US3827845A - Presses - Google Patents

Presses Download PDF

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Publication number
US3827845A
US3827845A US00336077A US33607773A US3827845A US 3827845 A US3827845 A US 3827845A US 00336077 A US00336077 A US 00336077A US 33607773 A US33607773 A US 33607773A US 3827845 A US3827845 A US 3827845A
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US
United States
Prior art keywords
press head
plunger
piston
bores
plungers
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 - Lifetime
Application number
US00336077A
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English (en)
Inventor
R Matthews
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.)
African Explosives and Chemical Industries Ltd
Original Assignee
African Explosives and Chemical Industries Ltd
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 African Explosives and Chemical Industries Ltd filed Critical African Explosives and Chemical Industries Ltd
Application granted granted Critical
Publication of US3827845A publication Critical patent/US3827845A/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • B30B15/06—Platens or press rams
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
    • B30B11/02—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses using a ram exerting pressure on the material in a moulding space
    • B30B11/04—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses using a ram exerting pressure on the material in a moulding space co-operating with a fixed mould

Definitions

  • ABSTRACT This invention relates to press heads and is concerned with such press heads for use in compacting particulate material into self supporting or substantially self supporting articles.
  • the invention is particularly, but not exclusively, concerned with such press heads for use in the manufacture of elements in the explosives industry as detonator charges and time delay elements.
  • a press head comprising a hollow body member, a plurality of parallel bores in the body and all being connectable to a source of pressure, a plurality of parallel piston members slidable respectively within the .bores, a plurality of plungers associated respectively with the pistons in such a manner that there is a pressure transferring relationship between the pistons and their associated plungers, the plungers projecting from the body so that they may be introduced into dies to compress particulate material therein, there being provided a connection to drain between the ends of each bore and a sealing means to prevent pressure fluid passing beyond the drain connection, the sealing means comprising an impervious hollow member which is sealed to the body and which surrounds the associated plunger at least at the drain connection and a skirt sealed to the piston and extending beyond the hollow inember so that any pressure fluid passing the piston will pass directly
  • Each plunger may be integral with the piston but preferably the piston and plunger are formed separately and are preferably located in butting relationship.
  • the preferred butting relationship is for the piston to have a conical recess on its underside and for the plunger to have a pointed upper end of smaller cone angle than the recess.
  • Each plunger may be a one piece element preferably having an enlarged upper portion and a lower portion of smaller cross section but it may be formed in two parts which are preferably in butting relationship.
  • the lower parts in both these arrangements are the parts which are adapted to engage the particulate material.
  • each piston may preferably contact the base of the chamber to limit the movement of the piston.
  • This lower edge is preferably provided with fluid escape openings, preferably by being castellated, to allow any fluid entering the space between the skirt and the impervious. hollow member to escape from this space.
  • an article formed from particulate material compressed in a press as set out above.
  • FIG. 1 is an elevation, partially in section, of a press head of the invention.
  • FIG. 2 is a detail of a modified plunger.
  • FIG. 3 is a diagrammatic representation of a press to which the press head of FIG. 1 is applied, and FIGS. 4a, 4b, 5 and 6 show the operation of compacting the particulate material into dies.
  • FIGS. 1 and 3 there is shown a press head 10 which is bolted to the fixed upper platen 12 of an hydraulic press 14.
  • the lower platen 16 of the press 14 is mounted for movement by an hydraulic ram 18 and normally carries a spoon assembly 20 (see FIGS. 4, 5 and 6) in which dies or sleeves 82 are mounted.
