US1938800A - Window ventilator and silencer - Google Patents

Description

Dec. 12, 1933. R. B. BOURNE V 1,933,800

WINDOW VENTILATOR AND SILENCER Filed March 18, 1931 2 Sheets-Sheet l INVENTOR. Rom/v0 B. 500R -15 Y B W 2 M A TORXEYS.

Dec. 12, 1933. R. BJBOURNE WINDOW VENTILATOR AND SILENCER Filed March 18, 1931 2 Sheets-Sheet 2 INVENTOR. Rom/v0 B. BlN/RNE M TTORNEYS.

Patented necyiz, 1933 This invention relates to devices for ventilating rooms through a window opening and having means for excluding street and other noises which would otherwise be admitted to the room.

In devices of this character, the size of the opening is an important factor. One of the problems presented is that of handling a maximum amount of air without turbulence while at the same time providing in the ,air passageways sound attenuating means effective to prevent sounds of .even very lowfrequencies from entering the room. The motor andfan must be capable, of moving a relatively large'volume of air without themselves creating suflicient noise to be audible within the room. The attenuating means must perform, its function with minimum obstruction to the passage of the air. In-general it is the object of the present invention to secure a more economical attenuation of street noises, particularly those of low frequencies,- in other words, to secure maximum noise elimination with a minimum sacrifice of ventilating efficiency. The attenuation of sound waves by means of acousticfriction falls off as the frequency is lowered; but in the structure of the present invention low frequency sounds, such as are. made by automobile exhausts, rumbling of trolley cars and the like, are sufllciently attenuated by providing relatively long passageways, so curved 'as to increase their sound attenuating ability. One feature of the present invention is the use of long, obstructionless and easy-curving passageways. More specific features of the invention will be apparent from the following specification and claims.

In the accompanying one embodiment of the invention:

Fig. 1 is aperspective view with parts cut away; 3

Fig. 2 is a top plan view with the cover plate removed; H Fig. 3 is a front elevation of the device; and

Fig. 4 is a sectional view substantially on line 4-4 of Fig. 1. j I

Referring to the drawings, 1 designates a flat substantially rectangular casing provided with straight vertical partitions 2, 3, 4 and 5. As best shown in Fig. 2, the end wall 6 of the casing is curved at 7 and partition 3 is connected thereto by a curved partition 8 forming a continuation of curve ,7. Similarly, opposite end wall 9 of the casing iscurved at 10, and a curved partition 11 connects portion 4 with the curved semi-circles with the free ends of partitions 2- drawings which illustrate portion 10.. Curved walls '1, 8 and 10, 11 form- 1,93s,s i

UNITED STATES PATENT OFFICE 1,938,800 wmnow. vrm' rma'roa AND SILENCER Roland B. Bourne, Hartford, Coma, assignor to The Maxim Silencer Company, Hartford, Conn., a corporation of Connecticut Application March 18,1931. Serial No. 523,541- Claims. (01. 913-94) and 5, respectively, as their centers. Partitions 2 and 5 are connected by a portion formed with two semicircular curves l4 and having their respective centers at the free ends of partitions 3 and 4. Point 16, at which curves 14 and 15- meet, is positioned centrally of passageway 1'] formed by partitions 3 and 4, and passageway 1'7 is twice the width of passages 18 and 19.

Passages 18 and 19 terminate respectively in openings 22 and 21 formed in the upper face of casing 1 at the inner corners thereof. Each opening 22 and 21 is provided with a shutter arrangement (see Fig. 4). comprising a frame 23 provided with a plurality of curved shutter vanes 24 pivoted to frame 23 by means of pins 25. The free ends of the shutter vanes are connected together for simultaneous movement'by a link 26. The movement and position of the shutters are controlled by a handle 2'7 positioned exteriorly of casing 1 and connected to one of the pins 25. It will be seen that with the shutter vanes fully open, as in the dotted-line position of Fig. 4, the air streamis directed upwardly and toward the window 28, thus substantially eliminating objectionable drafts when the device is blowing air into the room in cold weather. An intermediate position' of handle 2'7 will place the shutter vanes in such position that the air be directed inwardly away from the window should this condition be desirable, Upwardly curving members 29 direct the air current in the passages to theshuttered openings.

