Plastics threaded fitting molding mechanism
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a plastics threaded fitting molding mechanism. 
     2. The Prior Art 
     It has been proposed in molding apparatus using conventional molding technique to make plastics threaded fittings in a single direction; however, it is desireable to make a three-way plastics threaded fitting for fluid flow. 
     SUMMARY OF THE INVENTION 
     The invention utilizes a plastics threaded fitting molding mechanism comprising three pushing rods with threadeded head portions to form female threads and three shafts co-axially disposed therein, to resolve the conventional problem of single direction plastics threaded fittings, and makes three-way plastics fittings by extruding molten plastics into a space generally defined by said rods and said shafts. 
     In utilizing the invention, there is provided plastics threaded fittings of molding mechanism a reduced manufacturing cost. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a frontal elevational view according to the present invention; 
     FIG. 2 shows the arrangement of three sprockets in transmission; 
     FIG. 3 is a partial view showing a vertical pushing assembly; 
     FIG. 4 is a partial view showing a horizontal pushing assembly; 
     FIG. 5 is shows horizontal pushing means and shafts; 
     FIG. 6 is shows the connection of horizontal shafts and a flange; 
     FIG. 7 is a perspective view showing a partial assembly of the invention; 
     FIG. 8 is shows the assembly of horizontal pushing means and a horizontal shaft; 
     FIG. 9 is a perspective view of a three-way plastics threaded fitting; 
     FIG. 10 is a frontal elevational view thereof; 
     FIG. 11 is a perspective view of FIG. 3; 
     FIG. 12 is a perspective view showing an exterior three-way plastics threaded fitting accordingly to another embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a plastics threaded fitting molding mechnism generally comprises transmission 100, vertical pushing assembly 200, vertical shaft assembly 300, horizontal pushing rod assembly 400, and horizontal shaft assembly 500. 
     The transmission 100 drives sprocket 10 and a pair of driven sprockets 20, driven by a motor (not shown) via chain 30 as shown in FIG. 2, so that said sprockets rotate in synchronism. Said driving sprocket is further connected to first gear 40 is engaged with second gear 501 on the end of shaft 50, and said shaft 50 has lower gear 502 mounted on the other end and is engaged with third gear 60, so that said third gear is driven simultaneously; meanwhile, said driven sprockets are co-axially engaged with main shaft 70 respectively, and thus, transmits power to first bevel gear 701 connected at a lower end of said main shaft. Said first bevel gear is further engaged with second bevel gear 80 to drive third gear 801 mounted adjacent to said second bevel gear, and then to fourth gear 90. Such that the power output from said motor is directed transversly for horizontal motion. 
     The vertical pushing rod assembly 200 has a plurality of rails 11 formed on the exterior surface of pushing rod 1 in the axial direction to be received by third gear 60 via a plurality of grooves 611, respectively (see FIGS. 3 and 11). Pushing rod 1 further has a threaded portion 20 at the upper end mounted with screw 2 of plate A, such that when said pushing rod is driven, plate A is to move simultaneously via said screw; and threaded portion 13 is formed at the lower end to receive molten plastic and to form the complement or female threaded portion of said plastics threaded fitting. 
     In the meantime, vertical shaft 300, which is disposed axially in the vertical pushing rod assembly 200, is forced to move vertically by an oil or air cylinder (not shown). 
     The horizontal pushing assembly 400 has a pair of horizontal pushing rods 3 provided with a plurality of rails 31 inserted into fourth gear 90 via grooves 901 (see FIG. 4) such that pushing rods 3 are driven in synchronism with fourth gear 90. 
     While one end of the pushing rods having threaded portion 32 to produce female threads on contacting the fitting inner surface, the other end with inner threaded portion 33 is engaged with shaft 4 and outer threaded portion 34 is engaged with flange B of framework C (see FIG. 1). 
     The horizontal plunger assembly 500 has a pair of horizontal shafts 4 with threaded portions 41 facing each other, disposed co-axially in the horizontal pushing rods 3 and threadedly engaged with each other at threaded portion 41 and inner threaded portion 33 (FIGS. 5 and 6). One end of said shafts 4 is engaged with key H, and secured to flange 5 is further mounted to flange B, such that the horizontal pushing rods are driven to rotate, and force horizontal shafts 4 threadedly moving each other. Moreover, the shafts are faster than pushing rods due to the threaded arrangement, so that shafts position will be slightly over the pushing rods at the end of the stroke. 
     It is further pointed out that, in other to reverse the operation, the motor of transmission 100 is rotated in reverse direction to drive the sprocket rotation reversely in synchronism. Similarly, shafts 4 are moving faster, and will be slightly disposed in the pushing rods. 
     In, as in operation, vertical pushing rod 1 is moving downward, and a pair of horizontal pushing rods 3 move each other forward, while, a pair of horizontal shaft performs in the same manner, such that molten plastic can be injected from cavity 91 formed on bottom plate 9 to form a three-way plastics threaded fitting G. Reversing the operation, and taking out the fitting, the operation can be operated continuously for fast and accurate production. 
     Accordingly, it is possible, using the invention mechanism, to make plastics threaded fittings with exterior threaded portions in the same manner. 
     Referring to FIG. 12, threaded portion 14 of an inner threaded portion is formed on the corresponding end of vertical pushing rod 1, and threaded portion 35 is formed on the horizontal pushing rods 3 to replace threaded portions 13 and 32 respectively, therefore, exterior threaded portions of the plastics threaded fitting k can be made accordingly. 
     And since the nature of making the fitting is to utilize the combination of pushing rods and shafts, the inner or outer diameters can be selected to fit various types of pipes.