GB2186228A

GB2186228A - Moulding nozzles

Info

Publication number: GB2186228A
Application number: GB08701742A
Authority: GB
Inventors: Leonard Law
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-01-28
Filing date: 1987-01-27
Publication date: 1987-08-12
Also published as: GB2186228B; GB8602074D0; GB8701742D0

Abstract

A nozzle for use with low pressure injection moulding or casting apparatus comprises a tubular member 4 having a first end 4A for attachment to a moulding material feed tube (not shown), and a second opposite end 4B adapted to engage in a mould casing, said second end having a float 16 which is movable from a first position, in which moulding material may flow from the feed tube into the mould, Fig. 1, to a second position so as to close off the flow of material from said feed tube and to prevent backward flow of said material from said mould when injection pressure ceases. The float 16 is connected by an inner spindle to a flag 20 which is able to provide a visual indication of the position of the float 16 in use of the nozzle. <IMAGE>

Description

SPECIFICATION Moulding nozzles This invention relates to moulding, pouring and casting apparatus, and more particularly to the nozzles, both inlet or fill and outlet or vent, which are used in the apparatus when forming articles by injection moulding, pouring or casting.

The invention is particularly, although not exclusively, concerned with the nozzles used in co-operation with moulds and apparatus for injection moulding, pouring or casting of sanitary ware such as baths, wash hand basins and so on.

According to the present invention there is provided, a nozzle for use with low pressure injection moulding, pouring or casting apparatus and comprising a tubular member having a first end for attachment to a moulding material feed tube, and a second opposite end adapted to engage in a mould casing, said second end having a float which is movable from a first position, in which moulding material may flow from the feed tube into the mould, to a second position so as to close off the flow of material from said feed tube and to prevent backward flow of said material from said mould when injection pressure ceases.

Preferably, said nozzle will be elongate and will be composed of a synthetic plastics material.

The float of said nozzle will preferably be of generally hemispherical form and will seat in a recess in the second end of the nozzle, and will preferably be carried on one end of the spindle extending through the tubular member.

At the first end of said tubular member the spindle will preferably have a "flag" or other means so as to indicate the position of the float at the opposite end of the tubular member.

In order that the invention may be more readily understood, an embodiment thereof will now be described, by way of example, reference being made to the accompanying drawings, wherein: Figure 1 is a perspective view of a fill or inlet nozzle in accordance with the present invention; Figure 2 is a side elevation showing the nozzle of Fig. 1 in a first mode of operation; and Figure 3 is a view similar to Fig. 2 but showing the nozzle in a second mode of operation.

Referring to the drawings, a nozzle, indicated generally by reference numeral 2, comprises an elongate tubular body member 4 having first and second ends 4A and 4B respectively.

As will be seen from the drawing, the first end 4A which is adapted to be attached to the moulding material feed tube (not shown), has a tapered end 6 close to which is a portion 8 of greater diameter so that a seal may be effected between the nozzle and the wall of the feed tube.

Downstream of the portion 8, i.e. towards the second end 4B, the tubular member is provided with a collar 10 which serves the purposes of limiting the degree of penetration of the nozzle into the aforementioned feed tube and as a clamping collar to the member itself.

At the opposite end of the tubular member, i.e. at the end 4B, there are provided two grooves in which are located two O-rings 12 and 14. The end 4B is adapted to be located in a mould casing (not shown), and the 0rings 12 and 14 will provide a seal between the nozzle and the mould casing.

The end 4B of the tubular member 4 is recessed and adapted to seat in this recess is a substantially hemispherical float 16 which is connected, through the intermediary of a spindle 18 within the tubular member 4, to a "flag" 20 at the end 4A.

The tubular member 4 is preferably composed of a synthetic plastics material.

In use, with the nozzle located and clamped between the moulding material feed tube and the mould casing, moulding material is fed from the feed tube, through the nozzle 2 and into the mould, the passage of material being faciliated by the float 16 being off its seating.

When the mould is full of material, i.e. when the injection pressure has stopped, the float 16 will seat on its seating in the end 4B of the tubular member to prevent back flow of the moulding material. The diameter of the recess in the end 4B of the tubular member is a good tolerance fit with the float 16 so as to prevent the aforementioned back flow of material.

The above-described nozzle is, as stated, adapted to be located at the inlet or fill end of the mould, and a similar nozzle is adapted to be located at the outlet end. The outlet end or vent nozzle, consisting again of a tubular member having a float and a "flag" connected through the intermediary of a spindle-as described previously-allows venting of trapped gases past the unseated float during injection of material into the mould and, when the mould is full the moulding material urges the float to its seated position so as to prevent escape of moulding material. The "flag" at the open end of the nozzle is pushed up when the float seats and acts as a visual signal that the mould cavity is full and that therefore injection can cease. The square section "X" adjacent the collar 10 is designed to facilitate easy removal from the mould and in addition by turning the nozzle neck e.g. a spanner in engagement with the square section, it enables the sprue or feed area of waste material to be broken off from the moulded article once the moulding material has hardened and cooled.

Thus the invention provides an effective and efficient means of controlling the flow of moulding material in an injection moulding process or in the pouring or casting of articles, and the venting of trapped gases, which has been found to be considerably cheaper than conventional means.

It is intended that the nozzles be disposed of after moulding is complete.

Claims

1. A nozzle for use with low pressure injection moulding, pouring or casting apparatus and comprising a tubular member having a first end for attachment to a moulding material feed tube, and a second opposite end adapted to engage in a mould casing, said second end having a float which is movable from a first position, in which moulding material may flow from the feed tube into the mould, to a second position so as to close off the flow of material from said feed tube and to prevent backward flow of said material from said mould when injection pressure ceases.

2. A nozzle according to Claim 1, wherein said float is of generally hemsipherical face and is adapted to seat in a recess in said second end of said nozzle.

3. A nozzle according to Claim 1 or Claim 2, wherein said float is carried on one end of a spindle which extends through and which is freely movable in said tubular member.

4. A nozzle according to any of Claims 1 to 3, wherein said spindle carries at its end remote from the float a "flag" or other means so as to indicate the position of the float in use of the nozzle.

5. A nozzle according to any of Claims 1 to 4, wherein said second end of said nozzle is provided with sealing means in the form of O-rings.

6. A nozzle according to any of the preceding Claims, wherein the nozzle is elongate and is composed of a synthetic plastics material.

7. A nozzle constructed and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.

8. Moulding, pouring or casting apparatus including a nozzle substantially as herein described with reference to and as illustrated in the accompanying drawings.