Cantilever type screen-printing machine with double platform

The present invention discloses a cantilever type screen-printing machine with double platforms that possess a gear reducer motor with a hollow shaft to rotate a screw of a threaded screw unit and further drive a threaded rod to move upward and downward without rotation inside the hollow shaft thus make a transverse sliding assembly move vertically and synchronously with the threaded rod. Moreover, by a rectangular frame and two sets of horizontal micro adjustable chase clamping mechanism transversely fixed on the rectangular frame, the relative position between the chase and the print materials is adjusted directly. The upper and the lower platforms are driven and powered by two gear reducer motors and a homocentric coaxial-type driving mechanism respectively. By the simplified driving mechanism, the printing efficiency and productivity are enhanced.

BACKGROUND OF THE INVENTION

The present invention relates to a cantilever type screen-printing machine with double platforms, more particularly to a screen-printing machine which possess a gear reducer motor with a hollow shaft to rotate a screw of a threaded screw unit and further drive a threaded rod to move upward and downward without rotation inside the hollow shaft thus make a transverse sliding assembly move vertically and synchronously with the threaded rod. Moreover, by a rectangular frame and two sets of horizontal micro adjustable chase clamping mechanism transversely fixed on the rectangular frame, the relative position between the chase and the print materials is adjusted directly. The upper and the lower platforms are driven and powered by two gear reducer motors and a homocentric coaxial-type driving mechanism respectively. By the simplified driving mechanism, the printing efficiency and productivity are enhanced.

According to description of prior arts, double-platform screen-printing machine already exists in the categories of cantilever type screen-printing. Each platform has its own gear mechanism so that both platforms can print and process top and bottom print matters reciprocally. Furthermore, double platforms has the function of printing and managing print materials simultaneously so as to reduce the idle time of changing printing materials. Therefore concerning printing speed and productivity, it is far more better than the printing machine with a single platform, but the designation can not be too complicated in order not to increase the machine cost and space occupation. Moreover, a conventional cantilever type double-platform screen-printing machine is less efficient than a single-platform screen-printing machine in precision control of the elevating mechanism of transverse sliding assembly's vertical shifting, or the relative position (such as x, y axis pair position or z axis's horizontal degree) between the chase and the printing materials.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide a cantilever type screen-printing machine with double platforms, powered by a gear reducer motor with hollow shaft which rotates the screw of a precision threaded screw unit and drives the threaded rod to move upward and downward vertically without rotation in the hollow shaft. Then the drive transverse sliding assembly is driven synchronously with the vertical movement of the threaded rod and thus the effect of digitalized, speedy, and precise control on multiple vertical movements of the transverse sliding assembly is achieved.

It is a further object of the present invention to provide a cantilever type of double platform screen-printing machine, between the right and left cantilever arms of transverse sliding mechanism fixes a horizontal micro adjustable chase clamping mechanism which is combined from a rectangular frame with two cantilever arms, furthermore two sets of chase clamping device fix transversely on top of rectangular frame to process horizontal adjustment at right and left hand side so that the relative position (Z axis horizontal degree) between chase and print mateials can process horizontal micro adjustment.

It is a further object of the present invention to provide a cantilever type screen-printing machine with double platforms by using the power supply of two gear reducer motor, and a gear mechanism formed from the unitary coaxial inner and outer shaft to drive the upper and the lower platform to progress the reciprocal activity or single upper platform forward and backward activity of double platforms so as to minimize the gear mechanism and designed space and maximize the printing speed and the efficiency of printing productivity.

It is a further object of the present invention to provide a cantilever type screen-printing machine with double platforms, further set up X axis and Y axis platform micro adjuster on the upper an the lower platforms to make print materials on different platform matching related chase clamping by chase clamping mechanism has the function of unitary X axis or Y axis micro adjustment, or dual directions micro adjustment of X-Y axis, or ⊖ degree of circumvention adjustment for the upper and the lower platforms.

It is a further object of the present invention to provide a cantilever type screen-printing machine with double platforms, further arrange platform aspirator on the upper and the lower platforms to suck the print materials on the correct position and to avoid shifting in progress of printing.

It is a further object of the present invention to provide a cantilever type of double platform screen-printing machine, on the chase bottom arrange a scrap ink scraper device on the back edge side of the upper platform, then after chase elevating with chase clamping mechanism simutaneously the scrap ink scraper device rise scraper groove to align against the chase bottom and clear the scrap ink during the period of the upper platform perform the printing process, furthermore the scrape groove has the functionality of microadjust to precisely control the alignment of scrape groove and the surface of chase bottom.

