Shafting structure of a coating tool

Abstract: A shafting structure for a coating tool adapted to transfer to a target object a paste or a correcting paint which is adhered to a transfer tape. The coating tool comprises a main body housing therein a supply reel (10) and a supply reel gear which are supported by the same shaft and a take-up reel and a take-up reel gear. The shafting structure is such that an annular rib (17) is formed on a cylindrical portion of the supply reel gear and a number of elastic frictional strips (15) for holding and engaging the supply reel gear is formed on the inner wall surface of an engagement hole (13) of the supply reel whereby holding and engagement of the supply reel gear by the elastic frictional strips of the supply reel is secured thereby allowing delivery and taking-up of the transfer tape in a smooth amnner whiel by preventing a thermal deformation of the elastic frictional strips.

Description: The present invention relates to a coating tool adapted to transfer to a target object a paste or a correcting paint or the like adhering to the surface of a transfer tape and in particular to a shafting structure of such coating tool. EP-A-0 362 697 discloses a coating tool according to the preamble of claim 1. In the case of a conventional coating tool which performs a coating operation by transferring to a target object a paste or a correcting paint adhered to the surface of a transfer tape, a take-up reel and a supply reel gear are mounted on the same shaft so as to rotate integrally with a supply reel gear or a take-up reel gear meshing with each other, relative to a supply reel shaft and a take-up reel shaft respectively. Especially, referring to the supply reel, in order to prevent a possible breakage or cutting of the transfer tape taking place when the unused transfer tape is drawn out with a strong tensile force so that only the supply reel rotates and an excessive degree of stress is applied on the transfer tape, it has been generally practised (EP 0 556 406 A) that the supply reel and the supply reel gear are made for common rotation with each other in such a manner that the supply reel gear is held clamped by a clutch mechanism having an O-ring as a friction member with respect to the supply reel gear whereby the supply reel may rotate relative to the supply reel gear when an above-described strong tensile force is applied on the transfer tape. The performance of such type of clutch mechanism is dependent on a proper fit of the O-ring with respect to the adjacent parts of the coating tool it cooperates with, and of an O-ring material which is not susceptible to change its elastic properties by time. Thus friction forces developed by O-rings often are too great or too low resulting in an unproper function of the coating tool. Moreover the overall structure of the coating tool and the assembly thereof become complicated. Due to thermal or otherwise deformation of the cooperating parts in other prior clutch mechanism undesired idle rotation of the supply reel with respect to the supply reel gear parts of the coating tool may occur. The present invention has been made to solve the above-described problems involved with the conventional coating tool. Namely an object of the present invention is to provide a coating tool which is simple in structure and which is capable of performing the delivery and taking up of the transfer tape smoothly and accurately, and any idle rotation of the supply reel with respect to the supply reel gear is prevented. This problem is solved in accordance with the present invention by the features of claim 1. Accordingly the coating tool comprises a clutch mechanism comprises an annular rib formed on the outer peripheral surface of the cylindrical portion of the supply reel gear or the take-up reel gear so as to surround the cylindrical portion, and elastic frictional strips formed on the lower portion of the inner wall surface of the engagement hole of the supply reel or the take-up reel so as to fit between the annular rib and the outer peripheral wall of cylindrical portion of the supply reel gear or the take-up reel gear. With the above-described structure, the elastic frictional strips hold and engage the cylindrical portion of the supply reel gear thereby allowing the supply reel to interlock with the supply reel gear. These strips are made small in thickness or made of a soft material so as to have a sufficient degree of elasticity so that even when the elastic frictional strip tends to become deformed by expanding outward, since the elastic frictional strip fits between the cylindrical portion of the supply reel or the take-up reel and the annular rib formed to surround the cylindrical portion of the supply reel gear or the take-up reel gear, a thermal deformation of the elastic frictional strips is prevented and the holding and engagement of the cylindrical portion of the supply reel gear or the take-up reel gear by the elastic frictional strip are secured to thereby preventing the idle rotation of the supply reel or the take-up reel with respect to the supply reel gear or the take-up reel gear. Therefore, the supply reel,or the take-up reel and the supply reel gear or the take-up reel gear are made rotatable integrally with each other thereby allowing the delivery and taking-up of the transfer tape to be performed securely. The invention will now be described by referring to an embodiment thereof and the ccompanying drawings. Fig.1 is an exploded front view of a coating tool according to one embodiment of the present invention; and Fig.2 is a cross-sectional view of a supply reel of the coating tool shown in Fig.1. In the drawings, reference numeral 1 designates a coating tool which comprises a main body 3 having an application head 2 projecting from an opening formed at the top thereof. The main body 3 houses therein a supply reel shaft 5, a take-up reel shaft 6 both of which are erected integrally from the inner wall surface 4 of the main body 3, a supply reel 10 having an engagement hole 13 and mounted on the supply reel shaft 5, a supply reel gear 7 having a cylindrical portion 12 and mounted on the same shaft 5 together with the supply reel 10, a take-up reel 11 mounted on the take-up reel shaft 6 and a take-up reel gear 8 mounted on the same shaft 6 together with the take-up reel 11. The mechanism of the tool is such that a transfer tape 9 wound about the supply reel 10 is delivered to the application head 2 and when the transfer tape 9 has passed over the application head 2, it is taken up around the take-up reel 13. In the above arrangement, according to the instant embodiment, the relationship between the supply reel 10 (or the take-up reel 11) and the supply reel gear 7 (or the take-up reel gear 8) is such that a number of elastic frictional strips 15 peripherally distributed is formed at a lower portion of the inner wall surface 14 of the engagement hole 13 of the supply reel 10 leaving a cylindrical gap 16 therebehind. A cylindrical portion 12 of the supply reel gear 7 is elastically held and engaged by the elastic frictional strips 15 and further, an annular rib 17 is formed extends from the cylindrical portion 12 of the supply reel gear 7 so as to fit in the cylindrical gap 16 so that the elastic frictional strips 15 are held sandwiched between the outer peripheral wall surface of the supply reel gear 7 and the annular rib 17. With the above-described structure, when the coating tool 1 is used in the usual manner, the user may carry the coating tool 1 by hand and slide it toward a certain direction whereupon an unused transfer tape 9' having a paste or a correcting paint adhered to the surface thereof is delivered from the supply reel 10 to the application head 2 and a transfer tape 9" which has become wasted or unavailable due to its passage over the application head 2 rotates integrally with a take-up reel gear 8 meshing with the supply reel gear 7 mounted on the supply reel shaft 5 together with supply reel 10. Thus, the waste transfer tape 9" is wound about the take-up reel 11 mounted on the take-up reel shaft 6 together with the take-up reel gear 8. Consequently, the delivery and taking-up of the transfer tape 9 can be performed smoothly and securely and further, even when the transfer tape draw-out speed becomes higher than its set speed due to the application of an excessively strong tensile force on the tape 9 and the supply reel 10 around which the unused transfer tape 9' is wound rotates to an excessive degree, the holding and engagement of the cylindrical portion 12 of the supply reel gear 7 by the elastic frictional strips 15 formed on the inner peripheral wall surface of the engagement hole 13 of the supply reel 10 are released so that the supply reel 10 rotates idly with respect to the supply reel gear 7 mounted on the same supply reel shaft 5. Further, the supply reel 10 delivers the unused transfer tape 9' from the supply reel 10 to the application head 2 while the tape-up reel gear 8 which engages the supply reel gear 7 mounted on the same shaft as the supply reel 10 stops rotating due to the idle-rotation of the supply reel 10 with respect to the supply reel gear 7 so that the take-up reel 11 mounted on the same shaft as the take-up reel gear 8 also stops rotating. As a result, no excessive degree of stress is applied on the transfer tape 9 thereby preventing the breakage or cutting of the transfer tape 9. Further, the elastic frictional strips 15 formed on the inner peripheral wall surface 14 of the engagement hole 13 of the supply reel 10 and adapted to hold the cylindrical portion 12 of the supply reel gear 7 so as to allow the supply reel 10 to become interlocked with the supply reel gear 7 can be made small in thickness or made of a soft material so as to have a sufficient degree of elasticity and therefore, even when the elastic frictional strip 15 tends to become thermally deformed by expanding outward during the storage and transportation of the coating tool in a high-temperature environment, since the annular rib 17 formed to surround the cylindrical portion 12 of the supply reel gear 7 is made to fit in a cylindrical gap 16 to be formed behind the elastic edging piece 15, the above-described type of deformation of the elastic frictional strip 15 is prevented and the holding of the cylindrical portion 12 of the supply reel gear 7 by the elastic frictional strip 15 is secured. Accordingly, the idle rotation of the supply reel 10 with respect to the supply reel gear 7 due to the deformation is prevented whereby the supply reel 10 and the supply reel gear 7 interlock with each other thereby enabling the delivery and taking-up of the transfer tape 9 to be performed smoothly and securely. As described above, the present invention has various advantages in that due to the fitting of the elastic frictional strip formed on the inner peripheral wall surface of the engagement hole of the supply reel between the annular rib formed to surround the cylindrical portion of the supply reel gear and the outer peripheral wall surface of the cylindrical portion of the supply reel gear, the deformation of the elastic frictional strips of the supply reel having the function of holding the cylindrical portion of the supply reel gear can be prevented securely thereby improving the durability of the parts such as the supply reel and the like forming the coating tool.

