Exhaust means for pneumatic power tool
AssigneeAtlas Copco Tools Aktiebolag
InventorSven P. J. Westerberg
Life of this patent
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Abstract
A sound depressing exhaust means for a pneumatic power tool with a substantially cylindrical housing (10) and a vane motor (11) with exhaust port means (23), has an annular casing (41) surrounding a portion of the housing (10), and four expansion chambers (31-32, 34, 36, 39) arranged in series and combined with four flow restrictions (33, 37, 30, 35) and a sound trap (38). All of the expansion chambers are annular and located concentrically relative to the tool housing (10), and one of the flow restrictions has an annular screen (37) separating two of these chambers (34, 36). The last two of the expansion chambers (36, 39) in the exhaust flow direction contain high frequency absorbing elements (43, 44) of foamed plastic.
Claims5
Sound depressing exhaust means for a pneumatic power tool having a substantially cylindrical housing (10) having a longitudinal axis, and a vane motor (11) which is disposed within said housing (10) and which has an exhaust port means (23) for expelling exhaust from the vane motor (11), the sound depressing exhaust means comprising:
- an annular casing (41) surrounding a portion of said housing (10);
- at least first, second and third expansion chambers (31-32, 34, 36) arranged in series with said exhaust port means (23) and being arranged in series in the downstream direction of exhaust flow relative to said exhaust port means (23), and said expansion chambers (31-32, 34, 36) communicating with said exhaust port means (23), one of said expansion chambers (36) being a last expansion chamber in the direction of said exhaust flow;
- wherein said third expausion chamber in the down steam exhaust flow direction contains a high frequency sound absorbing element therein
- at least two exhaust flow restrictions (37, 30) each communicating with and following in the downstream direction of said exhaust flow, one of said expansion chambers;
- and
- an outlet passage means (39) comprising a tube shaped entrance portion (38) extending in the axial direction of said substantially cylindrical housing (10) and said tube shaped entrance portion extending into said last one (36) of said expansion chambers, for thereby forming a sound trap.
Dependencies are inferred from the claim text.