It is a further object of the present invention to provide a cantilever type of double platform screen-printing machine, magnetic buffer is set up right behind left and right runner track respectively which combines from magnetic iron and buffer, and arrange magnetic iron and buffer opposite to each end of right and left hand side of the upper and the lower platforms respectively, so that the rapid movement of the upper and the lower platforms can be halted on printing stop position by the assistance of magnetic buffer disperse quick stop momentum by sucking, and therefore efficiently control the instant stop quake. By the way magnetic iron stop platforms use its suction force to make sure that platforms stop at the right position for each printing movement.

DETAILED DESCRIPTION OF THE PREFFERED EMBODIMENT

Refer to Fig. a cantilever type screen-printing machine with double platforms is mainly composed of a base10, an elevating mechanism20, a transverse sliding assembly30, a chase clamping mechanism40, a main printing mechanism50, and a double-platform mechanism60. The transverse sliding assembly30is vertically lifted by the elevating mechanism20. And on right and left cantilever arms of the transverse sliding assembly30connected the chase clamping mechanism40which vertically moves with the transverse sliding assembly30synchronously. The main printing mechanism50that slides rightward and leftward to process printing is fitted on the transverse sliding assembly30.

Under the main printing mechanism50is a double-platform mechanism60having an upper platform and a lower platform which are loaded with print materials and slides under the main printing mechanism50respectively for processing printing.

With reference ofFIG. 2, the elevating mechanism20includes right and left aluminum rectangular columns200, each with a set of linear sliding rails201which is connected with a connection board204on inner side respectively while the connection board204is further connected with the transverse sliding assembly30. A gear reducer motor202is fixed under the two aluminum rectangular columns as power supply resource for rotating a screw205of a precision threaded screw unit, thus driving a corresponding threaded rod203to move upward an downward without rotation inside a hollow shaft. Moreover, the threaded rod203is connected with the connection board204by a top block206at the upper end thereof so as to drive the transverse sliding assembly30synchronously with the upward and downward movement of the threaded rod203. Furthermore, a precision coder fixed on the gear reducer motor202is used to record the detail movement (not shown in figure) so as to make the vertical movement of the transverse sliding assembly30under digital control.

Refer toFIG. 3, the transverse sliding assembly30includes a aluminum extrusion transverse column300with a seal block301on right and left ends, and a linear slide rails302on inner side thereof to make the main printing mechanism50slide back and forth along the linear slide rails302. An active belt pulley303and a passive belt pulley304are arranged on both ends of the inner side of the transverse column300while the active belt pulley303is driven by a motor305so as to make the main printing mechanism50slide rightward and leftward by the belt.

Referring toFIG. 4–4A, the chase clamping mechanism40having a rectangular frame400and two sets of chase clamps40a. Right and left sides of the rectangular frame400are fastened under right and left cantilever arms401,402respectively. By a shifting cylinder403on cantilever arms402–401respectively, the chase is moved vertically. Furthermore, the two sets of chase clamping device40aare fixed transversely on top of the rectangular frame400by fastening units415at front and rear ends thereof. The fastening units415can be bolts device shown onFIG. 4–4a, or other locking parts (not shown in figure), such as pneumatic cylinder (apply in large screen-printing machine or screen-printing machine with various chase sizes) and screws. The chase clamping device40ais composed by a fixed lever404, a holding plate405, and a plurality of clamping pneumatic cylinder406for holding the rectangular frame400(on which mounts a chase). For mounting the screen on the screen-printing machine, firstly loosen the front and back fastening unit415of the chase clamping device40a, then adjust the position and the distance of the two sets of chase clamping device40aon rectangular frame400, and clamp the chase by the clamping pneumatic cylinder406before aligning the chase and printed papers on the lower platform. When finishing alignment, the two sets of chase clamping device40aare connected on the rectangular frame400firmly by the fastening units415. While the chase clamping device40afeatures on that: on both ends of the fixed lever404where connected with the rectangular frame400, a vertical micro adjuster41ais installed for micro-adjusting the span between the fixed lever404and the rectangular frame400after the chase being fixed. Thus the chase clamping device40aand the clamped chase thereof can adjust their vertical position relating to the rectangular frame400, keep the effect of steady distance between the chase and the platform and attain the printing quality requirement of precise printing thickness. A vertical micro adjuster41ais set up in front and back end of the fixed lever404respectively and having a forward piece407and a backward piece408, both attached with a washer plate409which includes a plurality of assembling screws413and one fastening screw412. By a plurality of anti-loose assembling nuts414and an anti-loose fastening nut416, the washer plate409is fastened on the fixed lever404. Furthermore, holes on the fixed lever404for assembling screws413and fastening screw412are vertical long narrow hole so that the forward and the backward piece407–408can vertically adjust in proper position.

