DEVICE IN A MOULD FOR MAKING HOLES OR RECESSES IN THE ARTICLE

Abstract: The invention relates to an arrangement pertaining to a mould for forming apertures or recesses in an object moulded preferably from porous or cell-structured material, the mould including mould-halves (14, 16) which are moveable relative to one another. One mould-half (16) carries at least one two-armed lever element (20), one arm (24) of which is provided with a mould-body (28) intended for forming the hole and the other arm (32) of which is intended, when the mould-halves are brought together, to abut an abutment surface (40) so as to hold the lever arm (24) provided with the mould-body (28) in a moulding position.

Description: DEVICE IN A MOULD FOR MAKIrøjHOLES OR RECESSES IN THE ARTICLE. The present invention relates to an arrangement pertain¬ ing to a mould for forming apertures or recesses in objects when moulding said objects from preferably porous or cell-structured material, said mould including relatively moveable mould halves which define therebe- tween a mould cavity for the object to be moulded when the mould halves are moved together and are closed one against the other. When moulding objects from porous or cell-structured materials, such as cycle helmets produced, for instance, from expanded polystyrene, polypropene or like material, the working environment of the moulding tools and their associated hydraulic or pneumatic mould-core drawing mechanisms often make it difficult and troublesome to achieve a long-lasting and reliable function. Against this background, it is an object of the present invention to provide a simple mechanical construction for manoeuvering mould cores or mould bodies by means of which apertures, hollows or recesses are formed in the object to be moulded, without the use of extensive and sensitive hydraulic or pneumatic mechanisms, said con¬ struction also being insensitive to the aforesaid envi¬ ronments. This object is achieved in accordance with the invention with an arrangement of the aforesaid kind, in that one mould half carries at least one two-armed lever element whose one arm is provided with a mould-body intended for forming said aperture or said recess and the other arm of which forms an operating arm which, when the mould halves are brought together, is intended to be brought into abutment with an abutment surface such as to hold the arm carrying said mould-body in a moulding position in which said mould-body is inserted into the mould cavity through an opening in one of said mould halves. The lever element is preferably an L-shaped element which is pivotally mounted on a journal block on the one mould half, wherein the abutment surface is formed on the other mould half. Suitably, the one mould half is moveably arranged while the other is fixed. The lever element may be biased towards a position that is remote from the moulding position, for instance by means of a spring device, so as to facilitate parting of the mould and also ejection of the moulded object with the aid of a known ejector device, subsequent to sepa¬ rating the mould halves one from the another. Other features and objects of the present invention will be apparent from the following Claims and also from the following description, which is made with reference to the accompanying drawing, in which Figure 1 is a sche- matic cross-sectional view of one inventive mould half intended for moulding a cycle helmet; and Figure 2 is a schematic view taken on the line A-A in Figure 1 and showing the configuration of the hole aperture formed in the helmet. Figure 1 is a part-sectional view of a mould, generally referenced 10, for moulding a cycle helmet 12. The mould comprises a fixed outer mould-half 14 and an inner mould-half 16 which is moveable in the directions of the arrows B and C. Attached to the underside of the move¬ able mould-half 16 is a bearing block 18 in which an essentially L-shaped two-armed lever 20 is mounted for pivotal movement about a pivot pin 22. The lever 20 includes a first lever arm 24 which carries at one end 26 thereof a mould core or mould-body 28 which functions to form an aperture through the wall of the helmet. In the illustrated case, a slot-like aperture 30 (see Figure 2) is formed so as to provide a means of attach¬ ment for a tightening strap, not shown. The lever 20 also comprises a second lever arm 32 having an upstanding projection 34 at its outer end. When the mould 10 is closed, the projection 34 extends through an opening 36 in a part 38 connected with the moveable mould-half 16 and lies in abutment with a lower abutment surface on a part 40 connected with the fixed mould half 14. In this operational state of the mould, the other end 26 of the lever 20 is held in sealing abutment against an opening 42 in the inner mould-half 16, where¬ in the mould-body 28 which forms the aperture in the helmet wall extends obliquely upwards towards a projec¬ tion 45 on the inside of the outer mould-half 14, this projection being intended to form a hollow at the mouth of the aperture 30. Although only one lever mechanism is shown in Figure 1, it will be understood that two or more such lever mecha¬ nisms may be disposed at desired positions around the helmet 12. In this regard, the levers 20 may be mutually connected by means of one or more pull springs 46 which function to bias the levers in the direction of the arrow B away from the moulding position, so as to faci¬ litate trouble-free ejection of the moulded helmet 12 with the aid of an ejector 48, when parting the mould. When moulding a cycle helmet 12 and forming therein a slot-like aperture 30 - or apertures or recesses of any other desired configuration - the moveable inner mould- half 16 is first moved in the direction of the arrow C to a closed moulding position in coaction with the outer, fixed mould-half 14. Each lever 20 herewith dogs the moveable mould-half 16 so that the upwardly extend¬ ing projection 34 of a respective lever arm 32 will come into abutment with the underside of the part 40 connect¬ ed to the fixed mould-half 14, it being ensured that the lever 20 will be swung clockwise around the pivot pin 22 into its moulding position and there held against the action of the spring 46. The end 26 of the second lever arm 24 therewith lies sealingly against the opening 42 in the mould-half 16 and the mould-body 28 that forms the slot-like aperture in the helmet 12 abuts its co- acting core-part 44. The moulding material, for instance, polystyrene, can then be expanded in the mould cavity, to form the desired helmet 12. Upon completion of the moulding operation, the moveable mould-half 16 is caused to move downwards in the direc¬ tion of the arrow B together with the moulded helmet 12, whereafter the ejector 48 is activated so as to lift the moulded helmet 12 from the mould-half 16 while, at the same time, swinging the arm 24 away in a counterclock- wise direction, with the aid of the spring 46.

