GB1600733A - Coining presses - Google Patents

Coining presses Download PDF

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Publication number
GB1600733A
GB1600733A GB913877A GB913877A GB1600733A GB 1600733 A GB1600733 A GB 1600733A GB 913877 A GB913877 A GB 913877A GB 913877 A GB913877 A GB 913877A GB 1600733 A GB1600733 A GB 1600733A
Authority
GB
United Kingdom
Prior art keywords
piston
cylinder
main
fluid
pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB913877A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Midgley A C
Original Assignee
Midgley A C
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Midgley A C filed Critical Midgley A C
Priority to GB913877A priority Critical patent/GB1600733A/en
Publication of GB1600733A publication Critical patent/GB1600733A/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/16—Control arrangements for fluid-driven presses
    • B30B15/161—Control arrangements for fluid-driven presses controlling the ram speed and ram pressure, e.g. fast approach speed at low pressure, low pressing speed at high pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/028—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force
    • F15B11/032—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force by means of fluid-pressure converters
    • F15B11/0325—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force by means of fluid-pressure converters the fluid-pressure converter increasing the working force after an approach stroke
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/21—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge
    • F15B2211/214—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge the pressure sources being hydrotransformers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7051—Linear output members
    • F15B2211/7053—Double-acting output members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/775—Combined control, e.g. control of speed and force for providing a high speed approach stroke with low force followed by a low speed working stroke with high force, e.g. for a hydraulic press

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)

