US3839950A

US3839950A - Hingeless ventilator

Info

Publication number: US3839950A
Application number: US00428063A
Authority: US
Inventors: T Kelly; D Callahan
Original assignee: Graham White Sales Corp
Current assignee: Graham White Manufacturing Co; Salem Vent International Inc
Priority date: 1973-12-26
Filing date: 1973-12-26
Publication date: 1974-10-08
Anticipated expiration: 1991-10-08
Also published as: FR2272344A1; JPS50117244A; JPS578386B2; DE2459899C2; BE823882A; GB1499336A; NL7416524A; ES433304A1; FR2272344B1; IT1026135B; SE7416047L; DE2459899A1; SE429524B

Abstract

A hingeless ventilator for an opening in a wall having a frame fixable to the wall about the opening, a foraminous plate unitary with the frame for screening the opening, and a closure member on a side of the wall and swingable against the frame at one or each side of the opening for opening and closing the opening. A spring rod on the opposite side of the wall and connected to the closure member by laterally spaced arms, rides on guides fixed to the frame for selectively positioning the closure member, while normally spaced means on the closure member and frame and interfitting during swinging of the closure member substantially fix the latter''s swinging axis or axes. The arms connecting the spring rod to the closure member are flat and extend through and ride in slots in the screen plate and are so shaped as substantially to fill the slots over their range of relative movement. A locating rib outstanding from the foraminous plate adjacent sides thereof and engaging the inner face of the closure member, either directly or through a sealing gasket thereon, positions the closure member during the initial portion of its swing for later engagement of the interfitting means.

Description

NH Oct. 8, 1974 United States Patent [191 Kelly et al.

[ HINGELESS VENTILATOR a frame fixable to the wall about the opening, a foram- [75] Inventors; Timothy Keny, Salem; David T. inous plate unitary with the frame for screening thlei e wa opening, and a closure member on a side of th Callahan, Lynchburg, both of Va.

and swingable against the frame at one or each side of the opening for opening and closing the opening. A spring rod on the opposite side of the wall and connected to the closure member by laterally spaced arms, rides on guides fixed to the frame for selectively positioning the closure member, while normally h 7 www m,6fl mma w n GSM4 0. e

o e m N. S e D. S p A FA M MP 7 2 2 .l. l.

spaced means on the closure member and frame and 52 C interfitting during swinging of the closure member 1 S I 98/2 98/2 18 substantially fix the latter s swinging axis or axes. The g rod to the closure member arms connecting the sprin are flat and extend through and ride in slots in the screen plate and are so sha [51] Int. B60h l/26 [58] Field of Search......................... 98/2, 2.16, 2.18

ped as substantially to fill [56] References Cited the slots over their range of relative movement. A locating rib outstanding from the foraminous cent sides thereof and en 8 g gf .fih n n 0 d .n n a m m o s d m t w a a w am a U 6 n n m m e n T. I em 6 a r ul t m gyl. 0 .m cf g closure member, either directl gasket thereon, positions the the initial portion of its swin the interfitting means.

