US2158074A

US2158074A - Air circulating device

Info

Publication number: US2158074A
Application number: US78821A
Authority: US
Inventors: Francis C Kilb
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-05-09
Filing date: 1936-05-09
Publication date: 1939-05-16
Anticipated expiration: 1956-05-16

Description

May 16, 193.

F. C. KILB AIR CIRGULATING DEVICE 4 Sheets-#Sheet 1 Filed May 9, 1936 May 15, 1939' F. c. KILB AIR CIRCULATING DEVICE Fiied May 9, 1956 4 sheets-sheet 2 fa AT RM 0%/ n mc. m E /O V6 m/ May 1s, 1939. F, C KILB 2,158,074 l AlR CIRCLATING DEVICE Filed May 9, 1936 4 Sheets-Sheet 5 Ay AT RNEY Mayl 1s, 1939.

F. C. KILB AIR CIRCULATING DEVICE Filed May 9. 1936 4 Sheets-Sheety 4 AT ORNEY Patented May 1-6, 1939 UNITEDI STATES PATENT OFFICE AIR. CIRCULATING DEVICE Francis C. Kilb, Larchmont, N. Y.

Application May 9, 1936, Serial No. I78,821

13 Claims.

My invention relates to air circulating devices, and more particularly to devices of this character which eiect circulation of air in room spaces; such, for example, as a window-mounted ventilator having a fan or blower arranged therein and operating to introduce a stream of fresh air into the room space through an air outlet opening in the front of the ventilator casing.

It will be appreciated that, as devices of the above type are usually installed in spaces occupied by people, appearance and neatness are extremely important factors to be considered in their design. As the devices are operated by all types of individuals, dependability in operation is also important. Furthermore, low cost of manufacturing and assembling, and low cost and ease of servicing, are also necessary for the commercial success of the device.

Devices of this type are usually provided with louvers in their air outlet openings which serve to direct the air owing therefrom to desired portions of the room and/or serve to close the air outlet openings. The louvers should operate easily and simply and remain in any desired position: and they should not be mounted in the unit in such a manner as to produce a detrimental effect on the external appearance-of the unit; but, on the other hand, should be mounted in a manner to add to its external appearance. Here.- tofore, louvers have been pivoted directly to the sides defining the air outlet opening; however, the assembly of such a construction is of necessity a relatively long and tedious operation, and therefore is relatively expensive. It has also been proposed to pivotally mount the louvers in a separate frame and attach the frame to the casing; but structures of this type, heretofore known to me, are objectionable either because it is extremely p difficult to repeatedly position properly the louvers in the 'air outlet opening, or because timeconsuming and expensive operations are required inA properly positioning the frame with respect to such opening; and also because, after such a frame is mounted in the opening, it is still visible from the exterior of the device and therefore detracts materiallys from its appearance.

My invention has for a broad object to provide an air circulating device for use in room spaces, which is of improved construction and arrangement of parts.

Further and more specific objects of my invention are to provide eilicient lo-uver means for an air circulating device which can .be easily manufactured, assembled, and serviced, and at a low cost; which can be quickly and accurately posi.

tioned with respect to the air outlet opening; and one which, in its preferred form, presents a neat appearance from the exterior of the device.

Without imposing any limitation on the invention in its broader aspects, a still further object is to provide an improved form of louver construction for air circulating devices which can be readily adjusted todirect the air to different desired portions of the room and which is effectively retained at any desired adjusted position.

'Ihe invention consists in the novel construction and combination of parts, to be more fully described hereinafter, and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings, to be taken as a part of this speciiication, I have fully and clearly illustrated a preferred embodiment of my invention, in which drawings- Fig. l is a vertical transverse sectional View of a. window-mounted ventilator constructed in accordance with the present invention, the view being taken on the line I-I of Fig. 2;

Fig. 2 is a front elevation of the device shown in Fig. 1, drawn on a reduced scale; i

Fig. 3 is a perspective View showing the inside of a portion of the front cover of the ventilator casing with a unitary louver frame assembly removed from the cover to illustrate its construction and mode of assembly;

Fig. 4 is a fragmentary horizontal plan sectional View of thel front cover of the ventilator casing with the louver frame assembly mounted therein, the line of the section being indicated by the line -d of Fig. 2;

Fig. 5 is a perspective view of the unitary louver frame assembly showing the side thereof opposite to that shown in Fig. 3;

Fig. 5 is a perspective view of the louver frame shown in Fig. 5 with the louver plates omitted;

Fig. 7 is a detail assembly view showing the construction of the louver plates and the pivot rod therefor;

Fig. 8 is an enlarged detail assembly View showing more clearly the unitary link assembly for operating the louver plates in unison; and

Fig. 9 is a view similar to Fig. 6, but showing a modiiied form of louver frame.

