US1016450A - Apparatus for destroying insects by means of electricity. - Google Patents

Description

. F. S. SMITH. APPARATUS FOR DESTROYING INSECTS BY MEANS OF ELECTRICITY.

APPLICATION FILED JAN.7. 1911.

1,016,450, Patented Feb. 6, 1912.

UNITED sTATES PATENT ()FFICE.

FRANKLIN S. SMITH, OF PHILADELPHIA, PENNSYLVANIA.

Specification of Letters Patent.

Patented Feb. 6, 1912.

V Application filed January 7, 1911. Serial No. 601,284.

To all 'wlwm t't may concern:

Be it known that I, FRANKLIN S. SMITH, a citizen of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful Apparatus for Destroying Insects by Means of Electricity, of which the following is a specification.

larvae and pupae, by means of electricity.

The apparatus includes means for the'production of an electric discharge to the action of which the said insects, etc., are subjected. The insects, their eggs, larvae or pupae, which it is particularly desired to destroy, are those which are destructive in various ways and which destroy articles of various kinds, and cause great loss of and injury to property.

In the apparatus illustrated herein, the discharges are caused by means of an alternating current of commercial or slightly higher high frequency'but it should be understood that a uni-directional current may be' employed.

Without attempting to enumerate all of the various articles and objects which may" be treated for the purpose of destroying the destructive insects which infest and may de-' stroy them, I may mention food products, such as cereals, prepared breakfast foods of the various kinds, dried fruits, flour, figs, etc.; tobacco, either in the leaf state or after it has been converted into some form of manufactured product, such as cigars and cigarettes; weari'ng apparel, such as furs, woolens, etc.; and books, papers, etc. As is well known, all of these various articles may be infested and are frequently not only injured but are actually'destroyed by the in-.

sects which are peculiar thereto.

There is a species of worm, more apt to be found in the warmer countries, commonlycalled the book worm, which attacksbooks, papers, etc., and causes great injury and damage thereto. a

Employment of my invention is not limit ed to the objects and articles designated above but it may be employed for the treatment of many others not named for the destruction of such insects as may infest them and cause their deterioration and destruct-ion.

In order that the apparatus embodying my invention, whatever its form of construction, may accomplish the best results, it is necessary generally that the objects and ar- My invention relates to apparatus or, means for destroying insects, their eggs,

ticles treated shall be free from metallic substances, though there are some cases which form an exception to this rule.

The objec s and articles to be treated are placed within and subjected to the action of present any metallic substances they would act as isolated capacities and would cause a condensation of the electrical current which passes through the objects or articles and thus prevent contact of the current with certain portions of the object or article being treated, with the result that the material located in proximity to such metallic substances would be unaflected and unacted upon by the discharge current through the articles or object being treated.

Cereals and breakfast foods generally may be treated in bulk or in the usual card board boxes in which they are sold but when treat ed in such boxes care must be taken to pre-' vent the presence of metal upon. the said boxes. Also cigars and cigarettes may be treated in bulk or in the boxes in which they are sold or marketed. The difliculty, however, in treating cigars and cigarettes in boxes as suggested is that such boxes usually are provided with decoration which includes a greater or less amount of metallic substance which would interfere with the successful operation of my invention and discovery inthe treatment of cigars in boxes; hence, cigars and cigarettes preferably should be treated in bulk and before being placed in the boxes in which they are marketed. In the treatment of clothing, care must be exercised to prevent the presence of metallic buttons because if such buttons are present and cause a concentration of the current at thepoints where they are located so as to prevent the action of the current upon the electrical discharges and if there should be they act as conductors, as already indicated,

portions of the material of the garment which are in proximity to and surround the said buttons.

In the employment of apparatus embodying my invention in the treatment of articles, such-as are above suggested, care must be exercised to prevent their oxidation and carbonization by the use of discharge sparks which are of too great capacity. The capacity of the sparks may be controlled in various ways and by experience it has been found that sparks may be produced'and employed in the carrying out and practicing of my invention which are of sufiicient capacity to destroy the insects, their eggs, larvae or pupze, which may be upon the articles treated but which will not cause injury to the articles themselves.