Primary Examiner-William E. Wayner Assistant Examiner-Peter D. Ferguson Attorney, Agent, or Firm-Wilmer Mechlin ABSTRACT A hingeless ventilator for an opening in a wall having 11 Claims, 11 Drawing Figures n l s e 50000 00000 W OOOOO... 00000 W 00 0 00000 m o 0 00000 0000 w m ww% 000 CO 5 w0000 o0000 t t 00000 00000 n w 0000 00000 4 wwm wwwww L t m 00 m 4 L m 00000- 00000 m 2 W. 00000 00000 m 00009-00000 m w v/ oooqow ooo W n It! M u u 3 60000 0000 w 00000- 0000 V 9 8 3 00000, 00000 f OOOOOF OOOOO 2 v a 00000.. 0000 \T 000000 0000 H n H. 00000000000 l W 000000000001 m. 00000000000 m 000000 0000 n b W 00000 0 0000 J o n m 00000000000 t n o m 00000o00000 1 M 00000 0000 t u n m 10000900009 n w .1 z If: a El n 11 t IIINGELESS VENTILATOR BACKGROUND OF THE INVENTION Heretofore, numerous types of ventilators have been proposed for ventilating a cab or other driver compartment of a self-propelled land vehicle. Particularly in truck and tractor cab installations the need is for a ventilator adapted alternately to draw air into and exhaust air from the cab. A type of ventilator specifically designed to fill this need is a two-way hingeless ventilator such as disclosed in Kelly, et al U.S. Pat. Nos. 3,102,464 and 3,358,576. As in these patents, the ventilators of this type have a frame mountable on and bounding an opening in a wall of a cab or other enclosure and a closure member outside the wall and swingable against the frame on either side of the opening. The closure member is held against the frame and in any selected position, suitably by a spring rod connected for swinging in unison to the closure member and riding at opposite ends on fixed guides on the opposite side of the wall and instanding from the frame. In the prior pats on two-way hingeless ventilators a flange out-turned from the frame bounds the opening and the closure member in closed position covers the frame flange and has an in-turned marginal flange surrounding and overlapping the frame flange and engagable with the latter at either side of the opening for substantially fixing the axis about which the closure member swings in either direction.

In U.S. Pat. No. 3,358,576 it was recognized that the opening in the frame should be screened to prevent entry of bugs or other foreign matter in the forwardly open position of the closure member and that the screening would automatically be cleaned of such matter by the airflow reversal when the closure member was opened toward the rear. The solution disclosed in the patent is the use of screen sections mounted in brackets on the frame with slots in or at ends of the screen to accommodate arms extending therethrough for connecting the spring rod to the closure member for swinging in unison therewith and resilient flaps at both sides of each slot for sealing the slots over the range of swinging of the closure member. Also directed to a two-way hingeless ventilator, the present invention is particularly concerned with an improved solution to the problem of screening an opening in the frame.

SUMMARY OF THE INVENTION The primary object of the present invention is to provide an improved hingeless ventilator, having a frame and closure member, wherein a foraminous plate unitary with the frame not only screens an air opening in but also strengthens the frame.

Another object of the invention is to provide a two way hingeless ventilator having a frame and closure member, wherein an air opening in the frame is screened by a foraminous plate unitary with the frame and a spring rod for holding the closure member in selected position is connected to the closure member by flat arms spaced longitudinally of the closure member and having bases fixed to and extending substantially across the closure member, and the connecting arms extend through slots in the foraminous plate and are so shaped as substantially to close their slots over the range of movement of the closure member, whereby the arms can be thinner and the slots narrower than heretofore possible and the noise of the air passing through the opening is very considerably reduced.

An additional object of the invention is to provide a two-way hingeless ventilator having a frame and closure member, in which an air opening is screened by a foraminous plate unitary with and offset outwardly from a mounting flange of the frame and connected thereto by a web bounding the opening, the swinging axis of the closure member on either side of the opening is substantially fixed after initial opening by engagement of interfittable elements on the closure member and frame, and means on the frame and either directly or indirectly engaging an inner face of the closure member restrain the closure member in and adjacent closed position against lateral displacement relative to the frame.

A further object of the invention is to provide a twoway hingeless ventilator in which a spring rod for holding a closure member in selected position is connected adjacent opposite ends to the closure member by a bail fixed to the closure member and the rod is deflected for tensioning toward the closure member by means on the bail.

Other objects and advantages of the invention will appear hereinafter in the detailed description, be particularly pointed out in the appended claims and be illustrated in the accompanying drawings, in which:

FIGURE DESCRIPTION FIG. 1 is an inner plan view of an embodiment of the improved hingeless ventilator of the present invention showing the ventilator mounted in an apertured wall.

FIG. 2 is a longitudinal sectional view of the ventilator of FIG. I removed from the wall and taken along lines 2-2 of that figure.

FIG. 3 is a transverse sectional view taken along lines 3-3 of FIG. 1.

FIG. 4 is a transverse sectional view taken along lines 4-4 of FIG. 1.

FIG. 5 is an end elevational view taken from lines 5-5 of FIG. 1 with the closure member in open position.