Claims: A coating tool, which comprises a main body (3) having an application head (2) projecting outwardly from an opening formed at the top end of the main body, a supply reel (10) accomodated in the main body for delivering to the application head an unused transfer tape having a paste or a correcting paint adhering thereto, said supply reel (10) having an engagement hole (13) and supported by a supply reel shaft (5), a supply reel gear (7) having a cylindrical portion (12) and mounted on the same shaft as that of said supply reel for common rotation therewith, a take-up reel (11) having an engagement hole and supported by a take-up reel shaft (6) so as to take up the transfer tape after use, a take-up reel gear (8) having a cylindrical portion and supported by the same shaft as that of said take-up reel for common rotation therewith, and a clutch mechanism for frictionally coupling one of said supply reel or take-up reel with respect to the supply reel gear (7) or take-up reel gear (8), respectively for allowing relative rotation therebetween, characterized in that said clutch mechanism comprises an annular rib (17) formed on said one reel gear (7,8) so as to surround said cylindrical portion (12) on the outer peripheral surface thereof, and a number of elastic frictional strips (15) formed on an end portion of the inner wall surface (14) of the engagement hole (13) of said one reel (10,11), said elastic frictional strips (15) fit between the annular rib (17) and the outer peripheral wall of said cylindrical portion of said one reel gear (7,8). The coating tool as claimed in Claim 1, wherein said annular rib (17) is formed on the take-up reel gear (8), and said elastic frictional strips (15) are formed on the take-up reel (10).

Inventors: MASUMOTO HIROAKI, MASUMOTO, HIROAKI
Applicants: TOMBOW PENCIL, TOMBOW PENCIL CO., LTD.
Application year: 2000
Main classification: B65H37
IPC codes: B65H37, B65H35, B43M11, B43L19