US2183826A

US2183826A - Suction cleaner

Info

Publication number: US2183826A
Application number: US96222A
Authority: US
Inventors: Charles H Taylor
Original assignee: Hoover Co
Current assignee: Hoover Co
Priority date: 1936-08-15
Filing date: 1936-08-15
Publication date: 1939-12-19
Anticipated expiration: 1956-12-19
Also published as: GB494265A; FR821754A; USRE22594E; DE678607C

Description

Dec. 19, 1939. c. H. TAYLOR SUCTION CLEANER 2 Sheets-Sheet Filed Aug. l5, 1956 ATTORNEY Dec. 19, 1939. c. H. TAYLOR sUcTIN CLEANER Filed Aug. l5, 1936 2 Sheets-Sheet 2 3.52. I 21./ xNvENToR Charles b. [ZJ/[0r ifa ATTORNEY Patented' Dec. 19, 1939 2,133,826 sUo'rIoN CLEANER Charles H. Taylor, North Canton, Ohio, assignor to The Hoover Company, North Canton, Ohio,

a corporation of Ohio Application August 15,

12 Claims.

This invention relates to improvements in suc'- tion cleaners and more particularly to an improved nozzle height adjusting mechanism for regulating the height of the nozzle of a suction cleaner above the surface to be cleaned. For the purpose of distinguishing the improved mechanism from the type previously in use, it may be defined as automatic in its operation, thus drawing a sharp line of distinction between the raising and lowering the nozzle manually by means of a hand operated adjusting device and a device which automatically sets or regulates the height of the nozzle to the particular floor covering to be cleaned.

As well known in the art of suction cleaning,

1 the effectiveness of the operation is dependent in a large measure upon the proper initial setting of the nozzle above the surface to be' cleaned and the height adjustment for one type of carpet or rug may not be correct for another type. Actually, then, it is only possible to maintain a high degree of cleaning effectiveness by resetting the nozzle adjustment for each kind or grade of floor Y covering to be cleaned. But heretofore such precise adjustment has been quite impossible and chiefly because the average operator has neither the knowledge or the patience needed to keep the nozzleiheight adjustment properly set.

Without entering into a detailed discussion of the effect of nozzle height adjustment upon emcient cleaner operation, it. can be stated that for the average or ordinary grades of carpets and rugs, a constant setting of the suction nozzle will produce fairly satisfactory results. Butv with the existing trendtoward a wide variation in kinds and textures of iloor coverings, it is practically impossible tomaintain effective cleaning performance by manual nozzle height adjusting meansthis being particularly true of carpets and rugs which differ considerably in thickness and depth of the pile and hence, the amount that r the wheels will sink into the nap.

This statement explains suiciently the object of the invention and also the desirability of a 1936, Serial No. 96,222

linoleum covered floor to an extremely soft, thickpiled Chinese rug, it is possible to effectively clean by suction al1-floor surfaces or coverings between these two extremes.

With this introduction, a suction cleaner of the more or less standard type and design and equipped with the improved nozzle adjusting mechanism will now bel described in connection with the accompanying drawings wherein:

Figure 1 is a view in side elevation of a suction cleaner in its normal operating position and with a portion ofthe side wall broken `away to show the supporting carriage or chassis and the nozzle adjusting mechanism associated therewith;

Figure 2 is a bottom plan yview of the cleaner:

Figure 3 is also a View in side elevation of the cleaner, but of the opposite sidev from that of Figure 1;

Figure 4 is a detailed view in vertical section taken on line of Figure 1;

Figure 5 is also a detailed view -in section ,taken on line 5--5 of Figure 1, and i Figure 6 isa view in side elevation corresponding to Figure 1, but with the nozzle height adjusting mechanism shown with the parts thereof transposed by the depression of the foot lever.

