GB2289612A - Tobacco smokers' mouthpieces - Google Patents

Abstract

Tobacco smokers' mouthpieces, typically a cigarette holder, for limiting or reducing the effect of tars and other harmful constituents is shown typically in Figure 6 to comprise a tubular body 110 forming a socket 114 for holding a cigarette 16 at its upstream end and having a downstream end portion 118 held in the users mouth with a baffle insert 112 removably located in the body. The insert includes three baffles 122, 124 and 126 between which are defined upstream and downstream chambers 132, 136; the baffles having restricted flow passages therethrough. The upstream baffle has only a single venturi passage 128; the intermediate baffle 124 has only limited through passages 134 somewhat greater in effective cross-sectional area than the venturi passage; and the downstream baffle 126 may have a single central passage 139, the arrangement giving a two-stage pressure drop for better combustion and/or deposit within the insert of harmful gases and tars. <IMAGE>

Description

TOBACCO SMOKERS' MOUTHPIECES This invention relates to mouthpieces for cigarette or cigar holders or tobacco pipes hereinafter collectively referred to as "smokers mouthpieces" of the kind including baffles and other restricted flow devices for limiting or reducing the effect of harmful constituents of the tobacco smoke such dS tars etc.

There have een various proposals for nouthpieces of this kind incorporating filters, baffles etc; for example U.S.- 2954772 describes a mouthpiece incorporating a baffle having a single very small through aperture so that smoke drawn through it is accelerated to a high velocity acting in conjunction with an impingement barrier upstream thereof intended to collect tar and similar constituents.

The object of the present invention is to provide a smokers mouthpiece which is more effective in removing or reducing harmful effects of constituents of the tobacco smoke.

According to the invention there is provided a smokers mouthpiece, comprising a tubular body whose upstream end forms or is connected to a cigar or cigarette receiving socket or tobacco pipe bowl in use, a median portion of the body defining at least two axially disposed chambers separated from each other and from upstream and downstream end portions of the mouthpiece by retarding baffles having restricted flow passages through which smote is drawn in use; a first of said baffles at the upstream end of the chambers having only a single restricted venturi bore opening into an upstream one of said chambers, a second said baffle separating the latter chamber from a further chamber downstream thereof having only restricted flow passage or passages therethrough somewhat greater in total effective cross sectional area than said venturi bore, and a downstream said baffle separating the chambers from said downstream end portion being a body forming the end wall of the most downstream chamber and having one or more through passages opening into the downstream end portion of the mouthpiece.

Preferably there are two chambers defined by said first, second and third baffles and conveniently the baffles are parts of a unitary insert by being linked and spaced by a longitudinal member or members, the insert being removable from the body for cleaning or, possibly, disposal and replacement.

Examples of the invention, in the form of a cigarette holder, are now more particularly described with reference to the accompanying drawings, wherein; Figure 1 is a diagrammatic longitudinal section of an assembled holder being a first embodiment of the invention, Figure 2 is a section on line 2-2 of Figure 1, Figure 3 is a section on line 3-3 of Figure 1, Figure 4 is a section on line 4-4 of Figure 1, Figure 5 is a perspective view of a baffle insert of the holder of Figure 1, Figure 6 is a diagrammatic longitudinal section of an alternative form of assembled holder being a second embodiment of the invention, and Figures 7 to 10 are like sections and a like perspective view of a baffle insert of the holder of Figure 6.

The first embodiment of smokers' mouthpiece, described with reference to Figures 1 to 5, is a cigarette holder formed in two parts, a tubular body 10 and a baffle insert 12 removably located in the body. An upstream end portion of the body serves as a socket 14 to hold a cigarette 16 in use and the downstream end portion 18 of body 10 is shaped in conventional manner to be held in the user's mouth.

The median portion of body 10 is cylindrical of uniform diameter with socket 14 e.g. about lOmm in diameter. Body 10 is conveniently formed of plastics or similar materials.

