Snap on flange for injection molding nozzle

1. A nozzle for an injection molding apparatus, comprising:

a nozzle body having a nozzle melt channel for receiving a melt stream from a manifold melt channel, the nozzle body having an integral flange, said flange having a first surface that contacts a manifold of the injection molding apparatus;

a collar removably mounted on the nozzle body, the collar having a first surface for supporting the flange of the nozzle body and a second opposing surface that contacts a mold plate; and

one of the nozzle body and the collar having a shoulder formed therein and the other of the nozzle body and collar having a radially disposed protrusion for engaging the shoulder to act against separation of the collar from the nozzle body.

2. The nozzle of claim 1 , wherein one of the nozzle body and the collar includes a further shoulder formed therein and the other of the nozzle body and the collar includes a further radially disposed protrusion for engaging the further shoulder to further act against separation of the collar from the nozzle body.

3. The nozzle of claim 1 , wherein the shoulder is an annular shoulder formed on an inner surface of the collar and the protrusion is an annular protrusion extending about a circumference of an outer surface of the nozzle body.

4. The nozzle of claim 3 , wherein the shoulder is provided by a surface of an annular recess formed on the inner surface of the collar.

5. The nozzle of claim 1 , wherein the shoulder is provided by a recess formed in a surface of one of the nozzle body and the collar.

6. The nozzle of claim 1 , wherein the shoulder is an annular recess extending about a surface of one of the collar and the nozzle body and the protrusion is an annular protrusion extending about a surface of the other of the collar and the nozzle body.

7. The nozzle of claim 1 , wherein the collar, nozzle body, shoulder and protrusion are respectively sized such that the collar can be mounted on the nozzle body by sliding the collar along a part of the nozzle body until the protrusion snaps by the shoulder, thereby providing an interference fit between the collar and nozzle body.

8. The nozzle of claim 1 , wherein the flange includes a second surface that opposes the first surface, wherein the second surface of the collar engages the second surface of the flange when mounted on the nozzle body.

9. The nozzle of claim 8 , wherein the collar includes an outer surface for engaging an annular surface of a mold plate recess for positioning the nozzle body relative to a gate.

10. A nozzle for an injection molding apparatus, comprising:

a nozzle body having a nozzle melt channel for receiving a melt stream from a manifold melt channel;

a collar removably mounted on the nozzle body; and

one of the nozzle body and the collar having a shoulder formed therein and the other of the nozzle body and collar having a radially disposed protrusion for engaging the shoulder to act against separation of the collar from the nozzle body, wherein the collar, nozzle body, shoulder and protrusion are respectively dimensioned to permit a limited amount of relative axial and radial movement between the collar and the nozzle body to account for differing thermal expansion properties of the collar and the nozzle body.

11. An injection molding apparatus, comprising:

a manifold having a manifold melt channel for receiving a melt stream of moldable material;

a mold plate spaced apart from the manifold and having a mold plate recess formed therein in alignment with a gate leading to a mold cavity;

a nozzle including

(i) a nozzle body with an upstream end coupled to the manifold and defining a nozzle melt channel for receiving the melt stream from the manifold melt channel, a portion of the nozzle body being received in the mold plate recess; and

(ii) a locating collar removably mounted to the nozzle body and having a surface engaging the mold plate for locating the nozzle body relative to the mold plate; wherein one of the nozzle body and the collar have a shoulder formed therein and the other of the nozzle body and collar have a radially disposed protrusion for engaging the shoulder to act against separation of the collar from the nozzle body,

wherein the nozzle includes a flange formed on the upstream end of the nozzle body, the flange having an upper surface contacting the manifold and a lower opposing surface, such that the collar extends from the lower surface of the flange to the mold plate, and wherein the flange and collar cooperating to align the nozzle melt channel with the manifold melt channel.

12. The injection molding apparatus of claim 11 , wherein the mold plate recess includes a mold plate shoulder about a periphery thereof set back from an opening to the mold plate recess, and the collar extends into the mold plate recess and engages the mold plate shoulder and a circumference of the mold plate recess.

13. The injection molding apparatus of claim 11 , wherein one of the nozzle body and the collar includes a further shoulder formed therein and the other of the nozzle body and the collar includes a further radially disposed protrusion for engaging the further shoulder to further act against separation of the collar from the nozzle body.

14. The injection molding apparatus of claim 11 , wherein the shoulder is an annular shoulder formed on an inner surface of the collar and the protrusion is an annular protrusion extending about a circumference of an outer surface of the nozzle body.

15. The injection molding apparatus of claim 14 , wherein the shoulder is provided by a surface of an annular recess formed on the inner surface of the collar.

16. The injection molding apparatus of claim 11 , wherein the shoulder is provided by a recess formed in a surface of one of the nozzle body and the collar.

17. The injection molding apparatus of claim 11 , wherein the shoulder is an annular shoulder extending about a surface of one of the collar and the nozzle body and the protrusion is an annular protrusion extending about a surface of the other of the collar and the nozzle body.

18. The injection molding apparatus of claim 11 , wherein the collar, nozzle body, shoulder and protrusion are respectively sized such that the collar can be mounted on the nozzle body by sliding the collar along a part of the nozzle body until the protrusion snaps by the shoulder, thereby providing an interference fit between the collar and nozzle body.

19. The injection molding apparatus of claim 11 , wherein the collar, nozzle body, shoulder and protrusion are respectively dimensioned to permit a limited amount of relative axial and radial movement between the collar and the nozzle body to account for differing thermal expansion properties of the collar and the nozzle body.