Testing of cigarettes and other similar rod-like articles

Claim 2

In a cigarette testing device for detecting flaws in the wrappers of filter-tipped cigarettes including means producing a pressure differential between the inside and outside of the wrapper of each cigarette in turn at a testing station to induce an air flow through the wrapper and means to detect any leaks in the wrapper produced by the said differential pressure, the improvement comprising means for applying a full pressure differential in the region of the joint between the filter and the smokable part of each cigarette, and reducing means for applying a reduced pressure differential in a selected region occupied substantially entirely by at least part of the smokable part of the cigarette.

Claim 3

A cigarette testing device according to claim 1 in which each cigarette is carried during testing by a fluted drum, and in which the means for reducing the pressure differential along part of the wrapper comprises a number of pressure-reducing members carried by a second drum arranged adjacent said fluted drum so that one of the pressure-reducing members lies adjacent to each cigarette during testing, said testing station being situated between the two drums.

Claim 4

A cigarette testing device according to claim 2 in which each pressure-reducing member forms part of an assembly which includes part of the fluted drum and which closely surrounds part of the cigarette at the testing station so as to reduce the flow of air through the part of the cigarette wrapper which is thus closely surrounded.

Claim 5

A cigarette testing device according to claim 2 in which the pressure differential is produced by means of suction in an annular chamber around the cigarette at the testing station, the annular chamber being defined by the two drums, and the suction being connected to each annular chamber at the testing station via a suction space in the second drum.

Claim 6

A cigarette testing device according to claim 4 in which each pressure-reducing member comprises a part which restricts free communication between the suction space and the annular space to a slot in the second drum in the region of the joint between the filter and the smokable part of the corresponding cigarette.

Claim 9

Apparatus for testing filter-tipped cigarettes each comprising a filter portion joined to one end of a tobacco portion including a wrapper, the apparatus comprising: a. means for carrying the cigarettes successively through a testing station; b. means for forming an enclosure around each cigarette in turn while at the testing station, whereby an annular space is formed between the cigarette and the enclosure, the annular space extending over the joint between the tobacco and filter portions and also over at least part of the tobacco portion; c. means for producing a pressure differential between the annular space and the interior of the cigarette to induce an air flow to test for the presence of any leaks; and d. means for varying the pressure at different points along the annular space whereby the said pressure differential is greater in the region of the joint than it is in the region of the tobacco portion.

Claim 10

Apparatus for testing filter-tipped cigarettes each comprising a filter portion joined to one end of a tobacco portion including a wrapper, the apparatus comprising: a. means for carrying the cigarettes successively through a testing station; b. means for forming an enclosure around each cigarette in turn while at the testing station, whereby an annular space is formed between the cigarette and the enclosure, the annular space extending over the joint between the tobacco and filter portions and also over at least part of the tobacco portion; c. means for producing a pressure differential between the annular space and the interior of the cigarette to induce an air flow to test for the presence of any leaks; and d. means for varying the pressure at different points along the annular space whereby the said pressure differential is greater in the region of the joint than it is in the region of the tobacco portion.

Claim 11

Apparatus according to claim 7, further comprising means defining a slot for feeding suction to the annular space, the said means for varying the pressure comprising means for restricting the flow of air into the slot from the part of the annular space which extends over the tobacco portion of the cigarette.