Fastening units415are fitted on the outer side of the forward and the backward piece407–408for fixing the chase clamping device40aon the rectangular frame400. Moreover, a horizontal adjusting bolt411and a washer410are arranged in the inner surface side of the forward and the backward piece407–408and are fixed on top of the fixed lever404through a hole in the forward and the backward piece407–408. In addition, the washer410screwed on the horizontal adjusting bolt411to cover on the hole prevents the screwed horizontal adjusting bolt411from loosening off. The horizontal adjusting bolt411(can be hexagonal bolt) can not be shifted thus causes the fixed lever404to shift vertically and attain the vertical micro-adjustment function on the distance between the fixed lever404and the rectangular frame400so that make the micro-adjust effect between the chase and printing matters.

The assembling screws413and the anti-loose assembling nuts414can connected closely, but can be shifted without hamper the vertical movement of the fixed lever404while adjusting the horizontal adjusting bolt411.

Referring to FIGS.5–6–6A–6B–6C, the double-platform mechanism60mainly includes a right and a left runner tracks601–602, an upper and a lower platforms604–608, a homocentric coaxial shaft61, and two gear reducer motors620wherein the right and the left runner tracks601–602fixed on the right and the left sides of the base10where a supporting sliding track626and a gear sliding belt627with different altitude are accommodated therein while the right and the left sides of the upper and the lower platforms604–608are connected with the gear sliding belts627by the sliding connection bars605–606and slide forward and backward along the supporting sliding track626. Moreover, the homocentric coaxial shaft61having an inner shaft611fitted in an outer shaft610is arranged transversely on the rear portion of the right and the left runner track601–602. Outer and inner bearings613–614are fixed at both ends of the outer shaft610and the inner shaft611for supporting. Furthermore, on two sides of the outer shaft610and far beyond the inner shaft611, two passive belt pulleys617–618powered and driven by the respective gear reducer motor620are set there respectively. The outer shaft610and the inner shaft611rotate respectively. In addition, the two gear reducer motors620are fixed with a coder622respectively in order to control the inner and the outer shafts610–611and attain the effect of PLC control accordingly. Thereafter, the gear reducer motor620could be replaced by a normal motor, a stepping motor, a servo motor, etc. in combination with other control mechanisms so as to have the same function as the gear reducer motor620. And the above-mentioned belt pulleys such as active belt pulleys621, passive belt pulleys617–618, can also be replaced by other equivalent products such as geared belt pulleys, general belt pulleys or chain pulleys.

At run, the double-platform mechanism60uses the two gear reducer motors620to drive outer and inner shafts610–611respectively so that the inner and the outer shafts can rotate in various modes such as both shafts runs simultaneously in the reverse rotate direction, or in the same rotate direction, or different rotate speed for the inner and outer shafts respectively, or only one shaft rotates, etc. Thus makes the upper and the lower platforms604–608shift back and forth reciprocally, or simultaneously, or single platform shifting, etc. so as to apply the two platforms604–608for different requirements by adjusting different shifting types. For example, while in large volume printing process, the two platforms604–608are adjusted into reciprocal shift printing type so as to print at the same time and spend no idle time for preparing printing materials thus increase the sliding speed and print productivity. If only a small amount of printing is processing, an upper platform604is used for shifting and printing.

The double-platform mechanism60further having a magnetic buffer63, an X axis micro adjuster65, a Y axis platform micro adjuster66, an ink scraper67, or a platform aspirator68so as to achieve more accurate printing effect. Or optionally add a safety lever64for safety sake.