In the large number of experiments 'which I have heretofore carried out in the development of my invention, I have discovered that when carefully and intelligently employed and operated, my invention will destroy all of the insects in whatever stage of their development, whether as eggs, larvae, 'pupie or adults, which may infest or be present in or upon the articles or objects treated.

In the accompanying drawings I have illustrated a convenient embodiment of my invention but it will be understood and will be apparent from the description of the same which follows, that my invention may be embodied in other forms of construction.

In the drawings :Figure 1 is a top plan view of an apparatus embodying my invention; Fig. 2 is a sectional side elevation of the same; and Fig. 3 is an enlarged View on the line 3-3 of Fig. 1 showing more clearly a detail of construction.

Referring to the drawings :the numeral 1 designatesa source of alternating electric current, 2 a switch, and 3 a variable or adjustable resistance which is connected in series with the primary coils of a number of step-up transformers 5 which are connected in multiple with the source 1 of current.

The opposite ends of the secondary coils of the said transformers 5 are connected with the oppositely disposed electrodes 6 and 7. These electrodes are arranged in two rows, as is indicated in Fig. 1 of the drawings. The electrodes in the two upper rows are arranged in staggered relation with respect to each other, as is clearly shown in Fig. 1, while those in the two lower rows are arranged in staggered relation with respect to each other in the same manner. The number of transformers, electrodes, and arrangement of the latter may be varied as desired. Preferably,'though in some cases it may be found to be unnecessary, the electrodes should respectively 'terminate in a single point in order that all portions of the object or article being treated, whether in boxes or otherwise, may be subjected to the action of the discharge. It has been found that if electrodes of considerable length and respectively provided with a plurality of points are employed and articles are treated in boxes, it happens that the discharge takes place between points of opposing electrodes .which are nearest to alinement with a side of the said boxes along the said side so that the material in the boxes may not be acted upon.' In such cases, the insects or their eggs, larvae or pupae, which may be present in the articles and which it is desired to destroy, remain unharmed:

The electrodes 6 and 7 are supported in depressions or seats 10 and 11 formed in plates 12 and 13.0f non-conducting or insulating material, such as glass or porcelain. It will be understood that when the switch 2 is closed an electric discharge takes place between electrodes 6 and 7, such discharge consisting of well defined sparks and also of what is known as efiiuve, both of which are visibly apparent. The plates 12 and 13 are supported in any suitable manner, as for instance upon posts or standards 14 and 15. It will be observed that the electrodes 6 prioject a short distance below the lower 51 e ends of the electrodes 7 are located a short distance below the upper side of the plate 11.

20 designates a conveyer of suitable insulating or non-conducting material supof the surface of the plate 10 while the ported upon revoluble wheels 21 driven from any suitable source of power (not shown), by means of which articles being treated are conveyed into and across the space between the electrodes 6 and 7. The electrodes in the respective rows should be arranged close together and those in the respective plates upon which they are supported should be in staggered relation with respect to each other, as indicated in Fig. 1.

It is desirable that the electrodes should be arranged closely together and in staggered relation, as illustrated, in order that as an article is passed between the electrodes upon the conveyer 20 or by any other means supported intermediate or moved between and past the electrodes, all parts thereof are subjected to the action of the discharge; in other words, there should be no wide gaps in the line or curtain of discharge through which an article or portions of an article may be passed without being acted upon thereby.

As already indicated, the apparatus or machine illustrated herein produces low frequency electrical oscillations of commercial or slightly higher frequency. The said machine produces an alternating electric current but it will be understood by those skilled in the art relating to electrical machines that the current may be changed by known means from an alternating to a unidirectional current.