  • the press head 10 comprises a main body 24 that is formed in three parts 26, 28 and 30 which are bolted and sealed together.
  • the middle part 28 has a number of parallel bores 32 formed therein.
  • the upper part 26 has an enlarged recess 34 in its lower face. This recess forms a main hydraulic chamber and all the bores 32 communicate with this chamber 34.
  • the lower part 30 has a recess 36 in its upper face. This recess forms a drain chamber and all the bores 32 open into the drain chamber 36.
  • the bores 32 have continuation portions 37 of slightly smaller cross section in the lower part 30 below the drain chamber 36.
  • each bore 32 Slidably received within each bore 32 is a hollow piston 38 that has a relatively large nominal clearance in the bore 32 which clearance is slightly more than one percent of the bore diameter.
  • the piston 38 has an elongated skirt 40 for the purpose which will be described. The lower edge of the skirt 40 will normally engage the base 43 of the drain chamber 36, when the piston 38 is in its lowermost position and this lower edge of the skirt 40 is castellated at 42.
  • the underside of the piston 38 has formed therein a concentric conical recess 44 which has a fairly large cone angle.
  • a plunger 46 is associated with each piston 38.
  • Each plunger 46 has an upper portion 48 of larger cross section than its lower portion 50.
  • the two portions 48 and 50 are connected by a frusto-conical portion 52.
  • the upper portion 48 has a conically pointed end 49 having a smaller cone angle than the recess 44.
  • the lower portions 50 pass respectively through openings 54 in a carrying plate 56 secured to the lower head part 30 and registering openings 58 in a movable stripper plate 60.
  • the openings 54 each have a greater diameter than the plunger portions 50 that pass through them so that they, the openings 54, provide neither lateral support nor substantial frictional contact with these portions 50.
  • the upper ends of the openings 54 are provided with conical inlets 61 of the same cone angle as the portions 52 and being adapted to act as seats for these portrons.
  • the openings 58 provide guides for the plunger portions 50. At their upper ends, the openings 58 have conical lead in portions 62 for the plunger ends.
  • the stripper plate 60 is carried by a number of hollow rods 63 which pass through the carrying plate 56 and are prevented from moving through the plate by flanges 64.
  • the rods 63 are slidable on guide rods 66 and biassed downwardly by compression springs 68.
  • An oil barrier tube 70 is fitted in fluid tight manner in each bore continuation portion 37.
  • Each oil barrier tube 70 surrounds its associated plunger 46 with clearance and extends up the skirt 40 of the piston 38 to define an elongated passage therewith. Indeed the upper ends of the tube 70 are close to the underside of the piston when the latter is in its lowermost position.
  • the drain chamber 36 is connected via a conduit 72, which is air vented, to the oil sump.
  • the main hydraulic chamber 34 is connected to a source of pressure and one side of a cylinder (not shown) arranged in parallel therewith.
  • a control piston In the cylinder is a control piston the stroke of which is adjustable.
  • the plunger 46a is formed in two separate parts namely an upper larger diameter part 48a having a conical upper end 49a which is similar to the end 49 and a lower smaller diameter part 50a.
  • the lower end 74 of the part 48a is enlarged and forms a slidable guide in the oil barrier tube 70.
  • This end 74 engages an enlarged head 76 on the lower part 50a.
  • This head 76 prevents the lower part 50a from escaping through the carrying plate 56a.
  • the openings 54a in the carrying plate 560 are plain cylinders.
  • the spoon assembly 20 which (as shown in FIGS. 4 to 6) comprises a base plate 78, an apertured plate 80 for receiving the element sleeves 82 and the cover plate 84 which rests on the sleeves 82 are placed on the platen 16 with the sleeves 82 in position and with the particulate material in the sleeves 82.
  • Pressure fluid is now supplied to the ram 18 which lifts the platen l6 and the spoon assembly 20 until the cover plate 84 engages the stripper plate 60 and lifts the latter.
  • the lower ends of the plungers 46 now pass through the openings 58 (the lead-ins to which are omitted in FIGS. 4 to 6) in the stripper plate 60 and then through openings in the cover plate 84 until these ends engage the particulate material in the sleeves.
