Filter Structure For Tobacco Products Particularly For Cigarettes And Cigars, As Well As For Cigarette Holders, Tobacco Pipes And The Like

Abstract

A filter structure provides two concentric annular passages surrounding a central exhaust passage, hot smoke passing in one axial direction through the outer annular passage, then in the opposite axial direction through the inner annular passage and finally in the one axial direction through the central exhaust passage. A plurality of fine radially oriented passages guide the smoke from the outer annular passage to the inner annular passage. An annular pocket is provided at the downstream end of the outer annular passage beyond the fine radially oriented passages for receiving accumulated tobacco sauce consisting of tars and condensed water. Heat from the smoke permits a distillation process to be carried on in the outer passage while a condensation process is conducted in the cooler inner exhaust passage.

Parent Case Text

This application is a continuation of Ser. No. 190,868, filed Oct. 20, 1971, now abandoned.

Description

BACKGROUND OF THE INVENTION

In prior art filters a plurality of telescoping or interlocking spaced members, which define a smoke passage are provided. They have the great disadvantage in so far as prolonged smoking caused a deposit of tobacco sauce consisting of tobacco tars and condensed water on the bottom part of the casing in the area of the smoke passages, which are positioned on the same level. In a relatively short time, this deposit causes clogging of the latter. Self-filtering of the smoke by the self-produced tobacco sauce does not occur, thus the filtering effect is unsatisfactory, nor does the conventional tobacco smoke filter provide an acutal condensation and distillation process which is imperative for efficient filtering.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a filter structure for tobacco products to extract both nicotine and tar. With the present invention a surprisingly high amount, averaging 75 percent nicotine, based on the nicotine content of the smoke, and 70 percent tars, based on the tars content of the smoke, are removed according to laboratory tests.

BRIEF DESCRIPTION OF THE DRAWING

Other objects of this invention will appear in the following description and appended claims, reference being made to the accompanying drawing forming a part of the specification wherein like reference characters designate corresponding parts in the several views.

FIG. 1 shows a longitudinal section through the filter (enlarged several times),

FIG. 2 is a plan view of the filter of FIG. 1,

FIG. 3 shows a longitudinal section through a portion of the casing of the filter, and

FIG. 4 shows a diverting tube, partially as a sectional view.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A casing 1 is provided at the outer end with a widened adaptor member 1' to hold a cigarette or cigar 11 and at the other end an annular bottom part 2. An internal exhaust tube 5 coaxially extending through the casing 1 is secured around the outlet opening 4 in the bottom part 2. The casing 1 and the exhaust tube 5 are formed as a unit and made of synthetic material. A plastic diverting tube 6 extends through the area between the casing 1 and the exhaust tube 5. The exterior end of the diverting tube 6 is closed by a cover 3, and the diverting tube 6 is provided with four crosswise projecting guiding ribs 10. The diverting tube 6 is open at the bottom and is provided with a plurality of recesses which are hardly visible to the unaided eye. A step-like foot part 5' is provided with a ring-shaped shoulder 12 and spaced above is an upwardly tapered connecting part 12'. When inserting the diverting tube 6 into the casing 1, the guiding ribs 10 together with the connecting part 12' effect the centering of the diverting tube 6 between the casing 1 and the exhaust tube 5.

The ring-shaped shoulder 12 which provides a seat for the end of the diverting tube 6 is arranged a spaced distance from the bottom part 2 of the casing 1. The plurality of recesses in the end of the diverting tube with the shoulder 12 form a plurality of radially oriented passages 7'. A relatively deep annularly shaped pocket 8' is formed below the passages 7' to collect the tobacco sauce. As the passages 7' are spaced from the bottom part 2 the tobacco sauce flow to the passages 7' is prevented and thus clogging is avoided.

The passage 9 includes a narrow portion 9' between the exhaust tube 5 and the diverting tube 6 provided by the tapered connecting part 12' near the foot part 5'. The filtration of the smoke occurs when the tobacco sauce is deposited in the annular pocket 8', and the smoke then passes through the fine passages 7', passage 9 and the exhaust tube 5 to the final exit, all without clogging the passages. Free passage of the smoke is assured and sufficient space for the tobacco sauce is provided. Simultaneously the tobacco smoke is additionally filtered through the self-produced tobacco sauce.

A condensation-distillation process takes place as follows: The heated tobacco smoke passes with considerable speed through passage 7 and heats the thin wall of the diverting tube 6 resulting in distillation. The exhaust tube 5, being not in contact with the diverting tube 6, is relatively little affected by this heating. Consequently, condensation primarily in the narrow part 9' and secondarily in the enlarged passage 9 takes place.

The passages 7' combined with the narrow part 9' effect a considerable compression of the tobacco smoke whereby the annular pocket 8' is in a positive way balancing the fast flow of the smoke stream. According to practical experience, this is very important. The annular pocket 8' is critical for a normal draw resistance with simultaneously high filtering action.

While the invention has been described in detail with respect to a now preferred example and embodiment of the invention it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefore, to cover all such changes and modifications in the appended claims.

Claims

Having thus described our invention, we claim:

1. A filter structure for use with cigars and cigarettes comprising:

a. a first member comprising a cylindrical casing, an internal coaxially positioned exhaust tube and an annular closure joining one end of said casing to one end of said exhaust tube, both ends of said exhaust tube being open and the end opposite said one end of said casing being open, the axial length of said casing being greater than the axial length of said exhaust tube and including a portion adapted to receive the end of a cigar or cigarette and support said cigar or cigarette axially with respect to said cylindrical casing,

b. said exhaust tube including an annular shoulder extending radially therefrom transverse to the axis of the exhaust tube, the perimeter thereof being spaced from the interior surface of said casing, said shoulder being a spaced distance from said annular closure forming an annular pocket defined by said shoulder, closure and casing,

c. a second member comprising a diverting tube closed at one end and open at the opposite end and having a length greater than the distance between said shoulder and the end of said exhaust tube opposite said one end, said diverting tube being positioned coaxially a spaced distance from said casing and said exhaust tube and including a plurality of inwardly projecting ribs contacting said exhaust tube to maintain said second member in position, said opposite end of said diverting tube contacting said shoulder and said closed end of said diverting tube being a spaced distance from the opposite end of said exhaust tube,

d. said diverting tube having a plurality of recesses substantially equally spaced about the opposite end thereof which with said shoulder form a plurality of fine radially oriented passages, and

e. an annular tapered portion about said exhaust tube and extending axially from said shoulder to a position a relatively short axial distance beyond said passages,

f. whereby initially hot smoke is directed sequentially through an outer annular passage defined by said casing and diverting tube, through said fine passages, through an intermediate passage defined by said diverting tube and exhaust tube, the intermediate passage being narrower between said fine passages and annular tapered portion, and through said exhaust tube; said diverting tube being heated by said smoke while said exhaust tube remains cooler resulting in distillation of said smoke in said outer passage with accumulation of tar in said annular pocket and subsequent condensation of said smoke in said intermediate passage.