EP0300017A1 - Vis et appareil de moulage servant a fabriquer de telles vis - Google Patents

Vis et appareil de moulage servant a fabriquer de telles vis

Info

Publication number
EP0300017A1
EP0300017A1 EP19880901428 EP88901428A EP0300017A1 EP 0300017 A1 EP0300017 A1 EP 0300017A1 EP 19880901428 EP19880901428 EP 19880901428 EP 88901428 A EP88901428 A EP 88901428A EP 0300017 A1 EP0300017 A1 EP 0300017A1
Authority
EP
European Patent Office
Prior art keywords
screw
screws
mould
array
slot
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.)
Ceased
Application number
EP19880901428
Other languages
German (de)
English (en)
Inventor
Stephen Whetstone
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.)
SEAC Ltd
Original Assignee
SEAC 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
Priority claimed from GB878702432A external-priority patent/GB8702432D0/en
Application filed by SEAC Ltd filed Critical SEAC Ltd
Publication of EP0300017A1 publication Critical patent/EP0300017A1/fr
Ceased legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B37/00—Nuts or like thread-engaging members
    • F16B37/14—Cap nuts; Nut caps or bolt caps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
    • B29C45/14336—Coating a portion of the article, e.g. the edge of the article
    • B29C45/14426—Coating the end of wire-like or rod-like or cable-like or blade-like or belt-like articles