Referring to the cleaner in its general aspects, the same comprises a main casing l, having a nozzle portion 2, extending transversely of its forward end and having the form of an'elongated chamber with a downwardly facing opening. The

casing extends rearwardly from the nozzle portion, gradually converging to a rearwardly openingflanged outlet connection 3 to which C attached a dirt receptacle in the form of a fabric bag 4. Centrally of the casing l is a circular fan chamber 5,v visible from the underside thereof, and enclosing a fan 6, having direct driving connection with a motor (not shown) enclosed within a domelike cover or hood 1 surmounting the casing I. The inlet to the fan chamber has the form of a circular opening or eye 5a located centrally of the bottom wall of the fan chamber and concentric with the vertical axis of the fan and its driving motor. Surrounding the rear half of the fan eye 5a and extending forwardly towards the nozzle portion 2, with a slight outward are is a depending 'wall 8 curving abruptly through a right angle as it approaches the nozzle and forming the rear Wall thereof at its outer ends. This depending wall forms the sides of a passage extending forwardly nd communicating with the interior of the nozzle 2, saidpassage being closed at' its bottom by a plate 9, having an upwardly facing marginal groove bearing against the bottom edge of the wall 8 and suitably lined with a resilient material to form an air tight seal. 'Ihis bottom plate 9 is shaped to conform with the outline of the wall 8, and preferably comprises, as an integral part thereof, the bottom section of the nozzle portion 2, consisting of a pair of parallel lips 9a, 9o, connected at their ends by means of a pair of

end lips

9b, 9b. These lips form the relatively wide suction mouth leading to the nozzle chamber immediately above and in which is located a rotating agitator I0, consisting of a cylindric shell having brush elements Illa, Illa, arranged lengthwise thereof and helically arranged beater elements Illb, IIlb. The bottom plate 9 is removable to uncover the nozzle chamber and the passage leading rearwardly therefrom, being detachably held in place by av suitable latch member II at the extreme rear end of the bottom plate. Also enclosed within the passage from the nozzle chamber to the fan chamber is a drive belt I2 engaging a pulley I3 carried at the lower end of the.fan shaft and extending forwardly therefrom engages a pulley groove IIIc midway between the ends of the agitator I Il and immediately above a guard member I4, extending transversely of the suction mouth, as clearly shown in Figure 2.

Again referring to the main casing I, with its centrally disposed circular fan chamber 5, it will be noted that alongthe edges of the casing and extending rearwardly from the ends of the nozzle 2 are depending curvilinear walls Ia, Ia, and between these depending marginal walls Ia, Ia, and the outer side walls of the fan chamber 5, are cavities or hollow spaces I5 which have a depth substantially equal to the height of the casing I itself. It is within these cavities enclosed by the marginal side walls Ia, la, of the cated beneath the rear end of the casing.

casing, that is located the wheeled support for the casing as Well as the nozzle adjusting mechanism associated therewith.

Referring first to the supporting means for the cleaner, the same comprises a common arrangement of carrier wheels I6, I6 journaled or supported just inwardly from the sides of the casing and immediately to the rear of the nozzle portion thereof and a pair of wheels I1, I1 having more the character of a two-wheeled caster lo- But in the present arrangement the front and rear wheels are not mounted separately upon the cleaner casing as is the more common construction but are carried on a separate frame member-to form therewith a carriage or chassis which supports the entire cleaner. This carriage or chassis has a two point connection with the casing, one being a pivotal connection just forwardly of the rear caster assembly and which permits the entire cleaner body to tilt about a horizontal axis and the other, an adjustable connection between the forward ends of the chassis and the casing through an intermediate foot operated pawl and ratchet mechanism, which functions to bring about` the desired tilting of the cleaner body on the wheeled chassis and thus maintain the desired elevation of the nozzle above the carpet surface.

Referring particularly to the frame which forms the chassis or carriage, the same is a U- shaped casting I8, pivotally connected centrally of its base portion at the lower end of a bracket I9 depending from the underside of the fan chamber 5. The frame member has an integral bearing bracket 20 consisting in part of a pair of spaced transverse webs which straddle the supporting bracket I 9. At the outer end of the bearing bracket 20 is mounted a transverse axle 2| on which the rear Wheels or casters I1, I1 are journaled. A pivot pin 22 passes horizontally and transversely through the supporting and bearing brackets I9 and 20, the underside o f the frame member I8, being recessed as shown in Figure 2, to Aaccommodate the enlarged ends of the bolt which serves as the pivot pin 22.

Now, from the point of pivotal connection of the frame member I8 with the underside of the casing I, the lateral extremities thereof curve forwardly within the cavities I5'between the wall of the fan chamber and the outer marginal walls Ia, Ia, of casing I, terminating just rearwardly of the nozzle portion 2, in the form of

fork members

23, 23, in which the front wheels I6, I6 are supported, .the same being journalled on

bearing shafts

24, 24, at the ends of said fork members.