FIG. 6 is a fragmentary transverse sectional view on the section of FIG. 4 but an enlarged scale showing the action of the positioning means during the initial opening movement of the closure member.

FIG. 7 is an inner plan view of another embodiment of the improved ventilator.

FIG. 8 is a longitudinal sectional view taken along lines 88 of FIG. 7.

FIG. 9 is an end elevational view taken from lines 9-9 of FIG. 1 with the closure member shown in partly open position.

FIG. 10 is a fragmentary transverse sectional view on a larger scale taken along lines 10-10 of FIG. 7, and

FIG. 11 is a fragmentary transverse sectional view on the scale of FIG. 10 taken along lines 11-11 of FIG. 7.

DETAILED DESCRIPTION Referring now in detail to the drawings in which like reference characters designate like parts, the improved hingeless ventilator of the present invention, while applicable for controlling the flow of air into an enclosure, is designed primarily for application a two-way ventilator to a cab or other enclosure of a vehicle for directing air into or from the enclosure while the vehicle is in motion, and will be so described as exemplary of the invention.

In the preferred two-way form illustrated in the accompanying drawings, the ventilator of the present invention is similar to those of Kelly, et al. U.S. Pats. Nos. 3,102,464 and 3,558,576 in having a frame 1 fixable or securable to a suitably apertured exterior wall 2 of a vehicle cab or other enclosure (not otherwise shown) and having a generally rectangular central opening 3 opening through the wall, a closure member, cover or door 4 seatable against an outer side of and swingable on the frame for opening and closing the opening, spaced guides 5 fixed to and instanding from an inner side of the frame at opposite ends of the opening, and a guide rod 6 connected to the closure member and having ends riding on the guides for holding the closure member assembled and in any selected position relative to the frame.

As in the hingeless ventilators of the above and other Kelly and Kelly, et al. patents, the frame 1 has a mounting or base flange 7 attached, fixed or secured, when installed, to the inside of the vehicle wall 2 about the aperture 8 therein and terminated or bounded inwardly by an out-turned lip 9 outstanding from and substantially normal to and unitary or integral with the mounting flange and laterally surrounding or bounding the frame opening 3. The closure member 4 is of the same generally rectangular shape as the opening 3 and has a suitably flat body or main part 10 of an area to fit over and close the frame opening in the closure members closed position. In the same closed position an intumed marginal flange or skirt 11 extending around the periphery of and instanding from and substantially normal to the body 10, surrounds and overlaps the lip 9 and is then or normally spaced from both the lip and the mounting flange 7 so as not to interfere with closing of the opening 3. When closed, the closure member preferably seals the opening 3 weatheror airtight, suitably by a sealing gasket 12 in the form of a generally rectangular band or sheet of rubber or like resilient material carried by and fixed as by bonding to and covering at least the peripheral portion of the members inner face 13. Whether a band or a sheet, the sealing gasket 12 extends from the skirt ll inwardly beyond and overlaps the fr'ames lip 9 in the closed position of the closure member 4.

In use for ventilating a cab or other compartment of a vehicle, the illustrated two-way ventilator is designed to be so installed or positioned that the closure member 4 can be opened longitudinally of the vehicle and alternately toward the latters front and rear. Thus, depending on the direction in which the closure member is opened, the ventilator, while the vehicle is moving, will direct air either into or from the compartment, the former by the pressure and the latter by the suction exerted by movement of the vehicle relative to ambient air. To prevent entry of bugs or other foreign solid matter or debris in the ventilators forwardly or front open condition, the opening 3 in the frame 1 is screened and, as opposed to the separate wire screening of Kelly, et al. U.S. Pat. No. 3,358,576, by a screen 14 unitary or integral with the mounting flange 7 and forming an integral part of the frame 1. The preferred screen 14 is a flat foraminous or perforated plate offset outwardly from the mounting flange 7 and peripherally connected or joined thereto through the outstanding lip or connecting web 9. Disposed parallel to the mounting flange 7 or at least the flat portion thereof adjacent the connecting lip or web 9, the screen plate 14 suitably has holes or perforations 15 arranged in longitudinally and transversely extending rows, with each hole of a size or diameter to pass air while substantially obstructing or inhibiting passage of bugs or other foreign solid matter.

