Pneumatic drill device

1. A pneumatic drill device comprising:

an assembly and an outer casing,

said assembly including a cylinder defining a bore and a movable piston, said piston in said bore configured to actuate a pick element, a supply device for supplying the bore with compressed air, and an operational control device,

said outer casing being formed from two complementary sections defining an internal cavity enclosing said assembly, said outer casing defining at least one channel in fluid communication with said bore, said at least one channel extending from said internal cavity and formed partially through the thickness of at least one of the casing sections.

2. The pneumatic drill device according to claim 1 , wherein said assembly is rigidly fixed between said casing sections which are clamped against one another in sealed manner.

3. The pneumatic drill device according to claim 1 , wherein said casing sections are adapted in shape so as to house, in their linked portion, said assembly, which are thus sandwiched between the two assembled casing sections.

4. The pneumatic drill device according to claim 1 , wherein said casing sections comprise at least one layer of material adapted to insulate vibrations and operating noise from the assembly.

5. The pneumatic drill device according to claim 1 , wherein said casing sections are formed by moulding of synthetic materials.

6. The pneumatic drill device according to claim 1 , wherein said casing sections are adapted to the use of a small lightweight drill for finish drilling or drilling with limited access.

7. The pneumatic drill device according to claim 1 , wherein said casing sections are two half-shells made of plastics.

8. The pneumatic drill device according to claim 1 , wherein one of said casing sections includes a peripheral bead received in a corresponding groove defined by the other said casing section.

9. The pneumatic drill device according to claim 1 , wherein said casing sections define at least one operating handle configured to receive the operational control device.

10. The pneumatic drill device according to claim 9 , wherein the handle is offset from the axis of the cylinder and includes a front branch and a rear branch configured in the shape of a “D”, the front branch configured to protect the operator's hand.

11. The pneumatic drill device according to claim 10 , wherein said at least one channel is a first exhaust baffle configured to vent air out of the bore without interfering with the operator's hand.

12. The pneumatic drill device according to claim 11 , wherein the casing sections define a residual cavity extending from the internal cavity and in fluid communication with said at least one channel for collecting any air leaks from said assembly.

13. The pneumatic drill device according to claim 10 , wherein the rear branch incorporates a supply tubing at an outer end and a supply valve connected to the control device, said supply tubing in fluid communication with said at least one channel.

14. The pneumatic drill device according to claim 1 , wherein said at least one channel is configured to vent an amount of air between said piston and said pick element towards the pick element.

15. A pneumatic drill device according to claim 1 , wherein said casing sections are symmetrical.

16. A pneumatic drill device according to claim 1 , wherein said at least one channel is elongated in a direction from a proximal end and a distal end of said cylinder and is configured to selectively communicate an amount of air from said supply device to said bore when said piston is positioned near said distal end.