LIQUID PRESSURE TRANSFER PRINTING METHOD FOR STEERING WHEEL RIM OF AUTOMOBILE

Abstract: A liquid pressure transfer printing method for a steering wheel rim of an automobile, using a transfer printing sheet having different patterns or brightness at the left and right sides thereof, is achieved by preparing a transfer printing sheet (32) for a front surface where patterns are arranged at all positions corresponding to transfer printing positions on the front surface of the core of the steering wheel rim and transfer printing sheets (32a) for part of a rear surface where patterns are independently arranged to correspond to positions of the patterns of the transfer printing sheet for the front surface, performing transfer printing on all transfer printing portions of the front surface of the core of the steering wheel rim by using the transfer printing sheet (32) while masking the rear surface of the core of the steering wheel rim, cleaning and masking the front surface after flipping the steering wheel rim, partially performing transfer printing on transfer printing portions of the rear surface by using the transfer printing sheets (32a).

Description: LIQUID PRESSURE TRANSFER PRINTING METHOD FOR STEERING WHEEL RIM OF AUTOMOBILE Technical Field The present invention relates to a method of performing transfer printing of a pattern to the core of a steering wheel πm for an automobile using a transfer printing sheet and more particularly to a liquid pressure transfer printing method for a steering wheel rim of an automobile by which the number of steps can be reduced so that the required cost and time are reduced a boundary created by performing transfer printing in more than one step is not noticeable, and the transfer-printed pattern can be smoothly connected when using a transfer printing sheet where the shapes of left and right patterns are greatly different or a difference in brightness is significant Background Art Conventional techniques of transfer printing to a steering wheel πm by using a transfer printing sheet are disclosed in Korean Patent Application Nos 98-17424, 98-17425 98-36990 98-36991 and 99-3368 filed by the present applicant Korean Patent Application No 98-17424 suggests a technique to solve problems such as extension and deformation of a printing pattern due to mismatch of a printing state by a conventional liquid pressure transfer printing method in which a film for transfer printing floats on water and an object is pressed from above According to this technique transfer printing can be selectively performed to a partial or entire surface by using a mask member such as masking tape or a rubber jig Thus a plurality of patterns or shapes can be transfer-printed to an object such as a ball or a circular frame to which it is difficult to transfer-print a pattern while maintaining a high degree of match Also Korean Patent Application Nos 98-1 7425 98-36990 and 98- 36991 disclose various liquid pressure transfer printing methods applied to a steering wheel πm of an automobile so that mass production is possible Also Korean Patent Application No 99-3368 discloses a technique for overcoming difficulty in a process requiring accuracy with respect to a combination boundary portion of a mask member in employing the above techniques so that faster and more accurate match of a pattern is possible According to this technique difficulties in maintaining the angle of an expected end portion of a masking tape to be 60° and performing a masking step after consecutive transfer printing while a distance of 0 1 - 0 2 mm is accurately maintained between the masking tape and the central line can be solved FIGS 1 through 5 show a steering wheel πm for an automobile and a liquid pressure transfer printing method for printing a pattern thereon according to the above-mentioned conventional techniques Referring to FIG 1 in a steering wheel πm arc-shaped portions a and b not including a portion 1 which is covered with leather are coated by a liquid pressure transfer printing method That is the liquid pressure transfer printing method is performed on the portions a and b FIG 3 shows the result of liquid pressure transfer printing applied to the portion a using a transfer printing sheet 2 having the same directivity at the left and right sides thereof as shown in FIG 2 Since FIG 3 is only for the purpose of explanation the size and shape of the transfer printing sheet are not drawn to correspond to the curvature of the portion a Since drawings showing transfer printing sheets which will be described later are also for the purpose of explanation, the state of curvature in these drawings also does not match the actual state of the portion a as shown FIG 1 Next by rotating the steering wheel rim by 180° liquid pressure transfer printing is performed on the remaining portion b FIG 5 shows an example of transfer printing using a transfer printing sheet 12 as shown in FIG 4 which is designed such that a pattern having directivity can be transfer-printed smoothly Thus various aesthetic and natural patterns can be presented by this method However in a process based on the above methods invented by the present applicant when a transfer printing sheet having a pattern to be presented is asymmetric and has directivity that is when a pattern or brightness is different at portions c and d as shown in FIGS 3 and 5 is to be transfer-printed there is a need to smoothly connect the pattern presented by the transfer printing sheet according to the difference in brightness of the pattern of the transfer printing sheet at the left and right sides and to improve natural pattern presentation so that the difference in brightness hardly occurs at the boundary portion during the second transfer printing after the first transfer printing is completed Also, as shown in FIG 5 since different patterns or different brightnesses are formed between the upper and lower surfaces of the steering wheel rim after transfer printing is performed, so that mismatch or an extreme difference in brightness occurs between the patterns the state of transfer printing is awkward and not natural To overcome this above problem the present applicant has suggested an