Definitions

  • This invention relates to plastic headed screws and to apparatus for producing plastic headed screws, bolts and the like by an injection moulding process.
  • Metal fixings such as pins and nails
  • a plastic head by a simple injection moulding process in which the head of the pin or nail is encased in moulded plastic.
  • Such pins are highly decorative and are in much demand for fixing laminated plastic sheeting, for example in the interior finishing of caravans and boats.
  • a mould block is provided, containing a linked series of mould cavities into which molten plastic can be injected in the usual way.
  • the mould cavities are formed, so that the head of a metal pin is accommodated in the cavity while the shank of the pin rests in a cylindrical housing leading from the mould cavity in the block.
  • slot used in this specification, we mean not only a straight cross-slot of the conventional type which is open at each end, but also the various types of closed-end slot, including straight close-end slots, and cross-shaped slots of various patterns, e.g. Phillips and 'Torx' - type screws, as well as polygonal cavities of the Allen type.
  • the apparatus is based on the provision of screwdriver-like projections which are biased into the mould cavities and can be turned until they engage the slots. According to the invention, therefore, there is provided injection moulding apparatus for the manufacture of plastic headed metal screws, including
  • each projecting member or each screw means for rotating each projecting member or each screw about its longitudinal axis and for biasing each projecting member or screw towards a cavity so as to cause each projecting member to engage each slot.
  • a small degree of bias towards the mould cavities is essential for each screw or projecting member, so that as it is turned it can move axially so that the projecting member engages the slot. While the biassing can be achieved by suitable springing, we find that in one preferred embodiment of the invention, the members or screw array are arranged so as to be able to drop under the influence of gravity.
  • the moulding apparatus is formed with two cooperating components: a first component comprising a first mould plate including an array of housings in communication with apertures in a face of said first plate to accommodate the shank portions of the screws; and a second component comprising a second mould plate provided with a complementary array of housings in communication with apertures in one face of the second mould plate, each housing accommodating a projecting member; means being provided for bringing the two said faces into abutment and cavities being formed in one or both of said faces and arranged so as to form, when the two faces are in contact and screws are located in the first mould plate, an array of mould cavities surrounding the heads of the screws.
  • the cavities may be in either of said faces, but it is convenient to have the cavities communicating with the housings carrying the projecting members.
  • a base plate carries the array of housings for the screw shanks and an upper plate carries the housings for the projecting members, each of the latter housings opening into a mould cavity, the two plates being hinged for close abutment.
  • screws can easily be inserted into _ the housings in the base plate, the upper plate can be lowered into contact, thus forming a series of moulds surrounding the screw heads. Then, as the projecting members are turned, they can drop into alignment in the slots.
  • Such an embodiment is particularly suited to plastic heads which are domed, frustroconical etc.
  • one mould plate includes an array of cavities, each including a projecting member which is fixed, while the other mould plate includes an array of housings for screws, each housing including gripping means for holding a screw firmly so that it projects into the mould cavity formed between the abutted mould plates.
  • the means for rotation is arranged to provide rotation to the screws rather than to the projecting members. It will be seen that this embodiment is a simple corollary of the first embodiment.
  • each projecting member or screw gripping means is provided with a pinion in the form of a collar and a rack is provided into which the pinions can mesh. Linear movement of the rack then rotates each of the projecting members or screws.
  • the members or screw gripping means can be provided with pinions which interlink in a gear train.
  • Other analogous forms of drive train can be envisaged.
  • a projecting means can be located inside a generally tubular driven housing so as to be rotatably engaged therewith.
  • the tubular housing is provided with a terminal collar having an axial aperture having the profile of the slot-engaging portion of the projecting member, e.g. a cross-shaped aperture for a Phillips-type screwdriver head. The projecting member then passes through the aperture and is rotationally driven by the housing and collar at any degree of axial movement of the projecting member.
  • a housing for a screw-gripping means can be similarly constructed.
  • housings for the screw shanks and the housings for the projecting members must offer a close fit. in order to prevent leakage of injected plastic.
  • Figure 1 represents a schematic sectional view of the apparatus at the point of moulding
  • Figure 2 is a plan view in the direction A-A.
  • Figure 3 is a plan view in the direction B-B.
  • Figure 4 represents a plan view of an alternative embodiment in the direction A-A of Fig. 5, similar to that in Figure 2, but with details of the train of pinions shown in cutaway
  • Figure 5 represents a schematic part-sectional view of the alternative embodiment to that shown in Figure 1; and Figure 6 is a sectional view of a . screw head.
  • the apparatus in one embodiment, comprises a lower mould plate 1 carrying an array of 24 cylindrical housings 2 to accommodate screw shanks. The diameter of the housings 2 is such that an inserted screw sits with its head proud of the top surface.
  • An upper mould plate 3 is mounted for pivotal movement on a support 4.
  • the upper mould plate 3 carries an array of 24 housings 5 communicating with mould cavities 6.
  • the mould cavities 6 are all connected to a branched conduit 7 serving to direct injected plastic to each of the mould cavities 6.
  • each housing 5 Housed within each housing 5 is a projecting member 8 having a screwdriver-like end 9 for engagement with a screw slot. Immediately above the mould plate 3, each projecting member 8 is provided with a pinion collar 13 arranged in mesh with a linear toothed rack 14.
  • the upper mould plate 3 is hinged upwards to expose the housings 2 in the lower mould plate 1. Screws are dropped into plate, their slots being randomly oriented. The upper mould plate 3 is then lowered into position in close abutment with the lower mould plate 1. At this point, the upstanding heads of the screws are housed within the mould cavities 6 and most, if not all of the projecting members are not yet located in the screw slots. The rack 14 is then caused to move, thus rotating the pinions 13, causing the projecting members 5 to rotate. As each projecting member 5 aligns with its screw slot, it drops under gravitational bias to engage the slot. Further rotation of the projecting member 5 then merely rotates the screw in the housing 2.
  • the upper mould plate 3 can be provided with spring biasing means 15a to complement (or replace) the effect of gravity.
  • the upper mounting plate 10 is brought into contact with the upper mould plate 3.
  • the pistons 12 which are provided with spring biasing means 15 are aligned with, and come into contact with, the tops of periphery members 5.
  • the mould is then clamped together. Any projecting members 5 which may not have dropped and located in their respective slots (because of faults in screws etc) are thus protected from damage by the clamping force.
  • Molten plastic e.g. polypropylene or acetal, is injected via conduit 7 into- - each of the mould cavities 6. The finished screws are then removed from the apparatus by again hinging upward the upper mould plate 3.
  • the housings 5 in the upper plate 3a, 3b are replaced by generally tubular housings 16 having an inner bore 17 in which the projecting member 8 is located.
  • the inner bore 17 is reduced to a smaller aperture 18 having a cross-section matching that of the driving end 19 of the projecting member 8.
  • the driving end 19 has a cross-section matching the profile of the screw slot (e.g. a Phillips 'cross' pattern) throughout its length.
  • a driven pinion collar 13 is mounted on the tubular housing 16. Rotation of the tubular housing 16 thus causes rotation of the projecting member 8 (by direct drive on the driving end 19) regardless of the relative axial position of the projecting member 8 in the tubular housing 16.
  • FIG. 6 shows a sectional view of the head of a screw manufactured according to the present invention.
  • a conventional countersunk head 23 Phillips-type screw having a conventional 'cross'- shaped slot 24 is encapsulated by an integral solid plastic head 25 having a complementary slot 26 which forms an extension of the screw slot 24.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)