Pivotally connected to the chassis I8 just rearwardly of and above the front

wheel supporting members

23, 23 is an inverted U-shaped bail member 25 which forms the lower extremity of the handle of the cleaner and, straddling the dome-like cover 1, projects through

longitudinal slots

26, 26 in the top wall of the casing I with its ends pivotally connected to bearing

bosses

21, 21, integral with the innermost portion of the chassis frame I8 and projecting laterally and inwardly therefrom (Figure 4). Thus the cleaner handle is carried by the wheeled chassis and quite independently of the casing I.

Associated with the handle bail 25 and co-acting with the chassis frame I8 on the side opposite the nozzle adjusting mechanism (Figure 3) is a handle position control device which serves to restrain the handle from free swinging movement and to define its extreme position as well as its intermediate or working range. 'I'his device is already in common use, except that in its present application the action is between a cam sector carried by the handle bail and a spring pressed roller mounted on the chassis instead of on the cleaner casing. Thus, as clearlyshown in Figure 3, the cam sector 28 is fixed to the end portion of the handle vbail 25 on the side of the cleaner opposite the nozzle adjusting mechanism, said sector projecting below the bail end pivot and having along its arcuate lower edge three notches, the endmost notches 28a being semi-circular in shape and the intermediate notch 28h being somewhat elongated. Now bearing edgewise against the notched edge of the sector 28, is a cam roller 29 carried at the free end of a bell crank lever 30 pivotally mounted intermediate its ends at the lower extremity of a depending web 3| integral with the chassis frame I8, the portion or arm 30a beyond the pivot point projecting upwardly and forming an abutment for one end of a compression spring 32, suitably supported on the chassis frame I8. Manifestly, the spring acting through -the lever 30 holds the roller 29'against the edge `I only at the point of pivotal connection just forwardly of the rear caster mounting. But, the cleaner casing is not free to turn at this pivotal connection, (limited as the arc would necessarily be) because of a second point of connection between the chassis frame I8 and the forward end t of the cleaner casing, namely, through a depending bracket 33 amxed to the top wall of the casing I and having a fiat slightly curved arm 33a extending downwardly with a rearward curvature, as shown in Figure 2. This bracket 33 is mounted immediately above the right front carrier wheel I6 with its depending arm portion 33a extending downwardly immediately inside the forked wheel supporting member 23. There is however, no direct connection between the adjacent end of the chassis frame I8 and the bracket 33, but rather an indirect connection through a link or ratchet sector 34 journaled on an extension of the same bearing shaft 24 that supports the carrier wheel I6.

As clearly shown in Figure 1, the ratchet sector 34 has the form of an elongated triangular shaped plate pivoted at its apex and extending rearwardly therefrom with its -bottom edge horizontal and its arcuate toothed edge facingrearwardly and adapted to be engaged by a pawl member presently to be described. This sector also has pin and slot connection intermediate its pivotal mounting on the bearing shaft 24 and its toothed edge with the bracket arm 33a, the latter carrying at its lower end, a laterally projecting pin 33h, engaging a relatively short slot 34a formed in the ratchet sector 34 and extending somewhat obliquely to the radial center line thereof. Thus it is apparent that the ratchet sector 34 provides a link between the chassis I8 and the casing I and that by rocking said sector vertically through a predetermined arc, a somewhat reduced rocking or tilting of the casing on its chassis will follow.

Now, journaled upon the same bearing shaft 24 which carries the wheel I6 and the ratchet sector 34 is an operating lever 35. This lever 35 extends rearwardly just inside the ratchet sector 34 and in a substantially horizontal direction, its rear end terminating practically in line with the pivotal axis of the chassis frame I8 and is there provided with a foot pedal 35a projecting laterally from beneath the lower edge of the marginal wall la, of the casing I. The foot operated lever 35 is normally held against downward movement by a relatively stii coil spring 36 attached at one end to the lever just forwardly of its pedal extremity 35a and extending vertically upwardly, is anchored at its upper end to a lug 31 depending from the under side of the chassis frame I8 immediately above.