The one-piece or unitary frame or frame assembly 1, including the mounting flange 7, connecting lip 9 and screen plate 14, while otherwise formable, is particularly adapted to be formed by stamping from a sheet of suitable metal in a single operation in which the frame is given the desired shape and the holes 15 are punched in the desired arrangement through the screen plate. Offset outwardly from and peripherally connected by the lip or web 9 to the mounting flange 7, the screen plate 14 additionally acts as a stiffening or reinforcing member, the presence of which rigidifies the frame and enables it, relative to previous ventilator frames, to be made of thinner sheet steel or even aluminum, without sacrificing strength.

As in the prior Kelly and Kelly, et al., patents, the axis about which the closure member 4 swings at either side of the opening 3, is substantially fixed by the interfit or interengagement of parts of the closure member 4 and frame 1, suitably the side portions of the lip 9 of the frame and skirt 11 of the closure member at corresponding sides of the opening. Over most of the range of swinging of the closure member relative to the frame at one side of the opening 3, the side portion of the skirt at the opposite side of the opening, under the tensile or pulling force of the spring rod 6, engages and acts against the adjoining side portion of the lip and seats or is received in or adjacent the bend at that side between the lip and the mounting flange 7 for substantially fixing the axis about which the closure member swings. By contrast, when the closure member is in closed or normal position, the skirt 11 should be spaced laterally from the lip 9 to prevent interference with closing of the closure member. With such normal spacing of the skirt and lip there thus is a relatively small transition arc in the range of movement of the closure member adjacent closed position, as it initially moves from and. completes its return to that position, when the closure member is not restrained by the skirt and lip against lateral movement relative to the closure member.

Unless otherwise restrained, the closure member 4 can shift or move laterally relative to the frame 1 in the plane of the mounting flange 7 not only during the transition period but also in closed position, with consequent possible jamming and impairment of the ventilators opening action. Were the outer end of the lip 9 exposed, as in Kelly, et al. U.S. Pat. No. 3,358,576, the restraint against lateral shifting could be imposed by the pressing of the outer edge of the lip into the resilient gasket 12 on the inner face 13 of the closure member. However, in the present ventilator, such coaction of the lip and gasket is precluded by the merging of the lip with the screen plate 14 at their juncture. Instead, the present ventilator depends for restraining relative shifting of the closure member 4 and frame 1 upon 10- cating or positioning rib or boss means outstanding or projecting or extending outwardly from the screen plate and indenting or pressing into and acting on the sealing gasket 12 and therethrough the inner face 13 of the closure member both in the latters normal or closed position and during the transition period.

Consistent with the preferred forming of the frame 1 by stamping, the preferred locating rib means are a continuous rib, boss or embossment l6 pressed, bumped or stamped into the frame and projecting outwardly or outstanding from and extending around the periphery of the screen plate 14 outside the perforations 15 and inside the lip 9. Suitably interposed between and merging on opposite sides with and integrally joining or connecting the screen plate 14 and lip 9, the preferred continuous locating rib 16 not only restrains the closure member 4 against lateral shifting from centered position relative to the frame, but by normally indenting or pressing into the sealing gasket 12 about the opening 3, also increases the efficiency of the sealing gasket as a weather seal in the closed position of the closure member. Over a plurality of suitably spaced individual locating ribs, the preferred continuous rib 16 is advantageous in eliminating any unrelieved stressing of the frame and can perform with the sealing gasket 12 its intended functions of restraining relative lateral movement and sealing against weather, even when, as illustrated, U-shaped in cross-section with an arcuately convex or rounded nose, apex or leading or gasket-presented edge 17 for minimal abrasion of the sealing. gasket.

