US3762906A

US3762906A - Pressurized fluid ram acceleration system

Info

Publication number: US3762906A
Application number: US00278040A
Authority: US
Inventors: F Dahlman; R Mras
Original assignee: Corning Glass Works
Current assignee: Corning Glass Works
Priority date: 1972-08-04
Filing date: 1972-08-04
Publication date: 1973-10-02
Anticipated expiration: 1990-10-02
Also published as: DE2339168A1; NL7310770A; FR2194892A1; GB1416772A; JPS4953614A; IT992785B; BE803206A

Abstract

A system for rapid acceleration of a pressurized fluid actuated ram from a condition of rest to a condition of linear motion. A pressurized fluid intensifier is used in the system to, at times enable rapidly overcoming the static friction and inertia of a ram and its associated apparatus and rapidly accelerate the ram and apparatus to a desired velocity. The system is, for example, especially adaptable to operations, such as glass pressing operations, in which a ram is used to actuate a relatively massive pressing plunger to press form a relatively large article in or on a cooperative mold member.

Description

United States Patent Dahlman et a1. Oct. 2 1973 1, 1 PRESSURIZED FLUID RAM 2,706,891 4 1955 Greer 545 11A ACCELERATION SYSTEM 3,607,194 9/ 1971 Ayers 1 1 /160 3,634,060 1/1972 Dahlman 65/161 Inventors: Frederick A. Dahlman; Raymond J.

Mras both of Coming Primary Examiner--Martin P. Schwadron I73] Asslgnee: Corning Glass Works, Cornin N.Y. Asxistant Examiner-A. M. Zupcric g 1 Filed: g 1972 Attorney-Charles W. Gregg 7 1 pp N0 2 157]v ABSTRACT 1521 us. 01 65/160, 425/155, 60/545 HA, A M rapid i fluid /269 R actuated ram from a condmon of rest to a condmon of 1511 1111. c1. c031, Fl5h 7/011, B301) 1/32 11 T i zl f f 'fg 'f .g i" 1581 Field of Search 9l/6, 32; 60/469, e 1"' 60/486 54.5 HA 54.6 HA 100/269 R 269 B- tauc frlctlon and 1nert1a ofa ram and 1ts assoclated ap- 65/160 paratus and rapidly accelerate the ram and apparatus to a desired velocity. The system is, for example, espe- [56] Reierences Cited cially adaptable t operatiorls, such as glass pressing operatlons, 1n WhlCh a ram 15 used to actuate a rela- UNITED STATES PATENTS tively massive pressingplunger to press form a rela- 3,(;gt13,926 9/1972 Anldo 100/269 B tively large article in or on a cooperative mold member, 3,. ,5 l 8/1971 Ke ler 3,385,169

5/1968 Hale et a1.

8 Claims, 1 Drawing Figure V cm 0P w Plb 13| -19 510%, -s1 1 1 +PFI Plo PFV2 26 B IP Cyl "CY PV3 21- 4 g R 'PPR CHFM PRESSURIZ'ED PRESSURIZED e 111.110 FLUID FM 1 1 TO T0 2504000 s1 500 P51 PRESSURIZED PRESSURIZED FLUID FLUID SOURCE SOURCE PRESSURIZED FLUID RAM ACCELERATION SYSTEM BACKGROUND OF THE INVENTION In many glass pressing operations, for example, a relatively heavyweight crosshead is connected with the piston of a pressurized fluid cylinder or rarn which moves such crosshead and an associated forming plunger towards and away from each of a plurality of formingmolds which are sequentially moved to a pressing station at which the pressing apparatus including the crosshead, plunger and ram are located. It is readily apparent that the speed at which successive glass articles can be pressed by such apparatus depends some what on the speed at which said forming molds can be sequentially moved to said pressing station and this, of course, depends, somewhat on the speed at which said ram and its associated apparatus can perform a press forming operation.