  • the pressure supply to the ram is interrupted to hold the ram stationary for a predetermined period of time after which the pressure supply will be reversed and the ram will be lowered to its starting position and the spoon assembly 20 may be removed and be replaced by a freshly charged spoon assembly.
  • the press is arranged so that there will be a small clearance 86 when the spoon assembly carries sleeves 82a for the manufacture of the delay elements of the maximum size (as seen in FIG. 4). This means that where smaller elements are being made the clearance will be very substantial as seen in FIG. 5, and consequently the ram will have to make a fairly long movement without doing any useful work.
  • packings 88 can be provided which will lift the spoon assembly off the platen so that there will be substantially the same clearance between the upper face of the cover plate 84 and stripper plate for all sizes of elements.
  • the press head can be used on a conventional press with the minimum of modifications.
  • the apparatus can be used for compacting any particulate material, for example, in the pharmaceutical industry where it is essential that the material is not contaminated.
  • its main use is for compacting elements in the explosives industry such as the charge of detonators and time delay elements and for inserting delay elements into detonators.
  • the invention is not limited to the precise constructional details hereinbefore described and illustrated in the drawings.
  • pressure equalising rings can be provided in the peripheries of the skirts of the pistons if desired.
  • a press head comprising a hollow body member, a plurality of parallel bores in the body and all being connectable to a source of pressure, a plurality of parallel piston members slidable respectively within the bores, a plurality of plungers associated respectively with the pistons in such a manner that there is a pressure transferring relationship between the pistons and their associated plungers, the plungers projecting from the body so that they may be introduced into dies to compress particulate material therein, there being provided a connection to a drain between the ends of each bore and a sealing means to prevent pressure fluid passing beyond the drain connection, the sealing means comprising an impervious hollow member which is sealed to the body and which surrounds the associated plunger at least at the drain connection and a skirt sealed to the piston and extending beyond the hollow member so that any pressure fluid passing the piston will pass directly into the drain connection and will be prevented by the sealing means from coming into contact with the plunger.
  • each plunger is integral with the associated piston.
  • a press head as claimed in claim 1 further comprising a guide plate movable relative to the body member, the guide plate havingtherein a plurality of guide bores through which the ends of the plungers remote from the pistons respectively slidably pass.
  • each plunger comprises a portion of larger cross section adjacent the piston and a portion of smaller cross section located remote from the piston and adapted to engage and compact the particulate material.
  • a press head as claimed in claim 13 further comprising means located between the body and the guide plate and having openings therein through which the plungers respectively pass and wherein each opening has a tapering seat which the tapered section of the associated plunger engages to limit movement of the plunger out of its bore.
  • a press head as claimed in claim 16 further comprising means located between the body and the guide plate and having openings therein through which the smaller cross section portions of the plungers respectively pass and wherein the smaller cross section portion of each plunger has a projection to engage the said means to prevent the smaller cross section portion of the plunger passing through the said means.
  • a press head as claimed in claim 1 wherein the bores open into a chamber which is connectable via a conduit to a sump and which constitutes the drain connection.
  • a press head as claimed in claim 20 further comprising fluid escape openings in the edge of the skirt to enable fluid entering under the skirt to escape therefrom.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Press Drives And Press Lines (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
US00336077A 1972-03-29 1973-02-26 Presses Expired - Lifetime US3827845A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
ZA722167A ZA722167B (en) 1972-03-29 1972-03-29 Improvements in presses