Referring to FIGS.1–5–6, the magnetic buffer63is set on the rear end of the right and the left runner tracks601–602. The magnetic buffer63includes a fixed block631with a magnetic iron632and an oil hydraulic buffer633thereon while the positions of the magnetic iron632and the oil hydraulic buffer633correspond to the left and right sides of the upper and the lower platforms604–608respectively. Thus the rapid movement of the upper and the lower platforms604–608can be halted when approaching the stop position of the printing by the assistance of the oil hydraulic buffer633taking in momentum of quick stop and efficient control the shaking phenomenon of instant stop as well as the function of the magnetic iron632for assuring that the platforms604–608can precisely go back and stop at the right position for each movement. The type of oil hydraulic buffer633can be changed into a pneumatic cylinder buffer, or other devices with same function as shaking absorbing effect. In addition, the magnetic buffer63can fix either at the rear side as shown by the figure, or at the front end for material feeding.

Referring to FIGS.7–7A–7B, the X axis micro adjuster65and the two Y axis micro adjuster66are fixed under the upper and the lower platforms604–608, between the platform surface604(608) and a bottom plate603(607), wherein the X axis micro adjuster65arranged in the center of the front end of the platform604(608) is primary combined from a knob651, a bevel gear set (right angle gear set)650, and a gear block656which is mounted on the bottom plate603(607). When process micro adjustment, roll the knob651to drive the bevel wheel653of the bevel gear set650through the knob fixed part652. Then the passive bevel wheel654of X axis is rotated and thus driving the gear block656moving in X axis direction (rightward and leftward) by the threaded rod and a block fixed part655so as to have the X axial relative shift between the platform604(608) and the bottom plate603(607) as well as attain the effect of X axial adjustment. The two Y axis platform micro adjusters66are fitted on left and right sides of the X axis micro adjuster65and each having a knob651, a knob fixed part652, a micro adjust threaded bar662, a block fixed device663, and a gear block656mounted on the bottom plate603(607). When process micro adjustment, roll the knob651to drive the micro adjust threaded bar662through the knob fixed part652and then drive the block fixed device663and the gear block656to progress in Y axis direction (forward and backward) thus have Y-axial relative shift between the platform604(608) and he bottom plate603(607) and achieve the effect of Y axial adjustment. By use of the dual adjustment of the X axis micro adjuster65in the platform center and two Y axis platform micro adjuster66on both sides of the platform, the results of unitary X axis or Y axis micro adjustment, or dual directions micro adjustment of X-Y axis(two points or multiple points of X-Y axis on a 90° plane angle), or ⊖ degree of circumvention adjustment are achieved.

Refer to FIGS.5–6–6B–6C, After finished printing process, the chase left by the cantilever arms40, then the ink scraper67rise a scraper groove678to the chase bottom and scrape away redundant ink on the chase bottom. The ink scraper67are fixed on right and left sides of the rear portion of the upper platform604by the two cylinder fixed plates671, each with a cylinder673. By a fixed clench bar670, the cylinder673is connected with the gear block672. Thus the two gear blocks672are stretched by two cylinders673to make the fixed clench bar670stretched up and down by the control of cylinder673. In addition, the scrape groove678screwed firmly by two manual bolts675on both ends of the fixed clench bar670can be assembled and disassembled conveniently for cleaning the ink therein. Moreover, a micro adjust bolt674is set up between the fixed clench bar670and the two gear blocks672at both end respectively for vertical adjustment of the fixed clench bar670as well as precise control of the contact between the scrape groove678and the chase bottom. Furthermore, the cylinder673can be other type of vertical adjustment mechanism, whatever can perform the scrape groove's action will be accepted.

Referring toFIG. 6, the platform aspirator68locates at the platform604–608to attach the print materials in right position and avoid print materials shifting in printing process. The platform aspirators68are arranged under double platforms respectively and each possesses a connection joint641with a suction hose640which is connected to a suction device (not shown) with the other connection joint642. The suction hose640of the upper platform604is fixed at the middle side of the right runner track601, while the suction hose640of the lower platform608is fixed thereunder so that the two suction devices68will not interfere with each other when the two platforms run reciprocally, that is, the suction devices could suck at the same time, or the one sucks while the other blows at a time.

Referring to FIGS.1–5–6, within the sliding range and in front of the two platforms604–608are fixed with two safety lever64which consists of a right lever and a left lever. Once one of the levers64is swing open as shown inFIG. 5, power will be off immediately to avoid operators being hit by the running platform within the sliding range, and therefore increase the safety of operation environment.