When press-formed glass articles are of relatively large size, the crosshead and its supported plunger used in press forming such articles are substantially heavy and, therefore, have substantial static inertia at the end of the downward press forming stroke of such apparatus. Furthermore, there is often a substantial negative pressure or vacuum created or existing when the pressing plunger starts its upward stroke out of contact with a newly pressed article and such negative pressure or vacuum adds to the static inertia existing due to the weight alone of the pressing apparatus. It is accordingly an object of the present invention to provide a system, incorporating a pressurized fluid intensifier, for rapid acceleration of a ram and its associated apparatus from a condition of rest to a condition of linear motion.

It is another object of the present invention to provide a pressurized fluid ram acceleration system for glass pressing apparatus which will enable more rapid actuation of the ram actuated apparatus and thereby more frequent movement of each of a succession of molds to the pressing station at which the ram actuated or press forming apparatus is located. This will, of course, provide an economic advantage since more articles can be press formed per unit of time.

Other objects and characteristic features of the invention will become apparent as the description proceeds.

SUMMARY OF THE INVENTION A brief summary of the invention is believed to be adequately set forth in the foregoing abstract of the disclosure and, therefore, to prevent repetition orredundancy and for purposes of brevity, no further summary .of the invention is considered necessary nor will be given.

BRIEF DESCRIPTION OF THE DRAWINGS PREFERRED EMBODIMENT OF THE INVENTION Referring to the single drawing FIGURE in detail, thereis shown a pressurized fluid ram R comprising a cylinder CY embodying a bore B in which is disposed a piston P reciprocatively movable within such bore in the usual manner. One end of piston P is connected to a first end of the usual piston rod PR whose second end is connected to a combined crosshead and forming mold or plunger designated CHFM which is shown schematically only as a square or block for purposes of simplification of the drawing and because the details of such crosshead and forming mold are not a critical part of the invention. A cooperative mold member or forming mold FM is shown as carried on the upper surface or top ofa rotatable table T and is shown directly below the combined crosshead and forming mold CHFM. An article AR, which may for example be a large piece of flat glass which has just been press-formed between members CHFM and FM, is shown between the pressforming surfaces of such members.

A pressurized fluid intensifier PFI is provided and comprises a cylinder CYI embodying a bore Bl including a large diameter bore portion Bla and a substantially smaller bore portion Blb which connects with said portion B10 and is preferably concentric or coaxial with bore portion Bla. A core member or piston is embodied in bore B1 and includes a large piston portion Pla and a small piston portion Plb which fit snugly but slidably within said bore portions Bla and Blb, respectively. A compression spring SP surrounds small piston portion Plb with a first end of such spring bearing against the annular surface of large piston portion PM and the second end of the spring bearing against the inner surface of the wall defining the end of large bore portion Blu of bore Bl where it joins with small bore portion Blb of such bore. The operation of the pressurized fluid intensifier will be discussed hereinafter.

A fluid actuated three-position, five-way pressurized fluid flow control valve PFVI, a fluid actuated twoposition, two-way pressurized fluid flow control valve PFV2, a conventional single-direction fluid flow check valve CV1 and a fluid actuated or controlled fluid flow check valve CV2 are also provided. ValvePFVl is controlled by pressurized fluid pilot actuators PVl and PV2 to which pressurized fluid is selectively supplied as, for example, by the usual timing drum such as well known in the art but which is not shown in the drawings for purposes of simplification thereof. Springs SI and S2 normally maintain valve PFVll in a first or its neutral, center or normal position shown 'and, following an actuation of the valve by supplying pressurized fluid to pilot actuator PVl or PV2 and the subsequent termination of such supply of fluid, such springs return valve PFVl to its said neutral or normal position.

Valve PFV2 is controlled by a pressurized fluid pilot actuator PV3 to which pressurized fluid isalso selectively supplied as, for example, by the aforesaid timing drum. Valve PFV2 is normally biased or maintained by a compressible spring S3 in a first or normal position as shown in the drawing. When pressurized fluid is sup plied to pilot actuator PV3, such valve is actuated to its second position against the biasing force provided by spring S3 and, upon the subsequent termination of said supply of fluid, spring S3 again returns the valve to its normal position shown.

