'Nov. 12, 1946._ ‘ w. R. TUCKER ' 2,410,909 UPWARD ACTING MOLDING PRESS Filed .April 28, 1944 54. 55 52 INVENTOR WARREN R-IUCKER' ’ ATTORN EYS 2,410,909 Patented Nov. 12, W46 .illJNlTED ‘STATES PATENT ()FFlCE , ' UPWARD ACTING MOLDING PRESS Warren’ R. Tucker, Dayton, ' Ohio, assignor to H-P-M Development Corporation, Wilmington, DeL, a corporation of Delaware , . Application April 28, 1944, Serial No. 533,105’ 4 Claims. - (01. 1s-T30) 1. 2 This invention relates to molding apparatus and, in particular, to a hydraulically actuated ?tted with a booster ram for the purpose of molding machine. the beginning of- a working cycle. A valve is pro ' effecting the rapid closing of the mold halves at ' I'n them'olding of plastics and similar sub vided which directs pressure ?uid to the main stances the': functions‘ to be accomplished by a clamping area'of the upward acting ram when machine include the clamping together of mold the mold halves are closed so as to maintain the halves or dies having cavities therein de?ning same clamped together under full clamping force. the shape of the workpiece to be formed and, the “A pressure responsive Valve is included in the injecting into the said cavity moldable material. hydraulic connection between the injection Usually the functions of clamping the molds 10 plunger and the main clamping plunger so that together and injecting the plastic therein are - when the clamping pressure has reached the de accomplished by separate units which may, if sired level the actuation of the injection plunger desired, be integrated by a timer or other suit automatically follows. Asecond ?uid connection able interlock so as to provide for a substantially is provided between the retraction areas of the automatic cycle. Also, the power units for sup 15 two plungers so that when the mold halves are plying power for‘clamping and injecting are usu ' opened, the injection plunger automatically re ally separate devices which may be mounted on tracts also. a common base or frame. Detailed description The primary object of the present invention is to provide a molding machine wherein the 20 Referring more particularly to the drawing, functions of mold clamping and plastic injection " the press according to this invention comprises are combined in a relatively simple structure. a cylinder ll! within which is reciprocably mount It‘ is. another object to provide a hydraulic cir ed the double acting plunger ||. Attached to the cuit for a machine of this type wherein the func end of the plunger H by any suitable means is a tion of injection is positively and automatically platen I2 which is adapted to'carry a mold or die sequenced relative to the function of clamping. ' half l3. The die half M which is adapted to co_ It ‘is still another object of vthis invention to operate with the die half I 3 is carried by the ?xed provide an improved hydraulic actuating system for a molding machine of this type. press bed l5. ' i _ ‘ ‘ The bed l5 is rigidly secured to, and positively These and other objects will become more'ap 30 spaced from the cylinder ill by means of the parent upon reference to-the following descrip- ‘ strain rods l6 and nuts H. tion and the attached drawing, which is a sec ‘The cylinder Ill and plunger || may be ?tted tional view of a molding press constructed ac with a booster ram, l8 so as to provide for the‘ cording to this invention and provided with an rapid closing oflthe mold halves. The booster improved hydraulic actuating system. ' ' 35 ram I8 is bored axially as at I9 to provide for > General arrangement ?uid communication with the bore 28 in the plunger ll‘. ' The plunger I |. is also bored as at ' The general arrangement of the press and sys 2| to receive theinjection plunger 22.‘ The in tempof this‘invention, as shown in the drawing, jection plunger 22 comprises a piston portion re comprises, preferably, an upward acting hydrau licram to which is attached a platen; The platen 40 ciprocable in the said bore 2i and a reduced - diameter portion 23 which extends through the is'adapted to carry one of the pair of mold'or die platen l2 and enters a cavity 24 within the mold half IS. The cavity 24 is for the purpose of re supported on a ?xed bed member. ‘ _ ceiving i the moldable‘ material which is to be The upward acting ram is bored to receive a 45 transferred or injected by the plunger 23 into reciprocating plunger, the function of which is to ' the cavities 25' inthe mold halves | 3 and I4. halves, the other of which is suitably stationarily ‘ transfer or inject plastic into the cavities Within the mold halves when the latter are closed to The upper endof the bore 2| is connected by a passage 26 with the smaller or retraction area of the plunger | |. The lowerend of the bore 2| ~~According to this invention, the pressure ?uid 50 is connected through a check valve 21 with the for ‘actuating the injection plunger is derived booster bore 20. The check valve 2‘! permits ?uid from~4the main area 1of the said upward acting flow from the bore 2| to the bore 20 but not vice~ gether. ' ' _ plunger,‘ thereby insuring-thatthemold halves are clamped together before the plastic is injected ' 'The'lower end 01‘ the bore 2| is likewise con therein, The main plunger may, if desired,_be 55 nected‘ a passage 28 with a valve 29 mounted 2,410,909 3 4 rod 53 and the valve member 52 upwardly to establish ?uid communication between the con duit 43 and the advancing side of the plunger ||. Preferably, the valve member 52 is shifted just in the platen l2. The