Riding at opposite ends, either directly or through inwardly capped Nylatron or like anti-friction rollers 18, on the spaced guides or guide members 5 fixed to and instanding from the mounting flange 7 of the frame 1 at opposite ends of the opening 3, the spring guide or control rod 6 is connected adjacent opposite ends to the closure member 4 by arms 19 extending through the opening 3 and rectangular slots 20 in the end portions of the screen plate 14 beyond the perforations 15 therein. Disposed or extending transversely of the closure member 4, the preferred arms 19 are flat and generally pear-shaped or pyriform in outline or front or face elevation, with inturned feet or base flanges 21 fixed as by welding to the members inner face 13 and bodies 22 normal to and instanding from that face and their feet. Peripherally or marginally semi-ovoidal and flaring outwardly toward or tapering inwardly from the closure member, the bodies 22 at their relatively wide outer or foot-connected extremities and the feet 21 are of substantially the width of the perforated area of the screen plate 14 and extend substantially to the peripheral portion of the inner face 13 covered by the corresponding portion of the sealing gasket 12, while being contained laterally or transversely within the locating rib 16 in the closed position of the closure member. Each body 22 has counterpart, arcuately, preferably circularly convex opposite marginal edges, peripheries or sides 23, and each of which is substantially struck about or concentric with the swinging axis of the closure member 4 at the opposite side of the opening 3. Outwardly or away from the closure member 4 and beyond the bodies 22, the arms 19 terminate in suitably parallel-sided, round-ended heads or extensions 24 coplanar with their bodies and having apertures or slots 25 elongated longitudinally of the arms and normal to the closure member for receiving and accommodating any relative longitudinal play of the end portions of the guide rod 6.

Enabled by their wide-based pear-shape to be fixed to the inner face 13 of the closure member 4 adjacent opposite sides thereof, the connecting arms 19 not only stiffen the closure member over the areas covered by their feet 21 but are themselves of ample strength even when thinner than the connecting arms of previous hingeless ventilators. Additionally, with their marginal edges 23 each struck about the opposite swinging axis of the closure member, the width of the bodies 22 in the slots 20 or the plane of the screen plate 14 will be substantially uniform. over the range of angling or swinging of the closure member relative to the frame. With the areas of the slots 20 occupied by the bodies 22 correspondingly uniform over the range of relative movement of the closure member, it thus is both possible and preferred to hold the dimensions of the slots to tolerances relative to the width and thickness of the arms such that the open or unoccupied area of the slots at any point is of about the same width as each of 'the perforation 15. Consequently, when of the preferred shape and relative dimensions, the arms 19 and slots 20 are as effective as the perforated area of the screen plate 14 in screening the opening 3 and, by markedly reducing in the ventilators open position the slot areas left open by previous parallel-sided connecting arms, correspondingly smoothing the flow and reducing the noise of the air passing through the slots and eliminating any need for sealing flaps.

Alike in the foregoing respects, the ventilators of the embodiments of FIG. 1 and 7 are also alike in their spaced guides 5. Thus, in each embodiment the guides 5 fixed to the mounting flange 7 of the frame 1 at opposite ends of the opening 3 are bent or bowed intermediate their ends, conveniently by bending or stamping them from strip metal, and each presents on opposite sides for engagement by the adjoining end of the guide rod 6 arcuately and preferably cylindrically convex guide surfaces or guideways 26. As are the cylindrically convex sides 23 of the connecting arms 19, the preferred guide surfaces 26 on the sides of the guides or guide members 5 are each substantially concentric or coaxial with and struck about the swinging axis of the closure member 4 at the opposite side of the opening 3 so as to enable the tensile force applied to the closure member 4 by the spring rod 6 to be substantially uniform over the range of open positions of the ventilator. At their inner or adjoining extremities the guide surfaces 26 merge with and are connected or joined by an arcuately convex apex 27 of relatively short radius on which the adjoining end of the guide rod 6 rests or is positioned in the closure member's closed position.