The inner surfaces of the casing and the faces of the partitions forming they air passages are covered, as indicated at 30,.-.with sound attenuating material, preferably a high grade acoustic felt covered with a perforated oil cloth.

A circular opening 31, defined by a short cylindrical ring 32, is formed in the outer wall 33 of I the casing 1 and opens centrally of passage 17. Ring 32 is of larger diameter than the vertical depth of casing 1 and is connected to the top and bottom faces of the casing by conical sections 34.

A reversible electric motor 36 is positioned in the casing between the conical sections 34 and is provided with a light weight propeller type fan 35 spring mounted on the motor shaft and positioned within ring 32. The motor 36 is carried on a stiff radial flat spring mounting system 37. This mounting satisfactorily takes care of all ex cept certain high frequency noises which pass through it, due probably to the fact that the vibration at these frequencies is not entirely torsional. This mounting, however, gives great rigidity in all other directions.

The slip stream from a propeller type fan is helical in nature but turbulence from this cause is prevented by the provision of double width passage 17 which forms a straight passageway immediately behind the fan ample to give the air stream an opportunity to become more or less uniform before entering any of the curved passages.

By the arrangement above described, the large volume of air entering passage 1'7 is diverted in equal shares to the long obstructionless easy curving passages 18 and 19, resulting in an eificiently silenced ventilator characterized by an exceptionally high air economy. Moreover, by this arrangement a compact symmetrical structure is obtained, and since the fan and motor are located outside the window any slight noise arising at this point, incidental to the moving of air or in the motor, is easily attenuated in the passageways.

The central switch assembly 40, by which the motor may be started, stopped or reversed, is supported on the inside wall 41 of the casing. The connection wires 42 leading from the switch to the motor are separated into two sections by the plug connection 43,thus permitting the motor to be withdrawn through opening 31 without disturbing the fixed wiring of the switches. A flexible cord conductor 44 extending from the switch assembly .outwardly of the casing is provided with a plug 45 for insertion in any convenient outlet.

The top and bottom of casing 1 are provided respectively with sealing strips 50 and 51, and the sides with brackets 52 and 53, whereby a weather and sound proof joint may be effected with the sash, sill and side frames of the window opening. What I claim is: v

1. A silencing ventilator for windows which comprises a casing adapted to be positioned between a window and its sill and having an opening outside the window, a straight sound attenuating passageway directed inwardly from said opening and two tortuous, unobstructed, easycurving, sound-attenuating passageways leading from said straight passageway and terminating in independent openings inside of the window. 2. A silencing ventilator for windows which comprises a casing adapted to be positioned beating passageway directed inwardly from said I of the casing opposite said first named opening.

tween a window and its sill and having an opening outside the window, a straight sound-attenuating passageway directed inwardly from said opening, and two tortuous, unobstructed, easycurving, sound-attenuating passageways leading from said straight passageway and terminating in independent openings inside of the windows, said straight passageway having a cross-sectional area equal to the combined cross-sectional areas of said two tortuous passageways.

3. A silencing ventilator for windows which comprises a casing adapted to be positioned between a window and its sill and having an opening outside the window, a straight sound attenuopening, two tortuous, unobstructed, easy-curving, sound-attenuating passageways leading from said straight passageway and terminating in independent openings inside of the window, and means in each of said last named openings to control the direction of the air currents issuing therefrom.

4. A silencing ventilator for windows which comprises a casing adapted to be positioned between a window and its sill and having an opening outside the window, a sound-attenuating passageway directed inwardly from, and in alignment with, said opening, a plurality of tortuous, unobstructed, easy-curving passageways leading from said first named passageway and terminating in independent openings inside 'of the window, said first named passageway having a crosssectional area substantially equal to the combined cross-sectional areas of said last named passages.

5. A silencing ventilator for windows which comprises a flat generally rectangular casing adapted to be placed horizontally between a window and its sill and having an opening positioned centrally of one edge face of the casing, a sound attenuating passageway formed within the casing and communicating at one end with said opening and at its other end with two diverging, tortuous, unobstructed, easy-curving passageways, said last named passageways terminating in independ ent openings formed in the upper face of the casing at the corners thereof adjacent the edge face ROLAND B. BOURNE.

Images