Hand-wheel adjusting the outlet of a tap for gas cylinder

1. A hand-wheel for adjusting at least one of an outlet pressure and a flow-rate of a tap for a gas cylinder, said hand-wheel comprising:

a body;

a transparent cover fixed on the body; and

indicia arranged between the transparent cover and the body so as to be visible by a user but not in contact with the fingers of the user;

wherein the body comprises a central cavity for housing a gauge or a digital display visible through the transparent cover; and

wherein the body comprises an outer ring portion forming an annular surface exclusively carrying the indicia.

2. The hand-wheel according to claim 1 , wherein the body comprises a front face, at least one of the indicia being arranged on the front face.

3. The hand-wheel according to claim 2 , wherein the front face of the body supporting the at least one indicia forms an annular rim portion.

4. The hand-wheel according to claim 1 , wherein the transparent cover comprises a front face and a rear face, at least one of the indicia being arranged on the rear face.

5. The hand-wheel according to claim 1 , wherein the indicia are printed on at least one of the body and the transparent cover.

6. The hand-wheel according to claim 5 , wherein indicia are printed by screen printing.

7. The hand-wheel according to claim 1 , wherein the indicia are distributed evenly along a periphery of the hand-wheel.

8. The hand-wheel according to claim 1 , wherein the transparent cover is generally disk-shaped with a front face and a rear face, the cover comprising on the rear face at least two bosses configured for receiving threaded portions of fastening screws engaged through holes in the body, from a rear face of the body.

9. The hand-wheel according to claim 8 , wherein the body comprises recesses receiving the bosses, respectively.

10. The hand-wheel according to claim 8 , wherein the transparent cover comprises on the front face of the cover ribs extending radially, each boss on the rear face of the cover being located in front of one of the ribs.

11. The hand-wheel according to claim 1 , wherein the transparent cover comprises at its periphery an annular portion that encircles the body.

12. The hand-wheel according to claim 1 , further comprising a gasket extending between the body and the transparent cover at the periphery of the hand-wheel.

13. A tap for gas cylinder, said tap comprising:

a body with an inlet, an outlet and a passage connecting the inlet with the outlet;

a device in the passage for varying at least one of the pressure and flow-rate at the outlet, the device comprising a rotating element for adjusting at least one of the pressure and flow-rate; and

a hand-wheel mounted on the rotating adjusting element of the device, wherein the hand-wheel comprises:

a body;

a transparent cover fixed on the body; and

indicia arranged between the transparent cover and the body so as to be visible by a user but not in contact with the fingers of the user;

wherein the body comprises a central cavity for housing a gauge or a digital display visible through the transparent cover; and

wherein the body comprises an outer ring portion forming an annular surface exclusively carrying the indicia.

14. The tap according to claim 13 , wherein the body comprises a central cavity for housing a gauge or a digital display visible through the transparent cover, the rotating element of the device is supported by a fixed shaft, and the tap further comprises an electronic indicator with a digital display housed in the cavity of the body of the hand-wheel, and electric wires connected to the indicator and extending through a longitudinal bore in the shaft of the device.

15. A tap assembly, said assembly comprising:

a tap for gas cylinder; and

a cover housing the tap, wherein the tap comprises:

a body with an inlet, an outlet and a passage connecting the inlet with the outlet;

a device in the passage for varying at least one of the pressure and flow-rate at the outlet, the device comprising a rotating element for adjusting at least one of the pressure and flow-rate;

a hand-wheel mounted on the rotating adjusting element of the device, wherein the hand-wheel comprises:

a body;

a transparent cover fixed on the body; and

indicia arranged between the transparent cover and the body so as to be visible by a user but not in contact with the fingers of the user; and wherein the cover housing the tap comprises an opening receiving the hand-wheel and a mark on an outer surface of the cover at the edge of the opening, the mark forming a reference for the indicia of the hand-wheel.