Aside from somewhat differently configured mounting flanges 7 to suit particular installations, the differ ence between the embodiments of FIGS. 1 and 7 resides in the manner in which the tensile or pulling force of the spring rod 6 is applied to the closure member 4. In both embodiments the tensile force is generated by deflecting, bending or bowing the longitudinal or axial mid-portion of the guide rod 6 outwardly toward the closure member 4. In the embodiment of FIG. 1 the deflection is produced by a central tensioning or deflecting arm 28 centered on and fixed to the inner face 13 of the closure member 4. Otherwise suitably identical with the connecting arms 19 and identically related to its slot 29 in the screen plate 14, the tensioning arm 27 receives the guide rod 6 in a head slot 30 of an area to accommodate and pass the guide rod during assembly and disassembly but so spaced or offset outwardly toward the closure member 4 relative to the head slots 25 of the connecting arms 19 as to centrally bend, bow or deflect the guide rod toward the closure member by an amount predetermined to apply the desired tensile or pulling force to the closure member. For correct positioning of the guide rod 4 longitudinally relative to the tensioning arm 28, the former has at the center an annular notch or groove 31 for receiving or fitting the outer edge of the head slot 30 in the tensioning arm.

In the embodiment of FIG. 7, the connecting arms 19 are the only connections or links between the guide rod 6 and the closure member 4 but the head 24 of the arms are relatively longer than those of the first embodiment and suitably notched at their inner extremities or ends to receive the ends of the web portion 32 of a bail or handle 33. With out-turned legs 34 at opposite ends straddling and connected or fixed, as by riveting, to the heads 24 of the arms 19 inwardly of or beyond the head slots 25 therein, the bail 33 over its web portion 32, suitably is straight and substantially parallel to the guide rod 6 and longitudinally reinforced by a central rib 35 pressed or stamped therein. With the ribreinforced bail 33 providing a rigid backing or platform, the outward central deflection of the spring rod 6 in this second embodiment is produced by a conveniently V-shaped, arch or pressure bar 36 fixed to and extending longitudinally of the web portion 32. Outstanding or projecting outwardly from the outward or underside of the web portion 32, the pressure or deflecting bar 35 has as its outward extremity an apex or nose 37 engaging and acting on the spring rod 6, conveniently through the central annular positioning or locating groove or notch 31 in the rod, for deflecting r bending the rod outwardly toward the closure member 4 to the extent predetermined to provide the desired tensile force on the closure member 4.

As pointed out in Kelly U.S. Pat. No. 3,760,707, unless restraint against twisting relative to the guide members is imposed on the spring rod 6, an excessive twisting force applied toward one end of the rod, as by a kickof an operator, can force the ends of the rod to engage opposite sides of the guide members, in which case the ventilator will become inoperative and can even lose the closure member. In that patent the restraint against relative twisting is imposed by guiding the ends of the rod in double-bracketed guide members. However, in the present ventilator such guide members are unnecessary since the relatively large area constantly presented to the screen plate 14 by the wide connecting arms 19 and, if present, the tensioning arm 28 and the close fit of each arm in its slot or 29, effectively prevent twisting of the rod 6 relative to the guide members 5, thus rendering the ventilator proof against failure even when subjected in operation to excessive twisting forces.

Depending on the embodiment, the operator will use either the spring rod 6 or the bail 33 as a handle for swinging the closure member 4 to a selected position and, with the tensile force substantially uniform in the closure members open positions and preferably slightly greater in its closed position, the closure member will remain or be held in any selected position relative to the frame 1 until later swung or moved therefrom. Held against lateral movement relative to the frame in and adjacent closed position and therebetween by the interaction respectively of the locating rib l6 and sealing gasket 12 and of the adjoining side portions of the skirt 11 and lip 9, the closure member will always be positioned to open and close smoothly and provide an effective weather seal when closed, while the integral screen plate 14 on the frame 1 screens the opening 3 whenever the closure member is opened. Catching bugs and like debris on its outer surface when the closure member is opened toward the front, the screen plate will be automatically cleaned of any collected debris by the air outflowing from the compartment when the closure member is opened toward the rear.

