Lid construction for breathing apparatus

1. A breathing assistance apparatus comprising:

a lid and a main body, the lid and the main body selectively enclosing a cavity configured to hold a body of liquid; and

at least one hinge assembly connecting the lid to a rear portion of the main body, the at least one hinge assembly comprising:

at least one post mounted to the lid;

at least one support mounted to the main body, wherein the at least one support comprises a recess comprising a mouth that opens in a rearward direction, the recess configured to receive at least a portion of the at least one post;

a clip extending along at least an axial length of the at least one post, the clip being positioned on an opposite side of the at least one post from the at least one support such that the at least one post is captured between the clip and the at least one support;

a cam structure having a sloping surface such that the cam structure tapers toward a tip and a thickness of the cam structure decreases from a base of the cam structure toward the tip; and

a guide structure having an opposing surface configured to engage the sloping surface of the cam structure such that the sloping surface and the opposing surface resist movement of the lid relative to the main body in a lid detachment direction when the lid is in an at least partially closed position,

the at least one hinge assembly adapted to provide restraint against air pressure within the apparatus in use,

wherein, when the lid is in an open position, the lid can be separated from the main body with application of a sufficient force without breakage of either the at least one support or the at least one post.

2. The apparatus of claim 1 , wherein the lid further comprises a button member and a component adapted to be engaged with one or more fingertips while the button member is depressed.

3. The apparatus of claim 2 , wherein the button member is spring-biased away from the at least one hinge assembly.

4. The apparatus of claim 1 , wherein the lid further comprises a button member that is spring biased away from the at least one hinge assembly.

5. The apparatus of claim 4 , wherein the at least one hinge assembly allows pivotal movement of the lid relative to the main body.

6. The apparatus of claim 1 , wherein the at least one hinge assembly allows pivotal movement of the lid relative to the main body.

7. The apparatus of claim 6 , wherein the guide structure and the cam structure are configured to cause sliding movement of the at least one post during rotation of the at least one post.

8. The apparatus of claim 1 , wherein the guide structure and the cam structure are configured to cause sliding movement of the at least one post during rotation of the at least one post.

9. The apparatus of claim 1 , wherein the guide structure and the cam structure are configured to cause sliding movement of the at least one post during rotation of the at least one post, wherein the guide structure comprises a recess configured to receive the cam structure, and wherein when the lid is in the open position, the guide structure is sufficiently spaced from the cam structure such that the lid can be separated from the main body with application of the sufficient force.

10. The apparatus of claim 9 , wherein the sliding movement only occurs when the lid is moved from a disengaged state to an engaged state with respect to the main body.

11. The apparatus of claim 1 , wherein when the lid is in the open position, the lid can be separated from the main body with the at least one post fixed to the lid.

12. The apparatus of claim 1 , wherein the recess of the at least one support comprises a rearwardly-opening mouth configured to receive the at least one post.

13. The apparatus of claim 1 , wherein the main body comprises the cam structure.

14. The apparatus of claim 1 , wherein the lid comprises the guide structure.

15. A breathing assistance apparatus comprising:

a lid and a main body, the lid and the main body selectively enclosing a cavity; and

at least one hinge assembly connecting the lid to a rear portion of the main body, the at least one hinge assembly comprising at least one post mounted to the lid and at least one support mounted to the main body, wherein the at least one support comprises a recess configured to receive at least a portion of the at least one post, the at least one hinge assembly comprising a clip extending along at least an axial length of the at least one post, the clip being positioned on an opposite side of the at least one post from the at least one support such that the at least one post is captured between the clip and the at least one support,

wherein the main body comprises a cam structure having a sloping surface such that the cam structure tapers toward a tip and the lid comprises a guide structure having a recess configured to receive the cam structure and an opposing surface configured to engage the sloping surface such that the sloping surface of the cam structure and the opposing surface of the guide structure engage each other and resist detachment of the lid from the main body when the lid is in an at least partially closed position, and

wherein when the lid is in an open position, the guide structure is sufficiently spaced from the cam structure such that the lid can be separated from the main body in a rearward direction with application of a sufficient force without breakage of either the at least one support or the at least one post and without removal of the at least one post from the lid.

16. The apparatus of claim 15 , wherein the lid further comprises a button member and a component adapted to be engaged with one or more fingertips while the button member is depressed.

17. The apparatus of claim 15 , wherein the lid further comprises a button member that is spring-biased away from the at least one hinge assembly.

18. The apparatus of claim 15 , wherein the guide structure and the cam structure are configured to cause sliding movement of the at least one post during rotation of the at least one post.

19. The apparatus of claim 15 , wherein an entirety of the guide structure is positioned outboard of the at least one support.