Claims: Claims 1. An arrangement pertaining to a mould which is in- tended to form apertures or recesses in objects moulded, preferably, from porous or cell-structured material, comprising mould-halves (14, 16) which are moveable relative to one another and which when brought together and closed one against the other define therebetween a mould cavity for the object (12) to be moulded, c h a r a c t e r i z e d in that one mould-half (16) carries at least one two-armed lever (20) whose one lever arm (24) is provided with a mould-body (28) in¬ tended for forming said aperture or said recess, and whose other lever arm (32) forms an operating arm which, when the mould-halves (14, 16) are brought together lies in abutment with an abutment surface (40) so as to hold the mould-body carrying arm (24) in a moulding position in which the mould-body (28) is inserted into the mould cavity through an opening (42) in one mould-half (16). 2. An arrangement according to Claim 1, c h a r a c ¬ t e r i z e d in that the lever element (20) is gener¬ ally L-shaped. 3. An arrangement according to Claim 1 or 2, c h a r ¬ a c t e r i z e d in that the abutment surface (40) is provided on said second mould-half (14) . 4. An arrangement according to Claim 3, c h a r a c ¬ t e r i z e d in that the lever arm (32) which forms the operating arm has a projection (34) which, when the mould is closed, is intended to abut a part of said second mould-half (14) . 5. An arrangement according to any one of Claims 1- , c h a r a c t e r i z e d in that the lever element (20) is pivotally mounted in a bearing block (18) on one mould-half (16). 6. An arrangement according to any one of Claims 1-5, c h a r a c t e r i z e d in that one mould-half (16) is moveable and the other (14) is stationary. 7. An arrangement according to any one of Claims 1-6, c h a r a c t e r i z e d in that the mould-body (28) is provided on one end (26) of one lever arm (24), said end being configured to sealingly close the opening (42) in said one mould-half (16) in the moulding position of said arm. 8. An arrangement according to any one of Claims 1-7, c h a r a c t e r i z e d in that the lever element (20) is biased towards a position that is remote from the moulding position. 9. An arrangement according to Claim 8, c h a r a c ¬ t e r i z e d in that two or more lever elements (20) are arranged in groups and connect with a coacting spring device (46) for biasing the lever elements (20) away from their respective moulding positions.

Inventors: JOSEFSSON ALVAR, JOSEFSSON, ALVAR
Applicants: SCA EMBALLAGE CELLPLAST AB
Application year: 1992
Main classification: B29C33
IPC codes: B29C33