From the above detailed description it will be apparent that there has been provided an improved hingeless ventilator, which by having a screen as an integral reinforcing part of a frame readily formable in one piece and connecting arms so configured as effectively to screen slots in the screen through which they extend, is relatively simple in construction, very rugged and economical to produce. It should be understood that the described and disclosed embodiment is merely exemplary of the invention and that all modifications are intended to be included that do not depart from the spirit of the invention and the scope of the appended claims.

Having described our invention, we claim:

1. A hingeless ventilator for ventilating a compartment through an opening in a wall thereof, comprising a unitary frame assembly attachable to said wall about said opening and having screening means integral therewith for screening said opening, a closure member swingable against a side of said frame for opening and closing said opening, guide means fixed to and instanding from an opposite side of said frame at opposite ends of said opening, means connected to and swingable with said closure member and riding on said guide means for holding said closure member in selected positions relative to said frame, and interacting means on said frame and closure member for restraining relative lateral movement therebetween over the range of movement of the closure member.

2. A hingeless ventilator according to claim 1, wherein the screening means is a perforated screen plate connected to and offset outwardly from a mounting flange of the frame, the holding means is a spring rod riding at ends on said guide means, and the interacting means include locating rib means on said frame and outstanding from said screen plate and acting on said closure member, and normally laterally spaced flange means on said frame and closure member and interfitting on partial opening of said closure member.

3. A hingeless ventilator according to claim 2, including a sealing gasket on an inner face of said closure member and coacting with said locating rib means for sealing about the opening in the closure members closed position and locating said closure member relative to the frame when the flange means are disengaged.

4. A hingeless ventilator according to claim 3, wherein the locating rib means are a continuous rib extending around the screen plate, and the flange means are a web outstanding from the frame about the opening between and connecting the screen plate and a mounting flange of the frame and a peripheral skirt instanding from the closure member and in the closed position thereof surrounding said web.

5. A hingeless ventilator according to claim 3, including longitudinally spaced arms fixed to the inner face of the closure member and instanding therefrom through slots in the screen plate and connected to opposite end portions of the spring rod, and the connecting arms have semi-ovoidal body portions riding in said slots over the range of movement of the closure member, said body portions being flat and having on opposite sides cylindrically convex surfaces each substantially concentric with a swinging axis of the closure member at an opposite side of the opening, and said slots being so dimensioned relative to said body portions as to be screened thereby in open positions of the closure member.

6. A hingeless ventilator according to claim 5, wherein the screen plate is perforated between the connecting arm slots therein by spaced perforations arranged in rows.

7. A closure member, according to claim 6, including a tensioning arm fixed to the closure member and connecting midportions thereof and the spring rod for defleeting the rod outwardly toward the closure member, and the tensioning arm has a body portion identical with the body portions of the connecting arms and identically related to a slot therefor in the spring plate.

8. A hingeless ventilator according to claim 6 including a bail fixed to and connecting the connecting arms inwardly of the spring rod, and means fixed to and outstanding from a web portion of the bail and acting on a mid-portion of the rod for tensioning the rod.

9. A hingeless ventilator according to claim 8, wherein the web portion of the bail is longitudinally reinforced by rib means integral therewith, and the tensioning means is an arch bar having at its inner extremity an apex fitting in an annular locating groove in the mid-portion of the rod.

10. A hingeless ventilator according to claim 1, including arms spaced longitudinally of and fixed to the closure member for connecting the connected means thereto, said arms instanding from the closure member through slots in the screening means and cooperating through said slots with the screening means for preventing twisting of the closure member relative to the frame assembly.

11. A hingeless ventilator according to claim 10, wherein areas of the arms presented in the slots to the screening means are substantially uniform over the range of swinging of the closure member relative to the frame assembly.

Claims

3. A hingeless ventilator according to claim 2, including a sealing gasket on an inner face of said closure member and coacting with said locating rib means for sealing about the opening in the closure member''s closed position and locating said closure member relative to the frame when the flange means are disengaged.

7. A closure member, according to claim 6, including a tensioning arm fixed to the closure member and connecting midportions thereof and the spring rod for deflecting the rod outwardly toward the closure member, and the tensioning arm has a body portion identical with the body portions of the connecting arms and identically related to a slot therefor in the spring plate.