As previously mentioned, check valve CV1 is a conventional single-direction check valve of the type well known in the art and the purpose of such valve will be discussed hereinafter. However, as also previously mentioned, check valve CV2 is a pressurizedfluidactuated or controlled check valve which normally acts as a conventional single-direction check valve but is automatically actuated to a fully open or fluid flow condition and held in such condition when pressurized fluid is supplied to the valve over a control line or conduit hereinafter described and discussed.

Pilot actuator PV1 is connected over a conduit 11 to the previously mentioned timing drum which selectively supplies pressurized fluid to such actuator PV1 over said conduit 11 as hereinafter further discussed. Conduit 11 also connects to one end of a conduit 12 whose second end connects to check valve CV2 to selectively supply to such valve pressurized fluid for control of the valve as previously mentioned and as also further hereinafter discussed. Pilot actuator PV2 is connected over a conduit 13 to the previously mentioned timing drum which selectively supplies to such actuator pressurized fluid for actuation thereof as also discussed hereinafter. Conduit 13 also connects to one end ofa conduit 14 whose second end connects to pilot actuator PV3 of valve PFV2 for selective actuation of the latter valve in the manner previously mentioned. This will also be discussed in more detail hereinafter in operational examples of the invention.

Valve PFVl is connected over a conduit 15 to a source of pressurized fluid at a pressure, for example, between about 250 to 1,000 p.s.i. Valve PFVl is also connected over a conduit 16 to a source of pressurized fluid at a pressure, for example, of about 50 0 p.s.i. This latter source of pressure is also connected over a conduit 17 to the inlet port of previously mentioned check valve CV1. Valve PFVl is also connected over a conduit 18 to a fluid sink 8K2, and over a conduit 19 to a second end of bore B of cylinder CY of ram R for purpose of supplying pressurized fluid to such end of bore B and, thereby, to cylinder CY for actuation of piston P within the bore of cylinder CY and resultant corresponding actuation of piston rod PR and, actuation of crosshead and forming member CHFM in a direction to press form a desired article such as AR. This will be further mentioned hereinafter in the operational example of the invention.

Valve PFVl is also connected over a conduit 20 to the inlet port of check valve CV2, such conduit also connecting with the first end ofa conduit 21 whose second end connects to the low pressure or input port I? of large bore portion Bla of bore B1 of cylinder CYl of pressurized fluid intensifier PFl, that is, connects to said large portion Bla opposite the end of such bore portion which connects to small bore portion Blb of bore B1 of cylinder CYl. The outlet port of check valve CV2 connects over a conduit 23 to the first end of bore B of cylinder CY of ram R for supplying pressurized fluid to the second end of such bore and thereby actuate piston P, piston rod PR, and crosshead and forming member CHFM in a direction, out of contact with and away from a pressed formed article such as AR. This will be discussed further in the operational example which is to follow. The above-mentioned conduit 23 also connects to one end of a conduit 24 whose second end connects to flow control valve PFV2.

The outlet port ofcheck valve CV1 is connected over a conduit 26 to valve PFV2 and over a conduit to the high pressure or output port OP of small bore portion Blb of bore B1 of cylinder CY] of pressurized fluid intensifier PFl, that is, to the end of such small bore portion Blb which is opposite the end thereof which joins or connects with large bore portion Bla of bore B1 of cylinder CYl. The end of large bore portion Bla which joins with small bore portion Blb of bore B1 is connected over a conduit 27 to a suitable fluid sink SKI.

The apparatus of the system of the invention having been described in detail above, the previously mentioned operational examples will not be set forth for purposes of making the application complete.

