US 2625995 A
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Jan. 20, 1953 D. J. RUST ETAL 2,625,995
CAM-ACTING TENSION DEVICE FOR FRAMELESS WINDOW SCREENS Filed April 30 1951 2 SHEETSSHEET l mvr-znrons David J: Rusi JackJiJensen BY MIT Jan. 20, 1953 D. J. RUST ET AL 2,625,995
CAM-ACTING TENSION DEVICE FOR FRAMELESS WINDOW SCREENS Filed April 50, 1951 2 Sl-lEETS-SHEET 2 Fig.2
z 13 15 El? 1 l6 14 paw-A5222" Jack J.Jensen BY Mil ATTORII EYS Patented Jan. 20, 1953 CAM-ACTING TENSION David Jordan Rust and Leandro, Califl, assignors DEVICE FOR FRAMELESS WINDOW SCREENS Jack H. Jensen, San to Ry-Lock Company,
Ltd., San Leandro, Calif., a corporation of California 2 Claims.
This invention pertains generally to improvements in frameless window screens.
In particular the invention relates to, and it is an object to provide, a novel device for tensioning a frameless window screen.
Such tensioning device includes an initially upstanding cam lever pivotally mounted in connection with the window frame for downward swinging motion in a lateral direction; the cam of such lever being at its lower end portion and engaging in a channel fixed on the bottom cross bar of the screen, and said cam acting to forcefully lower the bottom cross bar and to thus tension the screen upon the cam lever being so swung.
As the cam has a rotary motion when the cam lever is swung between an upstanding released position and a lowered screen tensioning position, with such motion in a laterally outward direction at the lower, channel engaging edge, there is a tendency for said cam to undesirably shift the channel and attached bottom cross bar in a corresponding lateral direction with possible improper positioning of the screen under tension in the window opening.
It is therefore an important object of the invention to provide a novel cam and channel assembly which is operative to impart the desired tension to the screen, but also acts in a manner to prevent outward lateral displacement of the channel and bottom cross bar by rotary motion of the channel engaging cam.
Another object of the invention is to provide a tensioning device, as in the preceding paragraph, wherein the tendency of the channel and bottom cross bar to displace laterally in an outward direction is counteracted by inclining the channel upwardly in the opposite direction.
It is also an object of the invention to provide a cam-acting tension device for frameless window screens which is designed for ease and economy of manufacture.
Still another object of the invention is to provide a practical and reliable tensioning device for irameless window screens, and one which will be exceedingly effective for the purpose for which it is designed.
These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal oi the following specification and claims.
In the drawings:
Fig. 1 is a fragmentary rear elevation of a frameless window screen showing a pair of the tensioning devices as used in connection therewith; the cam lever of the right-hand device be ing in its upstanding released position, while the cam lever of the left-hand device is in its lowered screen tensioning position.
Fig. 2 is a cross section on line 2-2 of Fig. l, but with the cam lever raised.
Fig. 3 isa cross section on line 3-3 of Fig. 1.
Referring now more particularly to the characters of reference on the drawings, the frameless window screen is here shown as disposed in a window frame, indicated generally at l, which frame includes, at opposite sides 2, the usual vertical blind stops it. The sill is indicated at i.
The irameless window screen is of the type which includes a section of wire cloth 5 fitted with a bottom cross bar 6 and a top cross bar (not shown) the latter being secured to the header of the window frame I by suitable means.
The bottom cross bar 6 includes a vertically adjustable U-shaped bottom strip 1 whose purpose is to provide a full closure between the bottom cross bar 5 and the top of the sill G.
The section of Wire cloth 5 is normally maintained under tension or taut by means of tensioning devices, indicated generally at 8; there being a pair of said devices, each working between one of the blind stops 3 and the corresponding end portion of the bottom cross bar 5.
As the tensioning devices 8 are of identical construction, except for being right and left hand, a description of one will sufiice for both.
Each tensioning device 8 comprises an elongated mounting strip 9 secured in fixed relation to the back side of the bottom cross bar 6 above the bottom strip 1; such mounting strip 9 including, in integral relation, an upwardly opening catch channel It which is disposed closely adjacent, but terminates short of, the correspond ing end of the bottom cross bar 6, whereby said catch channel does not engage the related blind stop 3.
The catch channel H3 is disposed at an upward incline from its laterally outermost end; the purpose of this inclination being hereinafter described.
An integral deflector tongue H extends at an outward and downward incline from the rear upper edge of the catch channel it, while a finger pull I2 projects rearwardly and upwardly from the mounting strip 9 laterally inwardly of said catch channel Iii.
A bracket unit, indicated generally at I3, and which is described in detail in my copending application, Serial No. 223,763, filed April 30, 1951, is secured to the adjacent side of the corresponding blind stop 3 directly beyond but mainly above the catch channel I 0; said bracket unit including a vertically adjustable attachment plate I 4 affixed to the blind stop 3 by a headed screw I5 which works through a vertical slot I6 in said plate I4,
An integral bracket plate I1 projects at a rightangle to the attachment plate I4 in a horizontal, laterally inward direction, and serves as the mount for a flat cam lever, indicated at I8.