And finally, a pawl 38 is pivotally mounted on the operating lever 35 substantially intermediate its ends and in the plane of said ratchet sector 34. A laterally projecting pin 38a supports the pawl 38 which, extending in a general upward and forward direction, is provided at its end with several teeth 3 8b, complementing the teeth along the arcuate edge of the ratchet sector 34. A torsion spring 38, coiled around the pivot pin 38a with one end hooked around a lug 35h at the lower edge of the operating lever 35 and the other end around the back edge of the pawl 38 as clearly shown in Figure 1, acts to yeldingly hold the pawl in engagement with the ratchet sector 34.

From the description of the pawl and ratchet mechanism to this point, it might be concluded that upon depressing the lever 35, the pawl would click over the ratchet teeth and upon releasing the same, the forward end of the casing would be raised a given distance; in other words, that it is butthe application of a typical pawl and ratchet adjustment. But this is not the case since such an arrangement would be only partially operative because the nozzle could not be lowered,;once it had been elevated to its extreme height, since there` would be no way of releasing the pawl to allow the nozzle to be lowered. It is to be understood therefore, that the present adjusting mechanism is not to be confused with a foot operated ratchet device for elevating thenozzle but is, on the contrary, an adjusting mechanism which functions with but a I single depression of the foot lever for setting the 'nozzle to the proper height for a particular surjface.

In other Words, the depressing of the operating lever causes the nozzle to be lowered into contact with the carpetl surface and upon releasing the lever the nozzle is elevated a predetermined xed amount 'or distance regardless of the previous setting. But in order to bring this action about, it is necessary to control the movement of the pawl 38 with relation to the ratchet sector 34.

Thus, referring to Figure 6, there will be seen immediately above the pawl 38, an arm 40 depending from the under side of the chassis frame I8 and along the inner side of the pawl, said arm carrying a laterally projecting pin 4I engaging a somewhat irregularly shaped slot 42 located in the central portion of the pawl 38. This pin and slot connection serves to impart a cam action to the pawl, throwing it into and out of engagement with the ratchet sector 34. More particularly the cam action controls the pawl yso that it disengages the ratchet sector at the beginning of the downward stroke of .the lever 35 and holds it in that position (as in Figure 6) until the lever is released, whereupon the pawl is qu'ckly thrown into engagement with the ratchet sector. That this cam action takes place is somewhat evident from the shape of the slot 42 in the pawl, being relatively wide at its lower end and converging toward its upper end thereby producing the oblique cam surface necessary to impart a quick lateral throw to the pawl as it shifts upwardly and downwardly with the operating lever 35.

Having thus set forth a structure embodying the improved nozzle adjusting mechanism, its operation will be understood from' the following discussion:

Let it be assumed that the cleaner has been wheeled onto a carpet preparatory to operating it thereon and that so far as the nozzle height adjustment is concerned', it may or may not be properly set for that particular carpet, although the nozzle is elevated above the carpet surface as shown in Figure 1. Now, to obtain the correct setting the operator merely depresses the lever 35 to its fullest extent and upon releasing it the ,nozzle of the cleaner is automatically adjusted to the proper height regardless of previous setting.

The automatic action will nowbe described in detail: When the foot operated lever 35 is de' pressed from the substantiallly horizontal position shown in Figure 1 to the postion shown in Figure 6 wherein the outer end practically contacts the carpet or floor surface, the first step isv the disengaging of the pawl 38 from the ratchet sector 34, by the cam action of the stationary pin 4I in the slot 42 of the pawl 38. Now, immediately upon the release of the ratchet sector 34 by the pawl. the entire forward end of the cleaner casing I is free to tilt downwardly until the suction mouth of the nozzle rests flush upon the carpet surface, for obviously, having released the pawl sector 34 the casing can rotate freely about its pivotal connection with the chassis I8 and, the greater mass of the cleaner being forwardly of the pivotal axis, the nozzle simply drops into contact with the carpet surface.