In the accompanying drawings, I have shown my invention as incorporated in a window ventilator comprising a casing structure lil suitably supported by a window sill l I and arranged within the opening dened by a partially raised sash l2 and the sill H. The ventilator casing is arranged midway between Window jambs I3, as shown, and suitable filler blocks I4 serve to close sill II; a top wall 29 having a sealing engagement with the lower rail 2| of the window sash I 2, and having a louver-controlled air outlet 22 in the portion thereof extending into the room; and end walls 23. The outlet I6 extends for subsnantiauy' the full length ofthe front wan l5 and is divided in its center by a vertical strip 24 into

outlet openings

25 and 25a o1 similar size and shape. The inlet opening I8 extends preferably for the full length and height of the rear wall I1 and rigid louvers 26 are provided on the rear wall for preventing the entrance -into the ventilator of snow and rain. A suitable removable iilter 21 is arranged inside of the ventilator and is disposed across the inlet opening I8 to remove dust particles and the like from,I the incoming air.

For the purposes of initial assembly, and of removal, repair, and replacement, the casing i9 is divided preferably into two parts 39 and 3|. The part 39 is iixedly mounted in the Window opening and consists ofthe bottom wall I9, the rear wall I1, rear wall parts 32 of the end walls 23, and rear wall part 33 of the top wall 29, the latter being hinged at the back as indicated at 34 tol permit insertion and removal of the filter 21. The part 3| is, readily removable as a unit from the part 39 and comprises the front wall I5, front wall parts 35 of the end walls 23, and front wall part 36 of the top Wall 29. The part 3| may be appropriately referred to as the removable front cover unit and the part 39' as the ixedly mounted base unit.

A partition 31 extends longitudinally of the casing I9 for the full length and height thereof and divides the latter into a rear inlet chamber 38 communicating with the inlet I8 and an outlet chamber 39 communicating with the outlet I6 and outlet 22. .The partition 31 is provided in itsupper part with an opening 49 connecting thechambers 38 yand 39.

-Arranged within the inlet chamber .38 is a removably `mounted motor-driven blower unit 4| having an inlet 42 communicating with the inlet chambery 38 and an outlet 43 communicating withthe outlet chamber 39 through the opening 49 inthe partition 31. A suitable damper M extends lengthwise of the casing in the outlet chamber 39 and is pivotally supported at its upper end as indicated at-45. The damper in one position provides for the closing of oommunication between the inlet and

outlet chambers

38 and 39; and, when in another position, forms a part of a tortuous sound deadening passage 46 connecting the opening 49 and the outlets I6 and 22. Theopen position of the damper 44 is the position shown in Fig. i of the drawings.

As stated, the outlet I6 is divided by the strip 24 into the

openings

25 and 25a. FromI an examination of Figs. 2, 3 and 4, it will be seen that the opening 25 is dened by top and bottom edge portions 59 and 5I and by vertical'

side edge portions

52 and 53. Likewise, the opening 25a is dene'd by top and bottom edge portions 59a and 5Ia and by vertical

side edgel portions

52a and 53a. The

top edge portions

59 and 59a of the

openings

25 and 25a, respectively, are in the same horizontal plane. Likewise,v the bottom.l edge portions 5| and 5|a of the

openings

25 and 25a are in the same horizontal plane. The

edge portions

52, 53, 52a and 53a of the

openings

25 and 25a are arranged in parallel relation, as shown, with' the

edge portions

53 and 52a forming the vertical sides of the dividing strip 24.

In accordance with the present invention, I have provided an improved form of louver means which is carried by the front wall I 5 and forms a part of the removable cover unti 3|. The louver means is mounted in the

openings

25 and 25a forming the outlet I6. This louver means is preferably so constructed as to direct the air flowing from the casing I9 .to diierent desired `portions of the room, and also serves to close said outlet I6, and comprises a frame 55 preferably formed integral with the front wall I5, and a removable louver frame assembly 56 detachably secured to he inside of the wall I6.