Description

(54) IMPROVEMENTS IN AND RELATING TO COINING PRESSES (71) I, ALLAN CLOUGH MIDGLEY, a British Subject, of "Fairfield", Hall Drive, Bramhope, Leeds Us 16 9JF, Yorkshire, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to coining presses comprising pressure displacement means.
In the operation of a coining press, only a short working stroke is necessary and such a stroke can readily be provided with great pressure by the use of a hydraulic intensifier piston. However, it is frequently also necessary to displace the ram of the press a relatively considerable distance in order to close the press after the insertion therein of the object to be pressed before the pressing stroke proper is applied. It is, of course, possible to use separate means for effecting the low-pressure displacement and the shortstroke pressing load, but the need for switching from one means to another complicates the apparatus and it is an object of the present invention to satisfy these requirements by a simplified apparatus.
According to the invention there is provided a coining press having pressure displacement means comprising a main cylinder, a main piston in the main cylinder and displaceable relatively thereto, a secondary cylinder adjacent to said main cylinder and connectable to a source of pressure fluid, an elongate intensifier piston, of which the head is of diameter greater than that of the shank, displaceable within the secondary cylinder under pressure of fluid from said source on said head whereby said shank, which extends from the secondary cylinder into the main cylinder, effects a relative-displacement between the main piston and the main cylinder, means defining a passage for allowing pressure fluid to flow from the said source into the main cylinder to displace the main piston without displacement of the intensifier piston from a predetermined position, and means for closing said passage on such displacement of the intensifier piston.
Preferably the secondary cylinder is vented to atmosphere behind the head of the intensifier piston.
An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings of which the single figure shows in cross section the movable ram of a coining press.
In the figure, the movable lower ram of a coining press of which the press head is not shown, takes the form of a main piston 1 displaceable vertically within a main cylinder 2 supported by conventional bearings and seats 3.
A secondary cylinder 4 is mounted below the main cylinder 2 and an intensifier piston 5 is located in the secondary cylinder and comprises a head 6 of diameter corresponding to that of the cylinder 4 and a shank 7 of smaller diameter which extends through a bore of appropriate diameter into the main cylinder 2.
The secondary cylinder 4 is provided with a pressure fluid supply port 8 by which it can be connected to a source of pressure fluid. An axial bore 9 in the intensifier piston 5 provides a passage from the large diameter face 10 to the small diameter face 11 of the intensifier piston.
Within the bore 9 is a ball valve 12 comprising a ball 13 adapted to close the passage when pressed against seating 14.
However, when the intensifier piston 5 is in the lowermost or start position as shown in the Figures, the ball 13 is displaced from its seating 14 by means of peg 15 which extends upwardly from the base of the cylinder 4.
Thus, in operation, with the port 8 connected to a source of pressure fluid, pressure fluid enters into the end 16 of the cylinder 4 and enters the bore 9 in the intensifier piston 5. Bypassing the ball 13 in the ball valve 12, the fluid passes along the bore until it reaches the main cylinder 2. Provided the pressure of the fluid is sufficient to overcome the mass of the main cylinder 1 and the friction of the piston against the walls of the cylinder, the piston 1 will be raised in its cylinder.
Although the pressure of fluid exerted on the faces 10 and 11 of the intensifier piston are equal, and the area of the face 10 is greater than that of the face 11, the intensifier piston 5 will not move from its start position if the fluid pressure is so low that the pressure difference between the ends of the intensifier piston is not sufficient to overcome the friction of the intensifier piston bearings and seals 17 and the mass of the intensifier piston.
However, when the rising main piston I closes upon the press head or upon the article to be pressed against the press head, and the pressure of fluid supplied from the source increases, the absolute value of the difference in the forces exerted on the upper face 11 and the lower face 10 of the intensifier piston increases to the point where it exceeds the aforementioned friction and mass, and the intensifier piston begins to rise in the cylinder 4. As the ball valve 12 clears the peg 15, the ball 13 is allowed to fall against the seating 14 and the passage defined by the bore 9 is closed, with fluid entrapped within the main cylinder 2. As the head 6 of the intensifier piston 5 rises in the cylinder 4, the main piston 1 rises in the main cylinder 2 with a reduced stroke and an increased force depending on the ratio of the areas of the surfaces 10 and 11 of the intensifier piston 5.
The excessive pressure in the main cylinder 2 compared with the lower cylinder 4 ensures that the ball 13 is kept firmly against its seating 14. During the elevation of the intensifier piston in the secondary cylinder 4, air in the annular zone above the piston head 6 is vented through ports 18.
When the pressing operation has been completed, using a pressing force derived from the pressure of the fluid multiplied by the ratio of the areas of the faces 10 and 11 of the intensifier piston, and it is desired to release the press, port 8 is disconnected from the fluid supply and is vented, whereupon the main and intensifier pistons lower in their respective cylinders under gravity. In other embodiments of the invention, not illustrated, the annular space above the head of the intensifier piston is occupied by pressure fluid from an alternative source, or a compression spring, more positively to sequence the operation and to facilitate the downward movement of the intensifier piston.As the main piston 1 withdraws from the press head, the pressure of fluid in the main cylinder 2 will diminish and the ball 13 may become dislodged from the seating 14 and allow the fluid to flow downwardly through the bore 9 and into the lower part 16 of the secondary cylinder 4. Certainly, when the intensifier piston reaches its starting point, the peg 15 will displace the ball 13 from its seating and, if this has not already happened the residual- fluid from the main cylinder 2 will drain away.
Whereas the invention has been described in terms of a piston movable upwardly and downwardly in a fixed cylinder, other apparatus may be devised without departing from the scope of the invention as defined by the Claims, for example in which the pistons move horizontally or, indeed, in which the main cylinder moves relatively to a fixed piston.
In a modification of the method of employing the apparatus, the main piston 1 is initially raised by external means, drawing fluid at less than atmospheric pressure into cylinder 2 through passage 9 and port 8. The air in cyliner 4 above head 6 of intensifier piston 5 is at atmospheric pressure, and thus holds the piston 5 in its lowermost position.
When the pressure fluid from the source increases to above that of the atmosphere, the movement of the piston takes place as previously described.
WHAT I CLAIM IS: 1. A coining press having pressure displacement means comprising a main cylinder, a main piston in the main cylinder and displaceable relatively thereto, a secondary cylinder adjacent to said main cylinder and connectable to a source of pressure fluid, an elongated intensifier piston, of which the head is of diameter greater than that of the shank, displaceable within the secondary cylinder under pressure of fluid from said source on said head whereby said shank, which extends from the secondary cylinder into the main cylinder, effects a relative displacement between the main piston and the main cylinder, means defining a passage for allowing pressure fluid to flow from the said source into the main cylinder to displace the main piston without displacement of the intensifier piston from a predetermined position, and means for closing said passage on such displacement of the intensifier piston.
2. A coining press according to Claim 1 wherein the secondary cylinder is vented to atmosphere behind the head of the intensifier piston.
3. A coining press substantially as described with reference to the drawing.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. than that of the face 11, the intensifier piston 5 will not move from its start position if the fluid pressure is so low that the pressure difference between the ends of the intensifier piston is not sufficient to overcome the friction of the intensifier piston bearings and seals 17 and the mass of the intensifier piston. However, when the rising main piston I closes upon the press head or upon the article to be pressed against the press head, and the pressure of fluid supplied from the source increases, the absolute value of the difference in the forces exerted on the upper face 11 and the lower face 10 of the intensifier piston increases to the point where it exceeds the aforementioned friction and mass, and the intensifier piston begins to rise in the cylinder 4. As the ball valve 12 clears the peg 15, the ball 13 is allowed to fall against the seating 14 and the passage defined by the bore 9 is closed, with fluid entrapped within the main cylinder 2. As the head 6 of the intensifier piston 5 rises in the cylinder 4, the main piston 1 rises in the main cylinder 2 with a reduced stroke and an increased force depending on the ratio of the areas of the surfaces 10 and 11 of the intensifier piston 5. The excessive pressure in the main cylinder 2 compared with the lower cylinder 4 ensures that the ball 13 is kept firmly against its seating 14. During the elevation of the intensifier piston in the secondary cylinder 4, air in the annular zone above the piston head 6 is vented through ports 18. When the pressing operation has been completed, using a pressing force derived from the pressure of the fluid multiplied by the ratio of the areas of the faces 10 and 11 of the intensifier piston, and it is desired to release the press, port 8 is disconnected from the fluid supply and is vented, whereupon the main and intensifier pistons lower in their respective cylinders under gravity. In other embodiments of the invention, not illustrated, the annular space above the head of the intensifier piston is occupied by pressure fluid from an alternative source, or a compression spring, more positively to sequence the operation and to facilitate the downward movement of the intensifier piston.As the main piston 1 withdraws from the press head, the pressure of fluid in the main cylinder 2 will diminish and the ball 13 may become dislodged from the seating 14 and allow the fluid to flow downwardly through the bore 9 and into the lower part 16 of the secondary cylinder 4. Certainly, when the intensifier piston reaches its starting point, the peg 15 will displace the ball 13 from its seating and, if this has not already happened the residual- fluid from the main cylinder 2 will drain away. Whereas the invention has been described in terms of a piston movable upwardly and downwardly in a fixed cylinder, other apparatus may be devised without departing from the scope of the invention as defined by the Claims, for example in which the pistons move horizontally or, indeed, in which the main cylinder moves relatively to a fixed piston. In a modification of the method of employing the apparatus, the main piston 1 is initially raised by external means, drawing fluid at less than atmospheric pressure into cylinder 2 through passage 9 and port 8. The air in cyliner 4 above head 6 of intensifier piston 5 is at atmospheric pressure, and thus holds the piston 5 in its lowermost position. When the pressure fluid from the source increases to above that of the atmosphere, the movement of the piston takes place as previously described. WHAT I CLAIM IS:
1. A coining press having pressure displacement means comprising a main cylinder, a main piston in the main cylinder and displaceable relatively thereto, a secondary cylinder adjacent to said main cylinder and connectable to a source of pressure fluid, an elongated intensifier piston, of which the head is of diameter greater than that of the shank, displaceable within the secondary cylinder under pressure of fluid from said source on said head whereby said shank, which extends from the secondary cylinder into the main cylinder, effects a relative displacement between the main piston and the main cylinder, means defining a passage for allowing pressure fluid to flow from the said source into the main cylinder to displace the main piston without displacement of the intensifier piston from a predetermined position, and means for closing said passage on such displacement of the intensifier piston.
2. A coining press according to Claim 1 wherein the secondary cylinder is vented to atmosphere behind the head of the intensifier piston.
3. A coining press substantially as described with reference to the drawing.
GB913877A 1978-02-27 1978-02-27 Coining presses Expired GB1600733A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB913877A GB1600733A (en) 1978-02-27 1978-02-27 Coining presses