Abstract

Une vis ou un boulon en métal (23) avec tête en plastique comprend une fente (26) pour tourne-vis qui est ménagée dans la tête en plastique (25) et qui s'aligne sur une fente pour tourne-vis complémentaire (24) avec laquelle elle communique, cette dernière fente étant ménagée dans la vis ou le boulon en métal (23). Un appareil de moulage par injection servant à fabriquer des vis en métal avec tête en plastique comprend: des organes définissant un réseau de cavités de moule (6), qui sont pourvues de conduits de connexion (7) pour le plastique injecté et qui sont chacune formées de façon à recevoir la tête d'une vis en métal (23); un réseau complémentaire d'éléments saillants (8), qui sont chacun formés de façon à s'engager dans la fente (24) d'une desdites vis (23) et qui sont placés de façon à s'étendre dans une cavité de moule (6); et des organes servant à faire tourner chaque élément saillant (8) ou chaque vis (23) autour de son axe longitudinal et à solliciter chaque élément saillant (8) ou chaque vis (23) en direction d'une cavité, pour permettre à chaque élément saillant (8) de s'engager dans ladite fente (24).
EP19880901428 1987-02-04 1988-02-04 Vis et appareil de moulage servant a fabriquer de telles vis Ceased EP0300017A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB8702432 1987-02-04
GB878702432A GB8702432D0 (en) 1987-02-04 1987-02-04 Screw & moulding apparatus
GB08800015A GB2202599A (en) 1987-02-04 1988-01-04 Plastics headed metal screws or bolts
GB8800015 1988-01-04

Publications (1)

Publication Number Publication Date
EP0300017A1 true EP0300017A1 (fr) 1989-01-25

Family

ID=26291866

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19880901428 Ceased EP0300017A1 (fr) 1987-02-04 1988-02-04 Vis et appareil de moulage servant a fabriquer de telles vis

Country Status (2)

Country Link
EP (1) EP0300017A1 (fr)
WO (1) WO1988005873A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012019849B4 (de) * 2012-10-10 2023-11-02 Böllhoff Verbindungstechnik GmbH Bauteil mit Dichtstopfen sowie Verfahren zum Einformen eines Bauteileinsatzes

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB916161A (en) * 1957-10-31 1963-01-23 Sidney Geoffrey Young Improvements in or relating to fixing devices
US3078334A (en) * 1959-07-20 1963-02-19 Formar Ind Inc Insert molded plastic self tapping fastener
US3085461A (en) * 1960-08-01 1963-04-16 Formar Ind Inc Molded plastic fastener having a sheet metal core element
US3238287A (en) * 1962-04-27 1966-03-01 Illinois Tool Works Method for encapsulating a headed member with a molten material
DE1216027B (de) * 1963-03-29 1966-05-05 Fritz Kirchhoff Kopfschraube aus Kunststoff

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8805873A1 *

Also Published As

Publication number Publication date
WO1988005873A1 (fr) 1988-08-11

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