From an examination of Fig. 3, it will be seen that the frame 55 comprises

sub-frames

51 and 51a bounding the outlet openings 25a respectively. 'Ihe sub-frame 51 comprises flanges 59 and69 extending inwardly from the top and bottom edge portions 59 and 5|, respectively, and anges 6I and 62 extending inwardly from the

side edge portions

52 and 53, respectively. lli'he

flanges

59, 69, 6| and 62 are formed integral with the front wall I5 of the casing and bound the outlet opening 25.

Likewise, the sub-frame 51a comprises inwardly extending top and bottom flanges 59a and 69a, and vertical side iianges 6Ia and 62a which are formed integral with the front of the casing and bound the outlet opening 25a. A plurality of series of inwardly

opening notches

63, 64, 63a and 64a are formed in the vertical side ilanges 6I, 62, 6|a and 62a fora purpose which will presently appear. 64a forming each series are in horizontal alinement. v

The louver frame assembly 56 is formed as a unit and is secured removably to the inside of the front wall I5 by siutable screws 65 threaded in openings in brackets 66 suitably fixed, for example by spot welding, to the front wall I5. The louver frame assembly 56 comprises a main frame 61 and louver plates 68 pivotally mounted in the main frame on horizontally-extending pivot rods 69.

rIn the construction shown in Figs. l, 3, 4, 5 and 6, the main framel 61 comprises a top member 19, a bottom member 1I in parallel spaced relation,

end members

12 and 13, and closely spaced intermediate members 14 and I5 connecting the mid portions of the top and bottom members 19 and 1I to thereby form a rigid rectangular structure. The top member 19 is provided with an outwardly-extending iiange 16 of predetermined width. Likewise, the bottom member 1I is provided with an outwardly extending ange 11 of the same predetermined width as the flange 16. The

end members

12 and 13 and intermediate'

members

14 and 15 are provided with outwardly-extending

anges

18, 19, 89 and 8|, respectively, and of the same predetermined width as the

flanges

16 and 11. The

flanges

16, 11, 18, 19, 89 and 8| are formed integral with and extend outwardly 4and 51a on the front wall of the casing, but

are slightly larger in dimensions.

As can be readily seen from an 4examination The

notches

63, 64, 63a and of Figs. 1 and 4, when the louver frame-assembly is in position against the inside of the front wall l5, the

sub-frames

82 and 82a embrace and t snugly the

sub-frames

51 and 51a, respectively. of the casing. In assembled position, the outermost edges of the

anges

18, 19, 89 and 8l preferably engage the inside surface of the front wall of the casing; and, as the ilanges are of the same predetermined width, they serve to assure a predetermined position of the louver frame assembly with respect to such front wall and the

openings

25 and 25a. As the flanges forming the sub-frames 82 and 82a. of the louver frame fit and positively engage the exterior surfaces oi the corresponding fianges forming the

subframes

51 and 51a on the casing, the louver frame is positively positioned with respect to the

outlet openings

25 and 25a and is prevented from displacement in directions parallel to the front of the casing and the plane of the

outlet openings

25 and 25a. The screws 65 passing through the

end members

12 and 13 and through screwthreaded openings in the brackets 85, serve to positively hold the louver frame assembly in position against the inside surface of the front wall i5.

As stated, the louver frame assembly 56 also comprises a plurality of louvers 68 pivotally mounted on rods 89, said louvers 58 being ar-` ranged in parallel relation to one another within each of

vthe sub-frames

82 and 82a, and the louvers of one sub-frame are arranged coaxial with corresponding louvers in the other subframe. Each of the pivot rods 69 extends horizontally through alined openings in the end vand intermediate flanges 18, 19, and 8| and passes through and is suitably secured to correspondingly positioned louvers in the sub-frames, so that corresponding louvers in the sub-frames move about the same axis and the louvers of each sub-frame move about parallel axes.

When the louver frame assembly is in place against the inside of the front wall I5, the louver` plates are disposed within the

sub-frames

51 and 51a adjacent the

openings

25 and 25a, with just enough clearance between the ends of the plates and the adjacent flanges to permit pivotal movement of the louvers. Suicient clearance is provided between the ends of the louver plates and the sides of the

sub-frames

82 and 82a to permit the location of the side anges of the

sub-frames

51 and 51a. between the ends of the louvers and the sides of the sub-frames, 82 and 82a. The alined notches 63, 84, 63a. and 84a receive the intervening portions of the pivot rods 69 so as to permit the proper positioning of the louvers and frame with respect to the

openings

25 and 25a.