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB913877A GB1600733A (en) 1978-02-27 1978-02-27 Coining presses

Publications (1)

Publication Number Publication Date
GB1600733A true GB1600733A (en) 1981-10-21

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Application Number Title Priority Date Filing Date
GB913877A Expired GB1600733A (en) 1978-02-27 1978-02-27 Coining presses

Country Status (1)

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GB (1) GB1600733A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0203794A1 (en) * 1985-05-29 1986-12-03 DAVY McKEE (POOLE) LIMITED Hydraulic RAM assembly
EP0164334B1 (en) * 1984-05-11 1988-07-27 ENFO Grundlagenforschungs AG Hydraulic cylinder with force multiplication
EP0516114A2 (en) * 1991-05-31 1992-12-02 Hemscheidt Maschinentechnik Schwerin GmbH & Co. Hydraulic closing apparatus for an injection mould
US5188014A (en) * 1990-02-14 1993-02-23 Dionizy Simson Hydraulic cylinder with pressure transmission
EP1293335A1 (en) * 2000-04-27 2003-03-19 Institute of Technology Precision Electrical Discharge Works Booster and press working device
EP1565373B2 (en) † 2002-11-25 2019-12-25 The Boeing Company Augmenting flight control surface actuation system and method

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0164334B1 (en) * 1984-05-11 1988-07-27 ENFO Grundlagenforschungs AG Hydraulic cylinder with force multiplication
EP0203794A1 (en) * 1985-05-29 1986-12-03 DAVY McKEE (POOLE) LIMITED Hydraulic RAM assembly
US5188014A (en) * 1990-02-14 1993-02-23 Dionizy Simson Hydraulic cylinder with pressure transmission
EP0516114A2 (en) * 1991-05-31 1992-12-02 Hemscheidt Maschinentechnik Schwerin GmbH & Co. Hydraulic closing apparatus for an injection mould
EP0516114A3 (en) * 1991-05-31 1993-04-07 Hermann Hemscheidt Maschinenfabrik Gmbh & Co. Hydraulic closing apparatus for an injection mould
EP1293335A1 (en) * 2000-04-27 2003-03-19 Institute of Technology Precision Electrical Discharge Works Booster and press working device
EP1293335A4 (en) * 2000-04-27 2005-03-09 Inst Tech Prec Elect Discharge Booster and press working device
EP1565373B2 (en) † 2002-11-25 2019-12-25 The Boeing Company Augmenting flight control surface actuation system and method

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Legal Events

Date Code Title Description
PS Patent sealed
PE20 Patent expired after termination of 20 years

Effective date: 19980226