In order to operate the apparatus illus-, trated, the switch 2 should be closed and the! variable or adjustable resistance 3 adjusted! as desired. The capacity of the discharge spark may be controlled to some extent by adjusting the resistance 3 but it is principally dependent upon the transformers 5. In order to secure the best results, the distance between the electrodes 6 and the surface of the top portion of the conveyer 20 or other supporting means should be only slightly greater than the height or thickness of the objects or articles which are being treated in the apparatus. As the arti cles being treated are placed in position in the space between the electrodes they are acted upon by the electrical discharge which takes place between the said electrodes, the passage of which through the objects effects or causes the destruction and killing of the insects, their eggs, larvae or pupae, which may be present. It is my understanding and belief that the sparks are the portion of the discharge which is effective in destroying the insects, their eggs, larvae or pudae, and that the efiiuve does not destroythem.

In the treatment of tobacco in and by the apparatus herein described, whether it be in the form of cigars or in bundles or bales prior to being converted into a manufactured product, the leaves thereof should be placed in the machine or apparatus for treatment so that they extend substantially in parallel relation with the direction of the lines of discharge of the electric sparks between the opposing electrodes. If the tobacco is so placed that the lines of discharge take place transversely of the leaves, the said discharges are apt. to pass directly therethrough without spreading over their surfaces and in consequence are not likely to destroy all of the insects. It is also the case that if the discharge takes place transversely of the leaves of the latter it is likely thatthe latter would be carbonized. The voltage should also be adjusted or varied so as'to correspond with the capacity or conductivity of the article being treated. For instance, the voltage necessary to treat successfully a column of tobacco of a certain definite size and height should be less than that employed in the treatment of a column of the same size and height of some other substance of less conductivity, for instance, a cereal.

In the construction as illustrated, the electrodes are'so arranged that the discharge produced forms substantially a curtain so, that if an article or object is pass'ed'between the electrodes, every part thereof is subjected to the action of the discharge and all of the insects, their eggs, larvae or pupae, are

destroyed. It is to be understood, however, that my invention is not limited tothe specific arrangement of electrodes illustrated. I have discovered. that the said insects,

etc., are killed immediately by the action ofthe said sparks, and I have discovered also that the said sparks seek out the said insects, eggs, larvae or pupae, wherever they may be in the package and destroy them.

The broad subject matter of'invention disclosed herein and not claimed is claimed in my co-pending application filed January.

7th, 1911, Serial No. 601,283.

The term electrode or electrodes employed herein is not one of limitation but of description and includes any terminal, as for instance the ends of the secondary coil, from which electrical discharges take place.

Having thus described my invention, I claim 2-- 1. In an apparatus of the characterdescribed, the combination of a source of alternating electric current, transformers the primany coils of which are connected thereto,"

electrodes or terminals connected to the opposite ends of the secondary coils of said .transformers, the said electrodes or terminals being arranged in electrically independent pairs and in oppositely disposed groups and the electrodes or terminals in each group being situated in rows in staggered relation with respect to each other, and means consisting of non-conductive material for supporting articles or objects between the said electrodes or terminals whereby the electrical discharges between the said electrodes may pass through said articles and objects and destroy any insects, their eggs, larvae or pupae which may be therein'or thereon.

2. In apparatus of the character described, the combination of a source of elecpositely arranged electrodes connected to said transformers, the said electrodes being arranged in electrically independent pairs and each pair having connection with a different transformer, and means for supporting articles between said electrodes.

4. In apparatus of the character described, the combination of a source of alternating electric current, a plurality of transformers of small capacity, a plurality of electrodes in oppositely arranged groups having connection in electrically independas my invention, I have hereunto signed my entdpairs with said gransformers, this1 el lecname this 4th day of January, A. D. 1911.. tro es in eao group eing in staggere re a- T T tion with respect to each other, and means FRAI RLII SMITH 5 for supporting articles between said groups In the presence of of electrodes. GEO. H. WEIDNER,

In testimony that I claim the foregoing CARRIE E. KLEINFELDER.

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