Description IMPROVED HINGE CONSTRUCTION AND THE MOLD FOR MAKING IT
BACKGROUND OF THE INVENTION
The present invention relates to an improved hinge construction and a mold for making it. A main requirement in making plastic material article of manufacture is that of reducing the making costs and time- As is known, in a case of simple articles and of article made in a large volume, any manual operations would greatly increase the cost of the single articles.
For plastic articles, comprising two or more portions made by injection molding methods, which must be assembled to one another, the assembling operations are very slow and expensive, with respect to the molding operations proper.
For example, a plastic vessel comprising two pivoted portions is usually made by injection molding methods . Then, the two molded pieces of the vessel must be manually assembled.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide an improved hinge construction which can be made in a single operating step, without the need of performing any further assembling operations of the parts forming the hinge or the article including said hinge . Within the scope of the above mentioned
aim, a main object of the present invention is to provide such an improved hinge construction which can be made by easily produced molds.
Yet another object of the present invention is to provide a hinge construction suitable for multiple uses .
According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by an improved hinge construction, comprising a first hinge portion, pivoted to a second hinge portion according to a pivoting axis, and being characterized in that said hinge construction comprises a central hinge portion coupled to the first hinge portion and including two axial elements extending from the central hinge portion in opposite directions and substantially coaxial with the pivot axis, said axial elements being adapted to engage annular portions, formed as a single piece with said second hinge portion, thereby said first hinge portion is pivoted to said second hinge portion according to a pivot axis substantially coinciding with the axial elements of the first hinge portion, the first and second hinge portions, the central hinge portion, the axial elements and annular portions being made by injection molding in a single step in an yet assembled and ready for use condition.
According to another aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are further achieved by a mold construction for making a hinge comprising a first
hinge portion pivoted to a second hinge portion according to a pivot axis, a central hinge portion coupled to the first hinge portion and comprising two axial elements extending from the central hinge portion in opposite directions and substantially coaxial with said pivot axis.
Said axial elements are provided for engaging respective annular portions, made as a single body with said second hinge portion, thereby the first hinge portion is pivoted to the second hinge portion along a pivot axis substantially coinciding with the axial elements of the first hinge portion.
The subject mold construction is characterized in that it comprises a male mold, a female mold and a pair of horizontal movable punches, operating at respective cylindric cavities, defined by said male and female molds at said pivot axis.
Each said cylindric cavity is provided with an end wall, including a central hole.
Each said punch comprises a punch end having a reduced cross-section, therethrough an axial hole extends, said axial hole extending for about the length of said reduced cross-section end portion. In the molding position, each said punch is fully engaged in its respective cavity and the reduced cross-section end abuts against the end wall thereby, as the plastic material is injected into the mold, the material coming from the first hinge portion will form the central hinge portion therefrom said axial elements extend.
Said axial elements, in particular, are
formed by causing the injected material to enter said axial hole in the end of the punch.
Simultaneously, the injection of the material coming from the second hinge portion will form the annular hinge portions, defined by a gap formed between the reduced cross-section end of the punch and the wall of said cavity.
BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the invention will become more apparent hereinafter from the following disclosure of a preferred, though not exclusive, embodiment of the invention, which is illustrated, by way of an indicative, but not limitative, example, in the accompanying drawings, where:
Figure 1 is a perspective view of a vessel provided with a hinge according to the invention;
Figure 2 is a further perspective view of the vessel shown in Figure 1, provided with a hinge construction and being shown in an open position;
Figure 3 is a detail inner perspective view of the vessel, provided with the hinge construction and being shown in an open position; Figure 4 is a detail outer perspective view of that same vessel, provided with a hinge construction according to the present invention and being shown in an open position;
Figure 5 is a top plan view of the female mold used for making the vessel shown in Figure 1 and including a hinge construction according to the present invention;
Figure 6 is a top plan view of the male mold for making the vessel shown in Figure 1, provided with a hinge construction according to the present invention, and being shown with the punches thereof in a withdrawn position;
Figure 7 is a detail top plan view of the mold for making said vessel, including a hinge construction according to the present invention, and being shown with the punches thereof in a withdrawn condition;
Figure 8 is a detail top plan view of the mold for making the vessel, including a hinge construction according to the present invention, and being shown with the punches thereof in a molding position;
Figure 9 is an enlarged cross sectional view substantially taken through the section plane IX-IX of Figure 8;
Figure 10 is a cross sectional view of the hinge according to the invention and of a portion of the vessel;
Figure 11 is an enlarged perspective view of the hinge detail of the female mold; and
Figure 12 is an enlarged perspective view of the detail related to the hinge construction of the male mold, which is shown with the punches thereof in a withdrawn position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the number references of the above mentioned figures, the hinge construction according to the invention, which has been generally
indicated by the reference number 1, is adapted for application to two elements to be pivoted to one another such as two portions, respectively 2 and 3, of a vessel, generally indicated by the reference number 4, having a threaded opening 5 and provided for holding therein the ends of electric cable, for example at a junction thereof.