Each of the louvers 68 is provided at its end adjacent the vertical dividing strip 24 with an y inwardly extending ange 85. The anges 85 of all of the louvers are connected together for operation in unison by a link assembly, indicated in general by the reference character 86 (see Fig. 8). The link `assembly comprises a pair of spaced side links 81 and 88 connected together by

cross pins

89 and 90, the latter being suitably spot welded tothe side links. 'The side links 81 and 88 are provided with outwardly-turned end portions 9| which are adapted to t within openings-provided in the outer end of the anges 85 of the top and bottom louvers of each of the sub'- Irames 82 and 82a. The cross pins 89 and 90 extend beyond the

links

81 and 88 and are adapted to t within openings provided in the outer portions of the anges 85 of the intermediate louvers of the sub-frames. g

An operating lever 93 extends through a slot 94 provided in the dividing strip 28 in the front wall of the casing, and is suitably pivoted on the intermediate portion of. one of the pivot rods 89, as can be seen from an examination of Fig. 5A The inner end of this operating lever is forked, as indicated at 95, and engages the connecting pin 89 of the link assembly 88. The opposite end of the operating lever is provided with a knurled portion 96 which can be grasped by the hand from the exterior of the casing for moving the link assembly up or down and, consequently, the louvers in either direction or to closed position.

An arcuate-shaped spring member 889 is arranged substantially concentric to the arc of movement of the forked end 85 of the operating lever 93 and engages the inner end of such lever. The ends of the spring member It@ are anchored by screws iti suitably threaded in cross-pieces |92 and i132 secured by spot welding to the intermediate members ll and 'i5 of the louver frame. The arcuate-shape spring member |99 is formed von its concave side with notches it, 85 and 'it in which the forked end 95 of the lever is adapted to fit. By reason of. this construction, the member i serves as a spring-pressed brake for the operating lever 93 to prevent accidental movement of the lever and louversyand when the forked end ts within one of the notches in the member |09, the lever is more rmly held. The notches are suitably positioned to afford'this extra precaution against accidental movement at the two extreme positions and at the mid or closed positions of the lever and louvers. In

Fig. 1 of the drawings, one extreme open posi-I tion is shown in full lines, and the closed position of the louvers and lever is shown in dotted f lines.

From the above, it will be readily seen that I have provided an air circulating device which is of improved construction and arrangement of parts. form of a separately assembled unit` having the louvers properly positioned and mounted therein previous to attachment to the casing, and having spacing anges of fixed dimensions which are constructed to embrace snuglyv cooperating flanges on the casing, and which engage positively the inside surface of the front wall of the casing; the

louvers may be at all times properly and quickly positioned with respect to their respective outlet openings and with a minimum requirement of time. As the inwardly extending flanges of the casing t within the outwardly extending flanges of the louver frame assembly, no sharp edges or rough surfaces can be seen from the front of the casing. Therefore, the outlet openings with the louvers properly positioned therein, present a neat and pleasing appearance. Furthermore, the particular mounting of the louvers in the frame with the operating link assembly, operating lever and arcuate-shape spring, provide a louver construction for air circulating devices which can be readily and easily adjusted to direct the air to diierent desired portions of the room or to close the opening and which effectively retain the louvers in any desired adjusted position.

In Fig. 9 of the drawings, I have shown a louver frame which is manufactured in a diferent' As the louver frame assembly is in the tion. The modified louver frame is indicated at l and comprises an integral one-piece unit, having sub-frames I Il and I l2 formed by flanges I I3 vwhich are stamped out of a single piece of metal.

The louver frame shown in Fig. 9 is formed of elements which function identically with the elements of the one shown in Fig. 6, the only difference being that the one shown in Fig. 6 is formed of angle pieces spot welded together, and the one shown in Fig. 9 is a single stamping. The construction of Fig. 9 may beless expensive than the construction previously described, should the units be made in sufdciently large quantities to j'ustify the initial cost of the dies for stamping.