But an important point to be noted here is, that the bottom surface of the nozzle being made up of wide lips surrounding the suction mouth, affords a relatively large contact surface and of such area that there is no appreciable penetration or sinking of the nozzle into the nap or pile of the carpet. This is important because it is the plane of contact of the nozzle with the carpet that establishes the base from which the nozzle adjustment is made and this base will vary with the grade and type of carpet uponI which the adjustment is made. For example, if the cleaner is resting on a bare floor or a hard surface covering such as linoleum, the depressie-n of the foot lever 35 lowers the nozzle into contact with the surface and this surface coincides with the plane of contact of the wheels, because there is no surface penetration by either nozzle or wheels. But now assume that the cleaner is placed upon a rug or carpet having a definite nap. Manifestly, under the weight of the cleaner the wheels will sink to a certain depth into the nap and this will determine an apparent plane of contact lying somewhere between the tips of the carpet fibers and the bare floor, depending somewhat on the stiffness of the nap and the resiliency of the carpet backing. In otherwords, the plane of contact represented by thelwheel treads may vary considerably in a vertical direction from the actual carpet surface, which for the purpose of this discussion may be assumed to be the plane determined by the end of the upstanding carpet fibers, commonly called the carpet pile. But when the nozzle is lowered into contact with the surface of a carpet or rugits extended area does not cause any appreciable penetration of the pile, whereas the wheels may sink the full vdepth of the pile. Thus it is that the plane established by the nozzle resting upon the carpet pile is not only above that established by the wheels, but that, regardless of the character of the carpet, the base from which the adjustment takes place is always the plane of contact of the nozzle upon the upstanding carpet fibers and is xed regardless of the depth of wheel penetration.

Now, the vertical distance separating these planes is manifested g1 a slightlygreater or less relative displacement of th`e chassis I8 and the cleaner casing I in the act of depressing the foot pedal 35, and this displacement is in turn reected in a slightly greater or less variation in the angular displacement of the ratchet sector` 34 after it has been released by the pawl 38, as shown in Figure 6. This means, of course, that immediately uponA the disengagement of the ratchet sector by the pawl, it will swing downwardly through a small angle represented by one or more of the ratchet teethas the downward movement of the nozzle portion of the casing is transmitted thereto through the bracket 33. But with the base established by contact of the nozzle with the carpet, it is only necessary to release the operating lever 35, whereupon the spring 36 acts 'to retract the lever into normal horizontal position as in Figure l, the upward movement of the lever first throwing the pawl 38 into engagement with the ratchet sector 34, and thence swinging it upwardly in a counter-clockwise direction through a small arc, this movement of theratchet sector 34 being transmitted to the casing through the bracket arm 33 with a slight degree of lost motion due to the pin and slot convFor example, if g3g of an inch is predetermined as the proper nozzle height setting for a particular cleaner, the adjusting mechanism is designed to raise the nozzle this distance above the surface of the carpet pile regardless of the type or character of the carpet.

Thus, to summarize the important features of the so-called automatic nozzle adjustment, the first to be noted is that while the floor level determined by the plane of wheel contact is variable with different types and grades of carpets and rugs, the plane from which the adjustment is made, is always established by the contact of the nozzle with the true carpet surface and that this plane coincides with the pile surface regardless of the kind and texture of the carpet. And secondly, having established this plane from which thek adjustment is to be made, the distance to which the nozzle is elevated above said plane is constant for that particular cleaner, so that the ultimate result is that regardless of the type of floor covering to be cleaned, the proper nozzle height setting is quickly and accurately obtained merely by depressing the foot pedal and then releasing it, the interconnection between the pawl carried by the operating lever and the tooth ratchet sector acting automatically to set the nozzle at its proper and correct height for the most eective and economical cleaning.

Thus, it follows that the adjustment is automatic insofar as it relieves the operator of the necessity for exercising any judgment as to the proper nozzle height adjustment' for a particular carpet, this having previously been determined upon and incorporated in the design of the nozzle adjusting Y mechanism. Consequently,` the only responsibility the operator has is to depress and release the pedal and the cleaner functions auto matically to regulate or set its own height of nozzle adjustment for the particular carpet surface to be cleaned.

And finally, the incorporation of the nozzle adjusting mechanism in conjunction with a wheeled chassis supporting the cleaner casing so that the latter can be tilted to a slight angle about atransverse horizontal axis of pivotal connection, provides a Very compact and satisfactory means of combining the supporting and adjusting mechanism. On the other hand, it is not essential that the cleaner body be supported upon a separate oi independent carriage or chassis in order to obtain ,the automatic nozzle adjustment herein disclosed, providing either the forward or rear wheel mounting be pivotally connected to the casing of the cleaner. For example, in Figure 1, the rear caster mounting might readily be an 'integral -part of the casing I rather than of the chassis frame I8, thus devoting the U-shaped frame member I 8 to the mounting of the front wheels I6 and through which the elevating mechanism would still function quite as well to obtain the automatic adjustment of the nozzle.