In this connection, it should be however pointed out that the hinge construction according to the present invention can be applied to any desired types of vessel or other articles, comprising two pivoted portions .
In the following disclosure reference will be made to a vessel or housing for electric elements, and this exclusively by an illustrative example.
The hinge construction according to the invention comprises a central hinge portion 6 coupled to a first hinge portion 3 to be pivoted and including two axial elements 7 extending from the central hinge portion 6 in opposite direction and substantially i coaxial with the rotary or pivot axis of the hinge.
Said axial elements 7 are designed for engaging annular portions 8 formed as a single-piece with the second hinge portion 2 to be pivoted, thereby the first hinge portion 3 will be pivoted to the second hinge portion 2 according to a hinge pivot axis substantially coinciding with the axial elements 7 of the first hinge portion 3. According to the invention, the hinge portion 2 and 3 and, respectively, said axial elements and annular portions are made by a single
injection molding operation, directly in the operating condition, in which the axial elements 7 are engaged in the annular portions 8, without the need of carrying out any further assembling operations .
The hinge construction according to the present invention is made by a mold construction, generally indicated by the reference number 100, comprising a male mold 102, a female mold 103 and a pair of horizontal movable punches 104.
Said movable punches, in particular, operate at the cylindric cavities 105 defined by the male and female molds, at the hinge 1.
Each cylindric cavity 105, which is mirror- like equal to the other, is provided with an end wall 106, including a central hole 107.
As shown in the figures of the accompanying drawings, the end wall 106 and central hole 107 are defined by two elements, each formed in the respective male and female mold which, upon closing thereof, will define the end wall and central hole.
Each punch 104 comprises a reduced cross- section end 108, therethrough an axial three-lobe hole 109 passes, said hole extending through about the length of the reduced cross section end portion.
In the molding position, shown in figures 8 and 9, each punch 104 is fully engaged in its respective cavity 105, the reduced cross section end portion abutting against the end wall 107. Thus, by injecting the plastic material into the mold, the material coming from the first hinge portion 3 will form the central hinge portion 6
therefrom the two axial elements 7 would extend, as is shown in figure 8.
More specifically, said axial element 7 are formed by the penetrating material injected into the axial hole 108 of the end portion of the punch.
Simultaneously, the injection of the plastic material coming from the second portion 2 will form the annular portions 8 defined by the gap formed between the reduced cross-section end 108 of the punch 104 and the wall of the cavity.
Upon ending the molding operation, the punches 104 will be withdrawn, as is clearly shown in figures 7 and 12.
The arrows shown in figure 12 indicate the insertion movement of the punches during the previous molding step or operation.
Upon molding, the mold will be opened and the formed piece withdrawn therefrom, possibly by using ejecting devices 110. The molded piece, ejected from the mold, is provided in an assembled and ready for use condition, with its hinge perfectly made and operating, without the need of performing any subsequent assembling operations . The axial elements 107 are engaged in their respective annular portions and can freely rotate, without any possibilities of disengaging from one another, unless a disassembable hinge construction must be provided. This would be obtained, for example, by using materials allowing a plastic deformation of the hinge forming elements, in order to allow the axial
elements to be disengaged from the annular portions .
It has been found that the invention fully achieves the intended aim and objects.
In particular, an improved hinge construction has been provided, which can be made by injection molding in a single step without any further assembling operations.
The article in which the hinge construction is included will be ejected from the mold in a perfectly finished condition, ready for packaging or any other intended applications .
In practicing the invention, the used materials, as well as the contingent size and shapes, can be any depending on the requirements and according to the status of the art.