What I claim and desire to secure by Letters Patent of the United States is:

1. An air circulating device for use in room spaces, comprising walls defining a casing; one wall of said casing having an air opening therein; flanges extending inwardly ofy the casing from the edges dening said opening; a louver frame arranged within said casing adjacent said opening and behind said flanges so that the frame is concealed by the anges; and louvers carried by said frame and extending across said opening for controlling the ow of air through said opening.

2. An air circulating device for use in room spaces, comprising a casing including a wall structure, one wall of which is provided with an opening; a louver frame arranged inside of said casing and adjacent the sides of said opening and including outwardly directed flanges engaging at their outer edges the inside surface of said one wall; louvers carried by said flanges andy extending across said opening; and flanges extending inwardly'of said casing from the defining edges of said opening and overlapping and concealing the anges of said louver frame.

3. An air circulating device for use in room lspaces, comprising a casing including a. wall structure, one Wall of which is provided with an opening; a louver frame arranged inside of said casing; louvers pivotally mounted at their ends to said frame and extending across said opening;

flanges extending inwardly from the dening edges of said opening and concealing said louver frame; said flanges having inwardly-openingv notches receiving the pivotal mountings for said louvers.

4. An air circulating device for use in room spaces, comprising a casing including awall structure,`one wall of which is provided with an opening; positioning flanges extending inwardly of the casing from the inside dening edgesof the.

opening; and a louver frame assembly arranged interiorly of said casing and having outwardly extending flanges engaging the surfaces of said casing flanges which are remote from the opening so as to position the louver frame assembly positively with respect to said opening.

5. An air circulating device for use in room spaces, comprising a casing including a wall structure, one wall of which is provided with an opening; flanges rigid with said wall and projecting inwardly into the casing from opposite edges of Y said opening; a unitary louver structure arranged within said casing and adjacent said opening and including a frame member conforming substantially to the contour of said opening; said frame member including opposite frame elements 1ocated respectively on the sides of said flanges which are remote from said opening; and louver plates pivoted in said frame elements and extendving across said opening; said louver frame having parts projecting outwardly therefrom into engagement with the interior surfaces of said wall.

6. An air circulating device for use in room spaces. comprising a casing including a wall strucwithin said casing and adjacent said opening and including a frame member conforming substantially to the contour of said opening; said frame member including opposite frame elements lo-,n cated respectively on the` sides of said flanges which are remote from said opening; and louver plates pivoted in said frame elements and extending across said opening; said louver frame having parts projecting outwardly therefrom into engagement with the interior surfaces of said wall.

and engaging at their inner side surfaces the surfaces of said flanges which are remote from said opening.

7. Anair circulating device for use in room spaces comprising walls defining a casing structure; one of said walls having an air opening 2o therein; frame means rigid with said casing and comprising positioning ange members extending interiorly of the 'casing from the inside edge portions of said opening and being disposed at opposite sides of the opening; and a louver frame assembly secured to the casing at the inside thereof and comprising a louver frame member similar in shape to said casing frame means and slightly larger in dimensions, and a plurality of louver plates pivotally mounted at their opposite 3u ends to the louver frame member; said louver frame member including outwardly extendingl portions receiving the pivotal mountings for the louver plates and being arranged at the outside of and engaging the sides of said ange members, :is

and abuttingv the inside surfaces of the casing.

8. An air circulatingfdevice for use in room spaces, comprising walls defining a casing structure; one of said wa'lls having an air opening therein; frame meansrigid with said casing and 4o comprising positioning flange members extending interiorly of the casing from the inside edge por# tions of said opening and being disposed at opposite sides or' the opening; and a louver frame assembly secured to the casing at the inside thereof and comprising a louver frame member similar in shape to said casing frame means and slightly'larger in dimensions, and a plurality of louver plates pivotally mounted at their opposite ends to the louver frame member; said louver frame member including outwardly extending portions receiving the pivotal mountings for the louver plates and being arranged at the outside of and, engaging the sides of said ange members.

