 16, said tape 16 including a coating (not shown) configured to be transferred onto a substrate. In this example, the casing 12 forms a grip handle for manipulating and using the manual device 10.

(11) The casing 12 is substantially crescent shaped, presenting a first distal end 12a from which the endpiece 14 extends and a second distal end 12b opposite from the first distal end 12a. In use, the concave side of the crescent shape faces away from the substrate, and consequently, the convex side is arranged facing the substrate. From the second end 12b to the first end 12a, on the concave side of the crescent shape, the casing 12 presents a bulge (or convex shape) 12c followed by a recess (or concave shape) 12d and by a bearing portion 12e. The bearing portion 12e is configured to hold the user's thumb during use of the manual device 10. In general, on its side facing away from the substrate during use, the manual device 10 presents a bearing portion for holding the user's thumb during use.

(12) As can be seen in FIGS. 5A and 5B, the portion of the casing 12 presenting the distal end 12a forms the distal end portion 12aa. The casing 12 also presents an intermediate portion 12f that is adjacent to the distal end portion 12aa and that is separated from the distal end portion 12aa by a geometrical discontinuity 12g. The face 12ff of the intermediate portion 12f facing the substrate S during application presents a curved shape, in this example a circularly arcuate shape having a radius lying in the range 15 mm to 25 mm, the center of curvature naturally being disposed on the side of the casing 12 that is remote from the substrate S.

(13) In this example, the casing 12 comprises two half-casings 12I and 12II housing reels 18a and 18b respectively for paying out and for taking up the tape 16, and a mechanism 20 associated therewith. In this example, the mechanism 20 is a mechanism having wheels that are coupled in rotation by a belt, but any other type of mechanism could naturally be envisaged. It should be observed that the tape 16 is paid out from the reel 18a in such a manner that the coating (not shown) faces outwards, extends longitudinally around the endpiece 14 by wrapping over a stem 14c of the endpiece (described below) so as to go around an applicator portion 14b of the endpiece 14 (described below), and is wound onto the takeup reel 18b. In FIG. 2, the arrows on the tape 16 indicate the direction of unwinding.

(14) The casing 12 also houses a portion of the endpiece 14. More particularly, the endpiece 14 extends in a longitudinal direction X and in a lateral direction Y, and comprises an attachment portion 14a, an applicator portion 14b, and a stem 14c connecting the attachment portion 14a to the applicator portion 14b. The attachment portion 14a is configured to assemble the endpiece 14 to the casing 12. The stem 14c extends longitudinally between the attachment portion 14a and the applicator portion 14b. The applicator portion 14b is configured to apply the coating of the tape 16 on a substrate. In this example, the attachment portion 14a and the stem 14c are housed completely inside the casing whereas the applicator portion 14b extends in part outside the casing 12. The applicator portion 14b includes an applicator edge 14ba extending in the lateral direction Y, this applicator edge 14ba being configured to co-operate with the tape by bearing against the face of the tape that is opposite from its face carrying the coating. In this example, the applicator edge 14ba is distinct from the distal end of the endpiece 14. Naturally, in a variant, the distal end of the endpiece and the applicator edge coincide.

(15) The stem 14c is elastically deformable and it is a iso-stress stem. Thus, below, and unless specified to the contrary, whatever the state of bending of the stem 14c, the longitudinal direction X of the endpiece 14 is the direction that passes through a first reference point of the attachment portion 14a and through a second reference point of the applicator portion 14b. By way of example, the first reference point is stationary during bending of the stem 14c. In this example, the first reference point is the mid-point C of the segment [AB] defined by the intersection between the straight line G extending the neutral axis F of the stem 14c when the stem 14c is not bent (position shown in continuous lines in FIG. 4A) and the general outside shape of the attachment portion 14a in the connection zone between the stem 14c and the attachment portion 14a (see FIG. 4B). The second reference point is the point of intersection E between the straight line G extending the neutral axis F of the stem 14c when the stem 14c is not bent, and the distal end portion 15 of the applicator portion 14b.

(16) In this example, as can be seen in FIGS. 4A and 4B, the stem 14c presents a cross section that is strictly decreasing going from the attachment portion 14a to the applicator portion 14b. In this example, the cross section is elliptical in shape.

(17) By means of the elasticity of the stem 14c, the applicator portion 14b is movable, within the casing 12, between a rest position (see FIG. 5A) and an application position (see FIG. 5B). The shape of the endpiece 14 in the rest position is shown in FIG. 3, whereas the shape of the endpiece 14 in the application position is shown in dashed lines in FIG. 4A.

(18) The attachment portion 14a includes a bar 14aa extending in the lateral direction Y and presenting an oblong-shaped cross section. The ends 14aa1 and 14aa2 of this bar 14aa are engaged in respective housings 12Ia and 12IIa of the half-casings 12I and 12II and they co-operate by interfitting shapes with the walls of the housings. Thus, by means of this oblong shape, the bar 14aa is prevented from turning about the lateral direction Y. In this example, the end portions of the bar 14aa are fitted with snap-fastener portions in relief 14ab for fastening the bar 14aa by snap-fastening to each half-casing 12I and 12II, portions in relief of complementary shape that are not shown being formed in the walls defining the housings 12Ia and 12IIa. In addition, two endplates 14ac and 14ad form shoulders for limiting engagement in the lateral direction Y of each end 14aa1 and 14aa2 in the respective housings 12Ia and 12IIa. In addition, the endplate 14ad presents a cutout portion co-operating by interfitting shapes with a projection 12IIa1 extending in the lateral direction Y from the periphery of the housing 12IIa, whereby the endplate 14ad and the projection 12IIa1 form a keying system making it easier to mount the endpiece 14 correctly in the casing 12.