improved liquid pressure transfer printing method in Korean Patent Application No 99-1 1606 FIGS 6A and 6B show a pair of complimentary transfer printing sheets 22 and 22a which are symmetrical with each other FIG 7 shows the state in which liquid pressure transfer printing is performed to both sides of the core of a steering wheel rim using the transfer printing sheets 22 and 22a The complimentary transfer printing sheets 22 and 22a are respectively transfer-printed to each of the surfaces of the steering wheel πm by rotating the πm by 180° between transfer printing steps As a result smooth transfer printing is performed so that a connection portion is not noticeable, as shown in FIG 7 However, when transfer printing is performed only to a particular portion of a steering wheel rim having a steering column attachment portion protruding one side as shown in FIG 1 , while transfer printing is easily performed on the side where no protruding portion is present transfer printing to the rear surface having the protrusion is difficult and transfer printing is poorly performed since the transfer printing sheet is obstructed by the protrusion Thus due to the structural difficulty, it is necessary to perform multi-step transfer printing for the rear surface of the steering wheel rim so that the protruding steering column attachment does not obstruct the transfer printing sheet Disclosure of the Invention To solve the above prob'ems, it is an object of the present invention to provide a liquid pressure transfer printing method for a steering wheel πm of an automobile which can prevent poor transfer printing resulting such as a difference in brightness or improper matching of patterns on the front and rear surfaces of a steering wheel πm so that a natural and aesthetic pattern or smooth brightness can be presented and an accurate and luxurious steering wheel rim can be manufactured Also, it is another object of the present invention to provide a liquid pressure transfer printing method for a steering wheel rim of an automobile which can minimize the number of repeated transfer printing steps required when a portion of a steering wheel rim to be printed on has an irregular shape so that the cost and time for work can be saved while improving productivity Accordingly, to achieve the above objects, there is provided a liquid pressure transfer printing method for a steering wheel πm of an automobile, using a transfer printing sheet having different patterns or brightness at the left and right sides thereof the method comprising the steps of preparing a transfer printing sheet for a front surface where patterns having a predetermined shape are arranged at all positions corresponding to transfer printing positions on the front surface of the core of the steering wheel rim by using computer graphics so that the patterns can be concurrently transfer-printed at the transfer printing positions, preparing transfer printing sheets for part of a rear surface where patterns of a predetermined shape are independently arranged to correspond to positions of the patterns of a predetermined shape of the transfer printing sheet for the front surface by using computer graphics so that transfer printing can be performed without interference on the rear surface of the core of the steering wheel πm where a steering column attachment portion protrudes, performing transfer printing on all transfer printing portions of the front surface of the core of the steering wheel rim by using the transfer printing sheet for the front surface while masking the rear surface of the core of the steering wheel rim cleaning and masking the front surface on which the first transfer printing has been performed after flipping the steering wheel rim partially performing transfer printing on transfer printing portions of the rear surface by using the transfer printing sheet for part of the rear surface It is preferred in the present invention that the transfer printing sheet for the front surface has a pattern of an arc shape all positions of which correspond to positions of the core of the steering wheel rim to which transfer printing is to be performed It is preferred in the present invention that the pattern formed on the transfer printing sheet for the front surface is complimentary about a center point Brief Description of the Drawings FIG 1 is a perspective view of a typical steering wheel πm FIG 2 is a view showing a typical transfer printing sheet used to perform transfer printing on the portions a and b of FIG 1 FIG 3 is a partially cut-away perspective view of a core of a steering wheel rim where liquid pressure transfer printing is performed using the transfer printing sheet of FIG 2 FIG 4 is a view showing another typical transfer printing sheet FIG 5 is a partially cut-away perspective view of a core of a steering wheel πm where liquid pressure transfer printing is performed using the transfer printing sheet of FIG 4 FIGS 6A and 6B are views showing a pair of complimentary transfer printing sheets suggested by the present applicant FIG 7 is a partially cut-away perspective view of a core of a steering wheel πm where liquid pressure transfer printing is performed using the transfer printing sheets of FIG 6A and 6B and FIGS 8A and 8B are views showing a pair of transfer printing sheets sequentially applied by the liquid pressure transfer printing method of a steering wheel πm for an automobile according to the present invention in which FIG 8A shows a transfer printing sheet for first front surface transfer printing which is designed such that transfer printing can be performed at once on all portions of the front surface of the steering wheel πm and FIG 8B shows a transfer printing sheet for second and third rear surface transfer printing which is designed such that transfer printing can be performed on part of the rear surface of the steering wheel πm where the steering column attachment portion protrudes Best mode for carrying out the Invention FIG 7 shows a state in which liquid pressure transfer printing is performed on both sides of a core of a steering wheel πm by using the transfer printing sheets 32 and 32a of FIGS 8A and 8B in which the portion