Referring to the single drawing FIGURE in the case, the apparatus is shown in the position it occupies following or to which it is controlled during the press forming of an article such as AR between the combined crosshead and forming member CHFM and cooperative forming member FM. To actuate the apparatus to the positions shown, pressurized fluid is supplied by the previously mentioned timing drum to conduit 11 and thence to pilot actuator PV1, and to conduit 12 and thence to check valve CV2. Such pressurized fluid actuates check valve CV2 fully open and valve PFVl to its right hand position so that pressurized fluid from the aforesaid 250-l,000 p.s.i. fluid source flows from conduit 15 through valve PFVI to fluid conduit 19 and thence through such conduit to said second end of bore B of cylinder CY of ram R. This actuates piston P and piston rod PR in a direction to press form an article such as AR between said forming members as previously mentioned. At such time the fluid in said first end of cylinder CY is exhausted from such end of the cylinder through conduit 23 and check valve CV2 and thence through conduit 20 and valve PFVl to conduit 18 and fluid sink or reservoir SK2. This operation is conventional and no further discussion thereof is believed necessary for an understanding of the present invention.

Immediately following the press forming of an article such as AR as discussed above and a period of time for such article to become sufficiently cooled to become suitably set up, it is expedient to actuate member CHFM from out of contact with article AR as rapidly as possible so that table T can be rotated or moved to present another forming member such as FM to the press forming position for the press forming of another article such as AR at the earliest possible point in time and thereby attain the economical advantage which is possible in press forming an increased number of articles in a selected period of time. Accordingly, the previously mentioned timing drum is set so that, immediately following the press forming of an article such as AR, it operates, at the earliest possible point in time, to interrupt the control supply of pressurized fluid to pilot actuator PV1 and to immediately supply such pressurized fluid to pilot actuators PV2 and PV3. This causes valve PFVl to move in its left hand direction and valve PFV2 to move in its right hand direction. The pressurized fluid supplied to the second end of cylinder CY is interrupted and such end of the cylinder is immediately connected through valve PFVl to fluid sink 8K2. At the same time pressurized fluid from the previously mentioned 500 p.s.i. pressurized fluid source is supplied from conduit 16 through valve PFVl and

conduits

20 and 21 to bore portion Bla of bore B1 of cylinder CYl of pressurized fluid intensifier PFl and to the input side of check valve CV2 which is then acting as a conventional check valve since pressurized control fluid is no longer supplied over conduits 11 and 12 to such check valve CV2. The above-mentioned supply of pressurized control fluid to pilot actuator PV3 actuates such valve to in turn actuate valve PFV2 in the right hand direction to cause conduit 26 to be connected through valve PFVZ to conduit 24 and thence to conduit 23.

The 500 p.s.i. pressurized fluid supplied through conduit 20 to check valve CV2 flows through such valve to conduit 23 and thence to the first end of bore B of cylinder CY. The previously mentioned static inertia of combined crosshead and forming member CI-IFM and any vacuum or negative pressure existing between such member and the pressed article AR restrains, as previously mentioned, the actuation of piston P and piston rod PR of ram R at such time. However, the 500 p.s.i. pressure in the system and supplied over conduit 21 to bore portion Bla of cylinder CYl of pressurized fluid intensifier PSI urges the piston of the intensifier in a direction such that a substantially multiplied pressure is generated in bore portion Blb of cylinder CY]. This multiplied pressure is supplied through

conduits

25 and 26, and valve PFVZ, to conduit 24 and thence to conduit 23 and the first end of the bore B of cylinder CY. Such increased pressure is exerted against the end of piston P which is connected to piston rod PR and rapidly overcomes said static inertia and vacuum or nega' tive pressure and causes such piston to rapidly start and move member CHFM out of contact with article AR at a rate proportional to the force or pressure multiplication or intensification of intensifier PFI. Once such movement of said components has started and the high force or pressure required for said starting is no longer required, a high volume of the 500 p.s.i. pressure supplied to check valves CV1 and CV2 begins to flow through such check valves to conduit 23 and thence to the first end of bore B of cylinder CY of ram R to continue the movement of piston P, piston rod PR and the combined crosshead and forming member CHFM.