9. An air circulating device for use in room v spaces, comprising walls dening a casing structure; one of said Walls having an air outlet opening therein having pairs of opposed sides; casing frame means comprising positioning flanges formed integral .with said one casing wall and 6|" extending interiorly of the casing from the in;- side edges of said opening, there being a flange at each side of the opening and extending for the full length thereof, and the anges being arranged in planes normal to the plane of the outlet opening; one pair of the oppositely disposed flanges having alined notches formed therein and opening inwardly of said casing; and a louver frame assembly secured to the 'casing at the inside thereof'and comprising a frame member similar 70 in shape to the casing frame means and slightly larger in dimensions, a plurality of louver plates, and means for pivotally mounting the plates at their opposite ends to the louver frame memben" said louver frame member including outwardly 'I6 extending portions arranged at the; opposite side of and engaging the sides of the casing flanges and having their outermost edges abutting the inside surfaces ofthe casing whereby the louver frame, with the louver plates mounted therein,

is positively positioned (in directions both lateral and normal to the plane of the outlet opening;

'l slightly larger thanI the aforementioned rectangular frames; said frame structure .being arranged at the inside of the casing with it outwardly extending flanges embracing and fitting snugly about the rectangular frames on the casing and having the outer edges of its outwardly extending iianges engaging the inside of the said pivotal mounting means comprising pivot casing to( properly position the louver frame l rods extending from the, ends of the louver plates through the alined notches in the casing frame ilanges and being secured at their outer ends to the outwardly extendlngportions of the louver w frame.

10. A n air circulating device for use in room spaces, comprising a casing including a wall having an air outlet opening; flanges extending interiorly of the casing from said wall and bounding said outlet opening to provide a frame rigid with the wall and at the inside ofthe opening; said flanges having a plurality of relatively deep inwardly opening notches vformedV thereinland disposed at opposite sides of the opening with each of the notches being in alinement with a corresponding notch on the opposite side of the sopening; 'a louver framehaving an opening of substantially the same configuration as said outlet opening and having slightly larger dimensions;

said louver frame including outwardly extending 1 anges formed rigid with the louver'irame and boundingthe opening therein; said louver frame iianges embracingand iltting snugly about the casing iianges and engaging at their outer edges `the inside surfaces of the casing; pivot rods ex- `tending across the openings and through said aimed notches and secured at their opposite" ends in the louver trame flanges; a plurality of louver plates arranged within the space defined by the casing flanges 'and vextending across such space from one side to the opposite side thereof and each plate being pivotally mounted on one of the pivot rods; and means for'securing the louver frame to the casing wall.

11. An air' circulgting device for useiln room spaces, comprising a casing having a pair of rectangular-shaped openings .oi substantially the same dimensions and being disposed in side-byf side relation with a relatively'thin strip of casing structure therebetween and with one pair of the opposed sides of one opening arranged in the same planes as the corresponding sides of the other openingy and with the other pair oi' op:- posed sides of said'one opening disposed parallel to the corresponding sides of the other opening;

anges formed integral with said casing and extending`v inwardly from each side edge oi'each of the openings to provide a pair bi rectangular. frames coextensive with their respective openings at the inside thereof; a louver frame assembly comprising a frame structure includingK outwardly extending flanges disposed in the' form or a pair of rectangles 'of the same shape and withP one pair of the opposed sides of one of the openings arranged in the same planes as the Y corresponding sides of the other opening and with the remaining sides of the openings arranged y in parallel relation to one another; flanges extending outwardly freni one side oi the l body member at each side edge of each Yof the openingsto provide a pair of rectangular subframes coextensive with their respective openings; a plurality of parallel equally spaced pivot lli rods extending across both openings and connected to the anges of the sub-frames; and louver plates Jpivotally mounted on the rods within each of the openings.

13. An air circulating device for usein room spaces, comprising a casing having an opening therein; av plurality of parallel louvers extending across the" opening and pivotally connected at `their ends to opposite defining edges of the opening so as to move about parallel axes; a flange member extending from each of the louvers inwardly from the casing at one side of the openl ing; link means connecting the ilange members for moving the louvers in unison; an operating pin connected to the ange of one of the louvers and arranged parallel to its axis of movement; an operating lever mounted for pivotal movement about an axis parallel to said pin and having a slotted end engaging said pin; and an @arcuate-shaped spring member disposed substantially concentric with the axis of movement of 'the slotted end of the lever and being in engagement with the latter; said spring member being Vanchored at its ends at opposite sides of the slotted end of the lever and having spaced-apart notch portions therein, in which the slotted end of the lever is adapted to nt and be resiliently j held thereby 'whfgi at predetermined positions.

" FRANCIS C. KILB.