a only is taken for the convenience of explanation from the circular steering wheel rim shown in FIG 1 FIGS 8A and 8B show an example of a transfer printing sheet 32 in which a star shape and a rectangular shape are formed at the left and right sides respectively, and the difference in brightness at the left and right sides is great In this case, while a portion e shown in FIG 7 is masked the other half portion f (the front surface of the steering wheel πm) is first transfer-printed Then, the star shape and the rectangular shape appear at the left and right sides in FIG 7 respectively That is since there is no protruding structure causing interference at the front surface of the steering wheel πm two arc shapes facing each other to be printed on both portions a and b are maintained and also a point symmetric shape can be designed as shown in FIG 8A When the front surface of the steering wheel πm is dipped in water in a state in which it is kept level with the surface of the water concurrent transfer printing can be performed on the entire surface in one step owing to the shape of the transfer printing sheet 32 After performing a cleaning step while the portion f on which transfer printing is performed is masked, by flipping the steering wheel πm over part of a surface corresponding to the portion e (the rear surface of the steering wheel πm) is secondarily transfer-printed by using the transfer printing sheet 32a of FIG 8B As a result the rectangular shape and star shape appear at the left and right sides in FiG 7 in which the steering wneel rim is flipped respectively Next the steering wheel πm is rotated by 1 80° so that transfer printing can be performed on the remaining portion of the steering wheel πm Then by dipping the remaining portion into water where another transfer printing sheet 32a shown in FIG 8B floats a third transfer printing is performed and all the steps are completed Consequently, the transfer printing sheet 32a for the portion e where the pattern is formed opposite to that of the transfer printing sheet 32 for the portion f is prepared and transfer printing is separately performed by using the transfer printing sheets 32 and 32a in the same manner Accordingly, the star shapes of the transfer printing sheets 32 and 32a are both located at the same side while the rectangular shapes are both located at the opposite side so that a natural and smooth connection of a pattern can be maintained and a product with no difference in brightness at the left and right sides can be obtained Also since it is possible to arrange patterns of the first transfer printing sheet 32 corresponding to portions of the steering wheel rim subject to transfer printing during the first step to perform transfer printing on the front surface of the steering wheel rim transfer printing on the front surface of the steering wheel πm is possible by a single transfer printing step Thus the process of transfer printing is simplified as the transfer printing to the front surface of the steering wheel πm is completed in one step working time can be remarkably reduced and productivity can be improved Industrial Applicability As described above when the patterns at the left and right sides of a core of a steering wheel rim on which transfer printing is performed are different in brightness and have directivity, transfer printing is performed first and second times by using transfer printing sheets having complimentary patterns Thus discontinuity due to mismatch of patterns or extreme difference in brightness can be removed and an aesthetic steering wheel rim can be manufactured Also in the case of an obstruction to transfer printing, by minimizing the repeated transfer printing steps, the cost and time for work is reduced so that productivity can be improved.

Claims: What is claimed is 1 A liquid pressure transfer printing method for a steering wheel πm of an automobile using a transfer printing sheet having different patterns or brightness at the left and right sides thereof the method comprising the steps of preparing a transfer printing sheet for a front surface where patterns having a predetermined shape are arranged at all positions corresponding to transfer printing positions on the front surface of the core of the steering wheel πm by using computer graphics so that the patterns can be concurrently transfer-printed at the transfer printing positions preparing transfer printing sheets for part of a rear surface where patterns of a predetermined shape are independently arranged to correspond to positions of the patterns of a predetermined shape of the transfer printing sheet for the front surface by using computer grapnics so that transfer printing can be performed without interference on the rear surface of the core of the steering wheel πm where a steering column attachment portion protrudes, performing transfer printing on all transfer printing portions of the front surface of the core of the steering wheel πm by using the transfer printing sheet for the front surface while masking the rear surface of the core of the steering wheel rim cleaning and masking the front surface on which the first transfer printing has been performed after flipping the steering wheel πm partially performing transfer printing on transfer printing portions of the rear surface by using the transfer printing sheet for part of the rear surface 2 The method as claimed in claim 1 wherein the transfer printing sheet for the front surface has a pattern of an arc shape all positions of which correspond to positions of the core of the steering wheel πm to which transfer printing is to be performed 3 The method as claimed in claim 2 wherein the pattern formed on the transfer printing sheet for the front surface is complimentary about a center point 4 The method as claimed in claim 1 wherein the transfer printing sheet for the rear surface has a pattern having an arc shape the design on which is symmetric for a point with respect to the design on the transfer printing sheet for the front surface

Inventors: CHO YOUN-SOO, CHO, YOUN-SOO
Applicants: CHO YOUN SOO, CHO, YOUN-SOO
Application year: 2001
Main classification: B62D1
IPC codes: B41M3, B44C1, B62D1