Having thus set forth a preferred embodiment of my invention, I claim:

1. In a suction cleaner having a casing including a nozzle and a wheeled support having pivotal connection with said casing, means for ad- Justlng the height of said nozzle above the surface to be cleaned comprising an adjustable link connecting said support with said casing independently of vsaid pivotal connection and having `a toothed sector, an operator actuated lever pivpawl and sector to effect the raising of said nozzle a predetermined distance above said surface during the movement of said lever in the opposite direction.

`2. In a suction cleaner having a casing including a nozzle and a wheeled support having pivotal connection with said casing, means for adjusting the height of said nozzle above the surface of the carpet to be cleaned, comprising a ratchet sector pivotally carried by said support and having pin and slot connection with the underside of said casing at a point removed from its point of pivotal connection with said support, a foot-actuated operating lever mounted adjacent said ratchet sector, a spring-pressed pawl carried by said operating lever and normally engaging said ratchet sector to maintain said nozzle at a given height, means for shifting said pawl out of engagement withsaid ratchet sector in the movement of said operating lever in one direction thereby allowing said nozzle to drop into contact with the carpet surface, and to effect its reengagement with said ratchet sector at the commencement of the return movement of said operating lever to elevate said nozzle to a predetermined distance above the carpet surface, and tension means acting to facilitate the return movement of said operating lever.

3. In a suction cleaner having a casing including anozzle portion and a wheeled support pivotally connected to the underside of said casing and having wheels journaled thereon, means for adjusting said casing relative to said wheeled support to vary the height of said nozzle above the surface of the carpet to be cleaned, comprising an adjustable link connecting said casing with said wheeled support and provided with a toothed sector, a foot operated lever pivotally mounted on said wheeled support, a spring pressed pawl pivotally mounted on said lever and normally adapted to have toothed engagement with said sector, means actingto shift said pawl to release said sector during the depression of said lever tihereby eiecting the lowering of said nozzle into contact with the carpet surface and to allow the pawl to reengage said sector at the commence-` ment of the return movement of the lever to effect the elevation of said nozzle to a predetermined height above said carpet surface, and tension means acting on said lever to impart the return movement thereto.

4.- In a suction cleaner having a casing with'a nozzle at its front end and a wheeled carriage extending lengthwise beneath said casing and pivotally connected therewith adjacent the rear end thereof, an adjustable -ratchet sector connecting said casing with said wheeled carriage adjacent the front end of said casing, an operating lever pivotally mounted on said carriage adjacent said ratchet sector, a pawl pivotally mounted on said operating lever, tension means acting on said pawl to hold the same normally in toothed engagement with said sector, Atension means acting on said operating lever to hold the same in its normal position wherein the nozzle portion of said casing is supported at a prede. termined height above the floor level, and a cam acting on said pawl member during the movement of said operating lever in one direction to release said sector whereby said nozzle is permitted to drop into contact with the surface of the floor cdvering and, upon the subsequent release of said operating lever and its return to its normal position under the tension of said spring to reengage said pawl with said sector and thereby actuate said link to raise said nozzle a predetermined fixed distance above the surface of said floor covering. v

5. In a suction cleaner having a body including a nozzle and a wheeled support having pivotal connection with the underside of said casing, a link connecting said support with said casing whereby the vertical rocking movement of said holding said link against movement including a spring-pressed link-engaging member, a springactuated lever operatively connected with said link-engaging member, a fixed cam member acting to shift said link-engaging member in a direction to disengage said link in the movement of said lever against the tension of its spring thereby to cause said nozzle to drop downwardly into contact with the carpet surface and to effect the re-engagement of said link by said link-engaging member at the moment said lever is released and commences its return stroke under the tension of its spring, thereby raising said nozzle to.a predetermined height above the carpet surface.'

6. In a suction cleaner having a body including a nozzle and a wheeled support pivotally connected to said body, a link also pivotally connecting said body with said support and having a ratchet sector, a spring-pressed pawl normally engaging said ratchet sector, a lever carrying said pawl and adapted to be shifted in opposite directions, said pawl having pin and slot connection with said support whereby it is disengaged from said ratchet sector during the movement of said lever in one direction and into engagement with said ratchet sector at the commencement of the movement of said lever in the opposite direction, whereby said nozzle is lowered into contact with the surface of the floor covering to be cleaned and thence raised'to a predetermined height above said surface.