(19) Each half-casing 12I and 12II presents a first abutment 12Ib, 12IIb and a second abutment 12Ic, 12IIc opposite the first abutment. The endpiece 14 is disposed between the first abutments 12Ib, 12IIb and the second abutments 12Ic, 12IIc.

(20) The following description makes reference to FIG. 3 showing in more detail the arrangement of the endpiece 14 in the half-casing 12II, but naturally this description also applies to the half casing 12I, the abutments 12Ib and 12Ic being arranged symmetrically to the abutments 12IIb and 12IIc about the midplane extending along the longitudinal direction X and perpendicular to the lateral direction Y of the applicator portion 14b. The first abutment 12IIb is configured, when the applicator portion 14b passes from the rest position to the application position, to limit the movement of the applicator portion 14b in a direction that is perpendicular both to the longitudinal direction X and to the lateral direction Y. In the rest position, the first abutment 12IIb and the applicator endpiece 14, and more particularly in this example the applicator portion 14b, are spaced apart by clearance J. In this example, the first abutments 12IIb and 12Ib co-operate in abutment with the endpiece 14, and more particularly with the applicator portion 14b, in the vicinity of the connection between the stem 14c and the applicator portion 14b. More particularly, in this example, the first abutments 12IIb and 12Ib co-operate in abutment with the portion of the applicator portion 14b that is adjacent to the stem 14c. The second abutment 12IIc co-operates with the applicator portion 14b in the rest position by pressing thereagainst (position shown in FIG. 3), whereby the stem 14c in the rest position is prestressed in bending in the direction that is perpendicular both to the longitudinal direction X and to the lateral direction Y.

(21) FIG. 4A shows in continuous lines the endpiece 14 when it is not subjected to any stress, whereas it shows in dashed lines the endpiece 14 when the applicator portion 14b is in the application position, the stem 14c then being bent. Thus, in the rest position shown in FIG. 3, the endpiece 14 has an intermediate configuration between the two extreme configurations shown in FIG. 4A.

(22) In this example, the stiffness of the stem 14c in bending is 0.88 N/mm while the second abutments 12Ic and 12IIc impose a movement of 0.74 mm. Consequently, the prestress to which the stem 14c is subjected is of 0.88 N/mm0.74 mm=0.65 N.

(23) In addition, the clearance J between the applicator portion 14b and the first abutments 12Ib and 12IIb in the direction perpendicular to the longitudinal and lateral directions is 1.8 mm, whereby a force of 1.6 N is required to bring the applicator portion into the application position (i.e. pressing against the first abutments 12Ib and 12IIb so as to eliminate the clearance J). The force required for driving the mechanism 20 and to unwind the tape and for peeling off the coating from the tape 16 so as to transfer it onto a substrate (i.e. the force for depositing the coating on a substrate) is 0.7 N. In this example, the force required for bringing the applicator portion 14b into the application position is greater than the force required for depositing the coating on a substrate. Naturally, in a variant, the force required for bringing the applicator portion into the application position is less than the force required for depositing the coating on a substrate, thereby ensuring that it is impossible for the user to deposit the coating while the applicator portion is not in the application position.

(24) In addition, since the tape 16 has a width of 5.0 mm, and considering that the contact between the tape 16 and the substrate corresponds to a 0.2 mm arc on the surface of the applicator edge 14ba, which has a radius of curvature of 0.15 mm, the contact area between the tape 16 and the substrate is 1.0 mm.sup.2, whereby the application pressure required for applying the tape on the substrate is 0.7 N/1.0 mm.sup.2=0.7 MPa.

(25) As shown in FIG. 5A, in the rest position, the applicator portion 14b is partly outside the curve CC resulting from geometrically extending the curved shape of the wall 12ff of the intermediate portion 12f of the casing 12, which portion is designed to face the substrate during application. More particularly, in this example, the applicator portion includes bottom cheeks 14bb and top cheeks 14bc for guiding the tape 16, the bottom cheeks 14bb being partly outside the curve CC in the rest position. Such a configuration generates a degree of inconvenience for the user, who is unable to make contact with the applicator edge 14ba if the manual device is not sufficiently tilted relative to the substrate S. In other words, by means of this configuration, it is possible to make contact between the substrate S and the applicator edge 14ba only if the angle between the longitudinal direction X and the substrate S is greater than or equal to a predetermined value. In this example, the predetermined value of the angle is equal to 40.

(26) As shown in FIG. 5B, in the application position, the applicator portion 14b is arranged inside the circle CC. In addition, in the application position, the angle , between the longitudinal direction X and the straight line H passing through the applicator edge 14ba and the junction 12g between the intermediate portion 12ff and the distal end portion 12aa of the casing 12, is equal to 29. By means of this configuration, it is ensured that the angle is greater than or equal to the angle , so that the user adopts a position that is tilted relative to the substrate S and that favors depositing the coating carried by the tape 16 correctly on the substrate S. In FIG. 5B, the endpiece 14 is shown with the bottom cheeks 14bb in contact with the substrate S, but this configuration corresponds to the example in which the angle is at its minimum value when in the application position. Naturally, during application it is possible, and even preferable, to have the bottom cheeks 14bb separate from the substrate S, and consequently to increase the value of the angle , which generates application conditions that are even more favorable.

(27) Although the present invention is described with reference to specific embodiments, it is clear that modifications and changes may be made to these embodiments without going beyond the general ambit of the invention as defined by the claims. In particular, individual characteristics of the various embodiments shown and/or mentioned may be combined in additional embodiments. Consequently, the description and the drawings should be considered in a sense that is illustrative rather than restrictive.