When said stroke or movement of piston P and its associated apparatus or members. is completed, the timing drum terminates the supply of control pressure to pilot actuators PV2 and PV3 and valves PFVl and PFVZ then return to their normal positions thereby also terminating the supply of pressure to the first end of bore B of cylinder CY and piston P comes to rest. When the timing drum initiates control pressure to pilot actuator PVl valve PFVl is actuated to the right and line I? is connected to line and line to fluid sink 8K2. Control pressure also opens check valve CV2 permitting pressurized fluid to flow from cylinder CY over line 23 and to said fluid sink 8K2. This generates a back pressure in line 20 until the piston comes to rest against article AR. At this time the pressure in

conduits

20 and 21 drops sufficiently that the force applied against large piston portion Pla of the piston in bore B1 is less than the combined force of compressed spring SP and the pressurized fluid force being supplied to bore portion Blb of bore B1 and against small piston portion Plb of the piston in bore B], said piston is returned to its normal position shown in the drawing and the apparatus is in readiness for press-forming of another article such as AR between a combined forming member such as CHFM and a succeeding forming member such as FM which has been moved by table T, for example, to the press-forming station.

Although there is herein shown and described only 5 one form of apparatus embodying the system of the m- 6 vention, it will be understood that various changes and modifications may be made therein within the purview of the appended claims without departing from the spirit and scope thereof.

We claim:

1. In combination with a pressurized fluid actuated ram including the usual pressurized fluid cylinder and an embodied piston and associated piston rod, a control system for rapid acceleration of the ram from a condition of rest to a condition of linear motion, such system comprising;

I. a pressurized fluid intensifier including a low pres sure input port and ahigh pressure output port;

II. a conventional single-direction fluid flow check valve having an inlet port connected to a first source of pressurized fluid and an outlet port connected to said output port of said pressurized fluid intensifier;

III. a controlled check valve normally operating as a fluid flow check valve for fluid flow therethrough in a direction only between an inlet port and an outlet port of such valve and actuable to a second condition for fluid flow therethrough in' a direction between said outlet and inlet ports of the valve, such inletport connected to said input port of said pressurized fluid intensifier;

IV. means including a two-position fluid flow control valve normally in a first condition in which flow of fluid therethrough is blocked and actuable toa second condition for connecting said output port of said intensifier with a first end of said cylinder and said outlet port of said controlled check valve;

V. means including a three-position fluid flow control valve normally in a first condition in which flow of fluid therethrough is blocked, such valve actuable to a second condition in which said inlet port of said controlled check valve is connected to a fluid sink and the second end of said cylinder is connected to a second source of pressurized fluid, and actuable to a third condition in which said inlet port of said controlled check valve is connected to said first source of pressurized fluid and said second end of said cylinder is connected to a fluid sink;

VI. means for at times simultaneously actuating said controlled check valve and said three-position valve to their said second conditions; and,

VII. means for at other times simultaneously actuat ing said two-position valve to its saidsecond condition and saidthree-position valve to itsrsaid third condition to provide said rapid acceleration of said ram.

2. A control system in accordance with claim 1 and in which said pressurized fluid intensifier comprises;

A. a pressurized fluid cylinder embodying a bore including coaxial and coextensive large and small bore portions connecting with said input and out put ports of the intensifier, respectively; and,

B. a piston including coaxial large and small piston portions disposed in said large and small bore portions respectively of said cylinder in arelatively snug but reciprocatively slidable relationship with each respective bore portion.

3. A control system in accordance with claim 1 and in which said ram is vertically disposed and said conditionof rest is a lowered press-forming condition of the ram.

4. A control system in accordance with claim 1 and in which said ram actuates a forming member for pressforming glass articles.

5. A control system in accordance with claim 2 and in which said ram is vertically disposed and said condition of rest is a lowered press-forming condition of the ram.

6. A control system in accordance with claim 2 and in which said ram actuates a forming member for pressforming glass articles.