Insert 12 is preferably a one piece or fabricated metal formation, e.g. brass and comprises an axial stem 20 centred in body 10 and three axially spaced baffles 22, 24 and 26 whose peripheries are in sealing contact with the interior of body 10. For some applications one or more of the baffles may include O-rings or other sealing means. For simple construction, they may merely be a snug push fit within body 10 to provide acceptable sealing and to locate the insert at the same time, permitting its withdrawal through socket 14 for cleaning or replacement.

The first baffle 22, which is at the upstream end of body 10 immediately adjacent to socket 14 has a dished upstream face and a single central fine venturi bore 28 typically 0.5mm diameter. The downstream face of baffle 22 is coned to merge with stem 20 and bore 28 opens into three fine radial slots 30 (Figure 2) angled at about 15 deg. to the axis at the junction of baffle 22 with stem 20.

The upstream end of stem 20 within slots 30 forms an initial impingement barrier; when suction is applied to draw smoke from cigarette 16 the flow will be speeded to a high velocity through the venturi bore 28 and will slow again within slots 30 and, in particular, when it enters an upstream chamber 32 defined between baffles 22 and 24.

This encourages the separation and deposit of tars and like substances from the smoke onto the surfaces of insert 12 as an initial purification stage.

The second or intermediate baffle 24 is a disc having, in this example, only three small apertures 34 spaced equiangularly about its axis, typically each aperture is approximately lmm diameter. Thus the total effective cross sectional area of the through passages in baffle 24 is many times that of venturi aperture 28 but still provides substantial restriction and localised speeding of the through flow.

Thus; as smoke is drawn through, there will be a substantial pressure drop or degree of vacuum within chamber 32.

downstream chamber 36 is defined between baffle 24 and the downstream baffle 26.

The latter baffle is a conical formation tapering in the downstream direction. The upstream face of baffle 26 surrounding stem 20 is concave as shown in Figure 1 and the only through apertures past baffle 26 are angularly spaced small section grooves 38 extending in the axial direction along the coned periphery. This baffle again retards flow so that there will also be pressure drop within chamber 36.

The overall length of insert 12 may be about 20mm, the length has been exaggerated in the drawings.

Referring now to Figures 6 to 10, the second embodiment is also a cigarette holder having the same form of tubular body 110, but with a removable baffle insert 112 of rather different construction positioned between the downstream end portion 118 shaped as a mouthpiece and the upstream end portion serving as a socket 114 to hold a cigarette 16.

Insert 112 comprises three axially spaced baffles 122, 124 and 126 interconnected in spaced relationship by longitudinal side bars 120 instead of a central stem, forming a cage-like unit. A continuous tube could be substituted for bars 120.

The first baffle 122, at the upstream end, has a dished upstream face and complementary coned downstream face giving d constant axial thickness, for example of about 5mm. It has a single central fine venturi bore 128 typically 0.5mm diameter opening upstream into upstream chamber 132. Three fine side passages 129 opening equiangularly from the downstream face of baffle 122 coverage towards its axis to join bore 128 within the baffle, enhancing the venturi effect.

The second or intermediate baffle 124 is a disc having, in this example, only four small apertures 134, each 0.5mm bore: one on the central axis and three spaced equiangularly therearound. These open into downstream chamber 136.

The third and downstream baffle 126 has the same bodily shape as baffle 26 of the first embodiment but has no peripheral grooves or openings. Instead it has a single central through bore 139, in this example lmm diameter.

The operation is similar to that of the first embodiment. Suction will draw the cigarette smoke initially into passages 129 and bore 128 which speed it to high velocity followed by slowing and pressure drop within chamber 132 for separation and deposit of tars etc on inner surfaces of that chamber. The total crosssection area of apertures 134 in intermediate baffle 124 is many times that of venturi bore 128, though still providing a second stage restriction and local speeding of through flow and a degree of vacuum or pressure drop in chamber 132. Likewise baffle 126 causes pressure drop in chamber 136.