Publications (1)

Publication Number Publication Date
US3827845A true US3827845A (en) 1974-08-06

Family

ID=25564697

Family Applications (1)

Application Number Title Priority Date Filing Date
US00336077A Expired - Lifetime US3827845A (en) 1972-03-29 1973-02-26 Presses

Country Status (12)

Country Link
US (1) US3827845A (it)
AT (1) AT323561B (it)
AU (1) AU458529B2 (it)
BE (1) BE797548A (it)
CA (1) CA962119A (it)
CH (1) CH566864A5 (it)
DE (1) DE2315029A1 (it)
FR (1) FR2178043B1 (it)
GB (1) GB1369775A (it)
IT (1) IT977539B (it)
ZA (1) ZA722167B (it)
ZM (1) ZM4273A1 (it)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100513986C (zh) * 2006-08-01 2009-07-15 杭州强立机械有限公司 工业雷管专用压力机及压缩雷管炸药的方法
CN104610001A (zh) * 2015-01-12 2015-05-13 福建海峡科化股份有限公司 一种复合式延期体生产装置及生产方法
CN109760332A (zh) * 2019-02-21 2019-05-17 上海珂明注塑系统科技有限公司 盖与勺点胶装配自动化设备与生产系统
CN110375601A (zh) * 2019-08-28 2019-10-25 雅化集团绵阳实业有限公司 一种耐高温大电阻自动失效雷管及其制造工艺
CN111592438A (zh) * 2020-06-02 2020-08-28 雅化集团绵阳实业有限公司 圆盘单发雷管压药装置及其使用方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2490515B1 (it) * 1980-09-22 1982-09-03 Alliages Frittes Sa

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2209404A (en) * 1937-07-06 1940-07-30 Hydraulics Inc Apparatus for the manufacture of hollow and indented dry pressed ceramic ware
US2627086A (en) * 1949-09-17 1953-02-03 Baker Brothers Inc Molding machine
US2667679A (en) * 1949-06-01 1954-02-02 Frederick H Jackman Apparatus for molding building blocks
US3379120A (en) * 1966-12-07 1968-04-23 Harry C. Fogle Bun molding apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2209404A (en) * 1937-07-06 1940-07-30 Hydraulics Inc Apparatus for the manufacture of hollow and indented dry pressed ceramic ware
US2667679A (en) * 1949-06-01 1954-02-02 Frederick H Jackman Apparatus for molding building blocks
US2627086A (en) * 1949-09-17 1953-02-03 Baker Brothers Inc Molding machine
US3379120A (en) * 1966-12-07 1968-04-23 Harry C. Fogle Bun molding apparatus

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100513986C (zh) * 2006-08-01 2009-07-15 杭州强立机械有限公司 工业雷管专用压力机及压缩雷管炸药的方法
CN104610001A (zh) * 2015-01-12 2015-05-13 福建海峡科化股份有限公司 一种复合式延期体生产装置及生产方法
CN109760332A (zh) * 2019-02-21 2019-05-17 上海珂明注塑系统科技有限公司 盖与勺点胶装配自动化设备与生产系统
CN109760332B (zh) * 2019-02-21 2024-04-19 上海珂明注塑系统科技有限公司 盖与勺点胶装配自动化设备与生产系统
CN110375601A (zh) * 2019-08-28 2019-10-25 雅化集团绵阳实业有限公司 一种耐高温大电阻自动失效雷管及其制造工艺
CN110375601B (zh) * 2019-08-28 2022-02-01 雅化集团绵阳实业有限公司 一种耐高温大电阻自动失效雷管及其制造工艺
CN111592438A (zh) * 2020-06-02 2020-08-28 雅化集团绵阳实业有限公司 圆盘单发雷管压药装置及其使用方法
CN111592438B (zh) * 2020-06-02 2021-08-17 雅化集团绵阳实业有限公司 圆盘单发雷管压药装置及其使用方法

Also Published As

Publication number Publication date
FR2178043B1 (it) 1975-04-04
FR2178043A1 (it) 1973-11-09
DE2315029A1 (de) 1973-10-18
AU458529B2 (en) 1975-02-27
CA962119A (en) 1975-02-04
IT977539B (it) 1974-09-20
BE797548A (fr) 1973-07-16
AU5256673A (en) 1974-08-29
ZA722167B (en) 1973-11-28
GB1369775A (en) 1974-10-09
ZM4273A1 (en) 1974-12-20
AT323561B (de) 1975-07-25
CH566864A5 (it) 1975-09-30

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