At its lower end pivoted, as at I 9, in face to face engagementwith the bracket plate IT, for swinging between. an
upstanding released position, asatl the right in,
Fig. 1, and a lowered screen tensioningposition as at the left in such figure. At the end portion opposite the pivot I9 the cam lever It includes a finger tab 20 to facilitate manipulation of said lever.
The pivoted lower end portion of the lever I8 forms. an eccentric rotary c am, indicatedv at 2;I; this being accomplished by making the distance between the pivot I9 andthe rounded or arcuate initially lower edge 22 of theleven less than the distance between such pivot and the. initially laterally inner straight edge 23. ofthe lever I8.
Thus, when the lever I 8'is swung downward from its upstanding position to a substantially horizontal position, the cam 2|, Working in the catch channel I .ILurges the latter-together with the bottom cross bar 6-downwardly, forcefully efiectively tensioning the screen. In. its lowered, screen tensioning positionythe lever I8 passes dead-centerwith respect, to the cam shape-and and is thus. in efiect rleasably latched.
Upon the cam lever I8 being swung from its upstandingreleasedposition to its lowered screen tensionin -position, the cam 2I turns in a laterallyoutward directionat the bottom; i. e. below the pivot IS. The result ista tendency of the partturning or. rotating cam toshift the catch channel I0 and the bottoms cross bar 6 likewise in a laterally outward direction; there normally being some end play between the bottom cross bar 6 and opposite sides of the window frame I. It is undesirable that such displacement of the bottom cross bar 6, occur, as thismisalines the screen in thewindow frame I and prevents proper tensioning thereon by the transversely spaced tensioning devices 8.
It isjtherefore necessary that such tendency of ottomv cross ba 8 o displac n a l ally outward direction be counteracted, and this is accomplished by incliningeach catch channel It in the manner heretofore described. With the catch channel ID inclined upwardly in a lateral- 1y. inwa directi n. opposed, fo ce i od ce when the cam. His part-rotated, which force counter actsfthe, tendency of the cross bar 6 to sp ac i a d a ra ly ut r g n: T e expedient employed for the purpose is simple,
7 but nevertheless is most effective to accomplish thedesired end; to-wit, the maintenance of the frameless window screen in proper alinement in the window frame I when the tensioning devices 8 are manipulated to their screen tensioning positions, V
The finger pull [2 is used to initially draw the portion the camlever I8 isv 4 bottom cross bar 6 against the blind stops 3, whence the lower or cam end of the lever I8 engages the deflector tongue II and easily snapengages in catch channel I0.
From the foregoing description it will be readily seen that there has been. produced such a device as substantially fulfillsthe objects of? the invention, as set forth herein.
While this specification sets forth in detail the present and preferred construction of the device, still in .practicesuch deviations therefrom may be resorted toas do not form a departure from the spirit of the invention, as defined by the appended V Havingthus described the invention, the following is claimed; as new and useful, and upon which Letters Batent are desired:
1'. In a tensioning device for a frameless window screen having a bottom cross bar extending between opposite sides of a window frame; a cam lever. pivoted inconnee on with the window frame at one side thereof-an bar, the cam lever b 'ng' swingable downwardly from an upstandir' g,rv raised position inia direction parallel to the screenand to a lowered screen tensioning position, an upwardlyfacing element fixed on the bottom cross bar belowthe lever; the
lower end ortion of the lever being a rotary cam abutting said element, said cam, turning at the bottom edge in I a laterally; outward direction and simultaneously thrusting downwardly upon swinging of the lever, and said element being inclined upwardly in arropposite direction whereby to counteract the tendency of the turning cam to displace said element and the cross bar in said laterally outward direction.
2. In a tensioning device for a frameless window screenhaving. a. bottom, cross bar extending between Opposite sides era window frame; a cam lever pivotedin connection with thewindow frame at one side thereof and adjacent the bottom. cross bar, the cam lever being swingable downwardly fromanupstanding released position to a lowered screentensioning position in a direction parallel to the screen, and, an upwardly opening longitudinal, channel, fixed on the bottom cross bar below thevlev'en the lower end, portion of the lever being a rotary cam engaged in the channel, said cam turning at the bottom edge in a laterally outward direction and simultaneously thrusting downwardly upon swinging of the lever, and said channel being inclined upwardly in an opposite direction whereby to counteract the tendency of the turning cam to displace the said channel and the cross bar in said laterally outward direction.
DAVID JORDAN RUST.
JACK H'. JENSEN.
' REFERENCES cIrE The following references are of record in the file of this patent:
UNITED STATES, PATENTS Number Name Date 876,822 Maxwell Jan. 14, 1908 2,021,068 Kammerer Nov. 12, 1935 2,146,251 Dominick Feb. 7, 1939 d adjacent the b'o omvqr s.