7. In a suction cleaner having a body including a nozzle and a wheeled support pivotally connected to said body, a link connecting said body with said support and having a toothed ratchet sector, a spring-pressed pawl normally engaging said ratchetsector to maintain said body in fixed relation to said support, and mechanism` for operating said pawl successively to release said ratchet sector thereby to permit said body to drop under its own weight until said nozzle contacts the floor and to reengage said ratchet sector and raise said nozzle to a predetermined height above the floor.

8. In a suction cleaner having a. body includof pivotal connection, a pawl normally engaging 'I said ratchet member to maintain said body in fixed relation with said support, an operating lever mounted on said support and having operative connection with said pawl, and means for shifting said pawl out of engagement with said ratchet member in the movement of said lever in one direction thereby permitting said body to drop downwardly with said nozzle resting on the surface of the oor covering to be cleaned and thence into engagement with said ratchet mem-4 ber at the commencement ofthe return stroke of said lever to raise said body to a height predetermined by the movement of said ratchet member during the return stroke of said lever.

9. In a suction cleaner having a casing in'- cluding a nozzle and a wheeled support having pivotal connection with said casing, means for adjusting the height of said nozzle above the surface to be cleaned, comprising a link connecting said wheeled support with the nozzle end of said casing and having a ratchet sector, a lever pivotally mounted on said wheeled support, a springpressed pawl carried by said lever and normally engaging said ratchet sector to hold said link against displacement, said pawl being cam controlled to disengage said pawl from said ratchet sector in the movement of said lever in one clirection to allow said nozzle to drop into contact with the surface to be cleaned and to re-engage said sector at the commencement of the return stroke of said lever and elevate said nozzle to a predetermined height above said surface.

10. In a suction cleaner having a casing including a nozzle and a wheeled support having pivotal connection with said casing, means for adjusting the height of said nozzle relative to the surface to be cleaned comprising a link connecting said wheeled support with said casing and provided with a ratchet sector, an operating lever pivotally mounted on said support, a pawl carried by said lever and n ormally engaging said ratchet sector to hold said nozzle in a given position of adjustment, a cam mounted on said support and acting to shift said pawl to release said ratchet sector in the movement of said lever in one direction and permit said nozzle to drop into contact with the floor surface and to shift said pawl into engagement with said sector at the commencement of the return stroke of said lever and elevate said nozzle to its predetermined height above the surface to be cleaned.

11. In a suction cleaner having a casing including a nozzle and supported upon a carriage having .pivotal vconnection with the underside of said casing, means for adjusting the height of said nozzle above the surface to be cleaned, comprising a link pivotally connecting said carriage with said casing adjacent the nozzle end thereof, an operating lever pivotally mounted on said carriage, a spring-pressed pawl carried by said operating lever and normally engaging said ratchet sector to hold said casing in a fixed relation to i said carriage, a fixed cam member on said car riage and engaging a slot in said pawl to shift the same out of engagement with said ratchet sector upon the movement of said operating lever in one direction thereby permitting said nozzle to drop into contact with the carpet surface and to shift said pawl into reengagement with said ratchet sector at the commencement of the movement of said operating lever in the opposite direction thereby to raise said nozzle to a predetermined height above the surface to be cleaned.

12. In a suction cleaner having a casing and provided with a nozzle at its forward end and a wheeled carriage pivotally connected to its underside adjacent its rear end, a link connecting said carriage with said body adjacent said nozzle and adapted to swing in a vertical plane to vary the height of the nozzle above the ysurface to be cleaned, a foot-actuated lever pivotally mounted on said carriage, a spring acting on said lever to yieldingly oppose -its depression, a springpressed pawl mounted on said lever and normally engaging a ratchet sector on said link to hold said casing in a xed position "of nozzle height adjustment, a cam acting on said pawl to shift the same out of engagement with said ratchet sector upon the depression of said lever thereby permitting said nozzle to drop into contact with the carpet surface and to re-engage said pawl with said ratchet sector at the commencement of the return movement of said lever and thereby raise said nozzle to a predetermined height above said surface.

CHARLES H. TAYLOR.