valve 29 is connected by a passage 30 with the larger or advancing side of the plunger ||. The valve 29 is preferably an adjustable pressure responsive valve and is ef fective, upon the accomplishment of a predeter prior to the actual closing of the molds so that the upward speed of the plunger II is substan tially reduced thereby preventing any damage to mined pressure on the advancing area of the plunger H, to establish ?uid communication be the mold halves l3 and I4. tween the said advancing area of plunger | l and After the mold halves l3 and I4 have been the advancing area of the plunger 22. For the purpose of supplying ?uid pressure to, 10 engaged, the pressure on the advancing side of the plunger | I builds up until the desired clamp the press, a pump 48 is provided which delivers . ing force is developed by the said plunger. When pressure ?uid to a distributing valve 4|. The the required pressure has been developed, the valve 4| is connected by a conduit 42 with the retraction side of the vplunger H and, by a con duit 43 with the bore IQ of the booster plunger I8. A conduit 44 connects the valve 4| with a reservoir 45 from which ?uid is drawn by the pump 45 through a conduit 46. A conduit 41 which includes a check valve 48 interconnects the advancing area of the plunger 20 same is effective to shift the valve 29 to establish ?uid communication between the passages 28 and 35 thereby permitting pressure ?uid from the said advancing area to actuate the plunger 22 to accomplish the injection of the molding mate rial into the cavities 25. Upon the accomplishment of a dwell period, if desired, the plunger l | is retracted to open the || and'the reservoir 45. The valve 48 permits mold by shifting the valve 4| into position to free ?ow from the reservoir to the said advancing deliver pressure ?uid through the conduit 42 to area but prevents the ?ow of ?uid in the oppo the retraction area of the said plunger while site direction. The purpose of this connection, simultaneously exhausting the booster bore 20 which will become more apparent hereinafter, is and the advancing area of the plunger l|. to permit the ?lling with hydraulic ?uid of the When the plunger | | retracts, the plunger 22 is advancing chamber of the cylinder Hl during the also retracted by ?uid conducted thereto through initial rapid closing of the mold halves. the passage 26. As the plunger 22 retracts the A conduit 55 which includes a two-way valve 5| connects the advancing chamber of the cylin 30 ?uid on the advancing side thereof passes through the check valve 21 into the booster bore der H] with the conduit 43. The valve 5| in 26) from which it is exhausted as previously men cludes a valve member 52 adapted, selectively, to tioned- As the platen l2 approaches its fully establish or interrupt the continuity of the con retracted position the arm 59 engages the collar duit 5B. Attached to the valve member 52 is a 54 and moves the valve member 52 downwardly rod 53 which passes through lugs providedon into the position shown in the drawing, at which the bed and cylinder of the press. The rod 53 time the member 51 engages the collar 56 there has attached thereto a collar 54 which is engaged by retaining the valve member 52 in its down by a spring 55 which tends to urge the said collar, ward position until the platen again moves up together with the rod 53 and the valve member 52, upwardly. For the purpose of permitting the 40 wardly to actuate the said latch member. When the valve member 52 has been moved into posi advancing chamber of the cylinder H] to be ex tion to interrupt ?uid communication between hausted when the valve 5| is closed, the said the advancing chamber and the conduit 43, the valve is bypassed by a conduit including a check check valve 60 is effective to permit the exhaust valve 60 which permits ?uid ?ow from the said 45 of ?uid from the said advancing chamber. advancing chamber but not vice-Versa. It will be apparent that various modi?cations The rod 53 also has attached thereto a collar may be made in the structure and hydraulic cir 56 which is adapted to be engaged by a latch cuit of the device shown in the drawing without member 51 which is effective to maintain the rod in any way departing from the spirit of the in 53 and the valve member 52 in their down-ward position until the press platen l2 has reached a 50 vention. For example, the valve 5| could be operated by pressure established within the predetermined position during the advancing booster bore 26 without materially effecting the stroke thereof. An adjustable member such as operation of the press. Likewise, the particular the screw 58 is provided in the platen l2 .for the arrangement of valves and passages is only in purpose of engaging the latch 51 at the said pre determined position. The platen |2 likewise has 55 tended to be exemplary and does not represent the only possible arrangement. an arm 59 formed thereon which} engages the col , It will also be apparent that this invention can lar 54 andmoves the same, together with the rod 53 and the collar 56, downwardly until the latch member 51 engages the collar 56 when the platen _ reaches a predetermined retracted'position. be applied to a horizontally disposed molding machine as well as vertical machine without 60 materially eifecting the mode of operation of this invention. Also, it will be apparent that a press Operation In operation, a charge of plastic or material to be molded, is placed within the cavity 24. The ‘ valve 4| is then shifted to deliver ?uid into the 65 conduit 43 and thence through the bore l9 into the bore 20 while simultaneously exhausting the retraction side of the plunger || through the conduits 42 and 44; ~I ; - 7 ' constructed according to this invention is not necessarily limited in scope to the molding of plastics. cut could as well be used for die casting of metals and similar operations. Accordingly, it will be understood that I do not wish to be limited by the particular structure and arrangement shown in the drawing, but desire to comprehend such modi?cations thereof and sub With the valve 4| so shifted, the plunger ||' 70 stitution of equivalents‘ as come within the scope of the appended claims and the invention. moves upward rapidly until the screw 58 en Having thus fully described my invention, what gages the latch 51 rotating the latter clockwise I claim as. new and desire to secure by Letters so as to release the collar‘ 55 from engagement therewith. When the collar 56 is disengaged from ,, 1 Patent,'is: the latch 51, the spring 55 is effective to move the 75 1. In combination; a cylinder; a ?rst plunger 2,410,909 5 reciprocable in said cylinder; a bore in said ?rst plunger co-axial with said cylinder; a second plunger reciprocable in said bore; valve means hydraulically connected with said ?rst and said second plungers and operable in response to a predetermined pressure on said ?rst plunger for establishing ?uid communication between said plungers; and a ?uid source for supplying pres ~ 6 3. The combination in a molding press having a stationary platen and a movable platen; of a double acting ram connected with said movable platen for clamping mold halves together; cen tral axial bores extending into said ram from opposite ends thereof; a booster plunger extend ; ing into one of said bores; a double acting in jection plunger reciprocable in the other of said sure ?uid to said ?rst plunger for actuating the bores and extending through said movable plat same, a ?rst passage‘ in said ?rst plunger con 10 en, a fluid source to supply actuating ?uid to said necting one side of the same to one side of said booster plunger for rapidly closing said mold second plunger, a second passage in said ?rst halves and to one side of said clamping ram for plunger connecting the other side of the same to maintaining said mold clamped together said ram the other side of the second plunger, said valve having a first passage connecting one side of means being located in said second passage, and 15 the same to one side of said injection plunger; means connecting said passages to said ?uid a second passage in said ram connecting its other source. side to the other side of said injection plunger; 2. In a molding press; a double acting clamp pressure responsive means in said second pas ing ram; a central axial bore in said ram; a sage; a third passage extending through said double acting injection plunger reciprocably 20 booster plunger and said ram to said other side mounted in said bore; means continuously hy of said injection plunger; and a check valve in draulically connecting the retraction side of said said third passage, said source being connected plunger with the retraction side of said ram com to said passages. prising a ?rst passage in said ram connecting one 4. In a molding press having a stationary plat side of the same to one side of said injection 25 en for supporting a stationary mold half and a plunger; a second passage in said ram connect movable platen for supporting a movable mold ing the other side of the same to the other side ‘half; a double acting ram connected with said of said injection plunger; valve means in said platen for actuating the same in mold closing and second passage connected with the advancing opening movements; central axial bores extend side of said plunger and the advancing side 30 ing into said clamping ram from opposite ends of said ram and operable in response to a pre thereof; a double acting injection ram recipro determined pressure on the latter for estab cable in the one of said bores adjacent said plat lishing ?uid communication between said ad en, a stationary booster ram extending into the vancing sides; a third passage leading from said other of said bores; and means of supplying actu other side of said ram to said other side of said 35 ating .?uid sequentially to said rams for a com injection plunger and valve means therein oper plete molding cycle said last named means in able during the retraction stroke of said plunger cluding a ?rst passage in said ram connecting for bypassing said pressure responsive valve; and one side of the same to one side of said injec a source of pressure ?uid connected to each of tion plunger; a second passage in said ram con said passages and selectively operable for sup 40 necting its other side to the other side of said plying ?uid to the advancing or the retraction injection plunger, pressure responsive means in side of said clamping ram; whereby the supply said second passage, a third passage extending of pressure ?uid to the advancing side of said through said booster plunger and said ram to said clamping ram is effective to move the same into other side of said injection plunger; and a check clamping position and, subsequently, to actuate said injection plunger and the supply of pres sure ?uid to the retraction side of said clamping plunger is effective simultaneously to retract both said ram and said plunger. valve in said third passage and a source of ?uid connected to said passages. WARREN R. TUCKER.