7. In combination with a pressurized fluid actuated ram including the usual pressurized fluid cylinder and an embodied piston and associated piston rod, a control system for rapid acceleration of the ram from a condition of rest to a condition of linear motion, such system comprising;

l. a first pressurized fluid flow control valve having a first non-flow position and actuable to second and third positions for selectively controlling fluid flow therethrough;

II. a second pressurized fluid flow control valve having a first non-flow position and actuable to a second position for fluid flow therethrough;

III. a conventional single-direction fluid flow check valve having its inlet port connected with a first source of pressurized fluid;

IV. a controlled valve normally operating as a fluid flow check valve for fluid flow therethrough in only a single direction and actuable to a fully open condition for unchecked pressurized fluid flow there through in a direction opposite to said single direction;

V. a pressurized fluid intensifier including a low pressure input port and a high pressure output port with such output port connected with the outlet port of said conventional check valve;

VI. means including said first control valve, when actuated to its said second position, and said controlled check valve, when actuated, for connecting first and second end of said pressurized fluid cylinder with a fluid sink and a second source of pressurized fluid, respectively;

VII. means including said first control valve, when actuated to its said third position, for connecting said input port of said pressurized fluid intensifier with said first source of pressurized fluid and said second end of said pressurized fluid cylinder with a fluid sink, respectively; and

VIII. means including said second control valve,

when actuated to its said second position, for connecting said output port of said pressurized fluid intensifier with said first end of said pressurized fluid cylinder and said outlet port of said controlled check valve.

8. A control system in accordance with claim 7 and in which said ram is vertically disposed to actuate a forming member in a downward direction for pressforming of glass articles and said condition of rest is at the end of the downward press-forming stroke of the ram.

Claims

2. A control system in accordance with claim 1 and in which said pressurized fluid intensifier comprises; A. a pressurized fluid cylinder embodying a bore including coaxial and coextensive large and small bore portions connecting with said input and output ports of the intensifier, respectively; and, B. a piston including coaxial large and small piston portions disposed in said large and small bore portions respectively of said cylinder in a relatively snug but reciprocatively slidable relationship with each respective bore portion.
3. A control system in accordance with claim 1 and in which said ram is vertically disposed and said condition of rest is a lowered press-forming condition of the ram.
4. A control system in accordance with claim 1 and in which said ram actuates a forming member for press-forming glass articles.
5. A control system in accordance with claim 2 and in which said ram is vertically disposed and said condition of rest is a lowered press-forming condition of the ram.
6. A control system in accordance with claim 2 and in which said ram actuates a forming member for press-forming glass articles.
7. In combination with a pressurized fluid actuated ram including the usual pressurized fluid cylinder and an embodied piston and associated piston rod, a control system for rapid acceleration of the ram from a condition of rest to a condition of linear motion, such system comprising; I. a first pressurized fluid flow control valve having a first non-flow position and actuable to second and third positions for selectively controlling fluid flow therethrough; II. a second pressurized fluid flow control valve having a first non-flow position and actuable to a second position for fluid flow therethrough; III. a conventional single-direction fluid flow check valve having its inlet port connected with a first source of pressurized fluid; IV. a controlled valve normally operating as a fluid flow check valve for fluid flow therethrough in only a single direction and actuable to a fully open condition for unchecked pressurized fluid flow therethrough in a direction opposite to said single direction; V. a pressurized fluid intensifier including a low pressure input port and a high pressure output port with such output port connected with the outlet port of said conventional check valve; VI. means including said first control valve, when actuated to its said second position, and said controlled check valve, when actuated, for connecting first and second end of said pressurized fluid cylinder with a fluid sink and a second source of pressurized fluid, respectively; VII. means including said first control valve, when actuated to iTs said third position, for connecting said input port of said pressurized fluid intensifier with said first source of pressurized fluid and said second end of said pressurized fluid cylinder with a fluid sink, respectively; and VIII. means including said second control valve, when actuated to its said second position, for connecting said output port of said pressurized fluid intensifier with said first end of said pressurized fluid cylinder and said outlet port of said controlled check valve.
8. A control system in accordance with claim 7 and in which said ram is vertically disposed to actuate a forming member in a downward direction for press-forming of glass articles and said condition of rest is at the end of the downward press-forming stroke of the ram.