The three stage baffling or retardation is believed to substantially improve the abstraction of tars from the smoke so that they collect on the surfaces of insert 12 without reaching downstream end portion 18.

The Inultiple (in the examples double) chamber arrangement is also believed to encourage snore effective combustion or other disposal or degrading of harmful gasses such as carbon monoxide. By analogy with boiler combustion chamber technology the baffles of the example provide a double pass action on the gasses flowing through the mouthpiece accompanied by a two stage pressure drop. A 14 inch .rXg vacuum is easily maintained in d large de-aerator several feet long using a small steam jet acting in conjunction with a small orifice.

Similarly a significant pressure drop will take place in the successive chambers when a user draws on the downstream end portion, initially exhausting air from said chambers which will be replaced by smoke at low pressure. It is believed this pressure drop may contribute to a rise in temperature assisting in burning off carbon monoxide before it reaches the user's mouth.

It is to be understood that restricting orifices of other sizes and arrangement might be employed, for example there could be less or more openings in intermediate baffle 24 or 124, and/or the sizing, number and disposition of grooves 38 or other opening or openings in downstream baffle 26 might be varied. or some applications said grooves may spiral round the conical periphery instead of being straight.

while cigarette holders have been described the mouthpieces shown in the drawings could also take the form of cigar holders or could form the stems of tobacco pipes leading from a bowl connected to socket 14 or 114.

Claims (15)

1. A smokers mouthpiece comprising a tubular body whose upstream end forms or is connected to a cigar or cigarette receiving socket or tobacco pipe bowl in use, a median portion of the body defining at least two axially disposed chambers separated from each other and from upstream and downstream end portions of the mouthpiece by retarding baffles having restricted flow passages through which smoke is drawn in use; a first of said baffles at the upstream end of the chambers having only a single restricted venturi bore opening into an upstream one of said chambers, a second said baffle separating the latter chamber from a further chamber downstream thereof having only restricted flow passage or passages therethrough somewhat greater in total effective cross sectional area than said venturi bore, and a downstream said baffle separating the chambers from said downstream end portion being a body forming the end wall of the most downstream chamber and having one or more through passages opening into the downstream end portion of the mouthpiece.

2. A mouthpiece as in Claim 1 having two chambers defined by said baffles with the first baffle immediately adjacent to said socket or pipe bowl in use and the third baffle immediately adjacent the part of the body operatively held in the user's mouth.

3. A mouthpiece as in Claim 1 or 2 wherein the baffles form parts of a unitary insert by being linked and spaced by a longitudinal member or members for removable location in the body.

4. A mouthpiece as in Claim 3 wherein the baffles are linked and spaced by an axial stem.

5. A mouthpiece as in Claim 3 wherein the baffles are linked and spaced by longitudinal side bars or a tube.

6. A mouthpiece as in any preceding claim wherein the baffles and chambers are about 10mum in diameter.

7. A mouthpiece as in any preceding claim wherein the first baffle has a dished upstream face with a single central fine venturi bore communicating between said upstream face and the upstream chamber.

8. A mouthpiece as in Claim 7 wherein said venturi bore is 0.5mm in diameter.

9. A mouthpiece as in Claim 7 or 8 wherein the second baffle is a disc having a plurality of through passages.

10. A mouthpiece as in Claim 9 wherein the second baffle has only three through passages each approximately lam in diameter.

11. A mouthpiece as in Claim 9 wherein the second baffle has only four through passages, each 0.5mm in diameter.

12. A mouthpiece as in any preceding claim wherein the third baffle has a concave upstream face and through passages defined in conjunction with the inner wall of the body as angularly spaced small section grooves along the baffle periphery.

13. A mouthpiece as in anyone of Claims 1 to 11 wherein the third baffle has a concave upstream face with only a single central through passage.

14. A mouthpiece as in Claim 13 wherein said central through passage is lmm in diameter.

15. A smokers mouthpiece substantially as hereinbefore described with reference to Figures 1 to 5; or with reference to Figures 6 to 10 of the accompanying drawings.