US2244132A - Suction cleaner - Google Patents

Description

June 3, 1941'- c. H. 'TAYLOR SUC TION CLEANER Filed May 9, 1938 3 Sheets-Sheet l INVENTOR Charles H T a ylor ATTORNEY 4 SUCTION CLEANER Filed y 1938 s Sheets-Sheet 2' 8 INVENTOR Charles H Taylor ATTORNEY June 3, 1941..

3 Sheets-Sheet 5 3. H. TAYLOR SUCTION CLEANER Filed May 9, 1938 /IIIIIIIIIIIIIl/IIIIII III/Illa), VIII/I/l/I/II/l INVENTOR Charles]?! Tayiar A A N. 'llw M a v.

unnn'nwAnAnJmlAill ATTORNEY Patented June 3, 1941 SUCTION CLEANER Charles H. Taylor, Springfield, Mass, assignor to The Hoover Company,

corporation of Ohio North Canton, Ohio, at

Application May 9, 1938, Serial No. 206,739 3 Claims. in. 15-16) This invention relates to improvements in suction cleaners and more particularly to means whereby the nozzle of a suction cleaner is automaticallymaintained at the correct'height above the surface of the floor covering to be cleaned regardless of its quality, texture or other characteristics. I

Heretofore, it has been the standard practice to equip suction cleaners with some form of manually operated mechanism or device for adjusting the height of the nozzle for different grades and texture of carpet, it being well known that a predetermined uniform spacing of the nozzle above the carpet surface is essential to efficient operation and effective cleaning and further, that the nozzle should be raised or lowered to compensate for varying depths to which the wheels sink into carpets having different pile thickness. The chief objection to these manually operated adjusting devices is the fact that it is usually difficult for the operator to make the correct adjustment, not being familiar with the operating conditions. Moreover, operators frequently neglect to make any adjustment at all and as a consequence, the compensation for variations in carpet conditions is at best, uncertain and haphazard.

Therefore, the principal object of the invention is to incorporate a nozzle adjusting device into a suction cleaner that will automatically adjust itself to the particular kind or texture of carpet .to be cleaned and thus eliminate the necessity of relying upon the operator to perform any act other than placing the cleaner upon the floor covering and operating it in the usual manner.

And a further-object of the present invention is to provide a type of automatic nozzle height adjusting or regulating mechanism consisting of dual wheels vertically adjustable against spring tension to support the load, and so interconnected that the displacement ofone wheel in contact with the carpet surface adjusts the other wheel, which in turn determines the correct height of the nozzle.

With the foregoing introductory matter, the invention will now be 'more fully disclosed in connection with the accompanying drawings in which: v

Figure 1 is a geenral view in side elevation of a suction cleaner embodying the features of the invention and shown under operating conditions on a carpet ofmedium thickness.

Figure 2 is a fragmentary bottomplan view of the cleaner showing one set of adjustable wheels.

Figure 3is a fragmentary view of the adjusting mechanism set for operating on a relatively thick carpet and shown in side elevation as taken on line 33 of Figure 2.

Figure 4 is an enlarged detail view in vertical cross section taken on line 44 of Figure 1.

Figure 5 is a perspective view of the adjusting mechanism assembly. i Figure 6 is a perspective view of the bell crank lever forming a part of the adjusting mechanism.

Figure 7 is a view in side elevation of a modified nozzle height adjusting mechanism; and

neuvered cleaner adapted for household use and consisting generally of a casing I mounted on wheels and provided with a nozzle portion 2 extending transversely at itsforward end. The casing I includes a fan chamber 3 in which is mounted a suction fan driven by a motor enclosed within a dome-like hood 4 on the casing. The nozzle portion of the casing consists-primarily of a downwardly opening nozzle chamber communicating with the fan chamber through a suitable inlet passage, said fan chamber communicating with a dirt bag 5 having detachable connection with anlexhaust outlet connection at the rear end of the casing I. A handle completes the cleaner assembly, the lower end portion in the form of a U-shaped bail 6 being pivotally connected to brackets I, on opposite-sides of the casing I. 1 Otherwise, the cleaner embodies the usual features of design which need not be described in detail.

The cleaner casing is supported upon wheels positioned near the front and rear ends thereof, the rear wheels 8, 8 being of standard size and dimensions and are journalled upon a suitable bracket 9 fixed to the cleaner casing. These wheels function in the usual manner to support the rear portion of the cleaner and will not be further considered.

The front wheels however, consist of two sets or pairs arranged side by side and substantially in axial alignment with each other, and are capable of adjusting themselvesautomatically under operating loads and in a degree determined by the characteristics of the carpet cleaner is being operated.

Referring in greater detail to the front wheel arrangement, the corresponding wheels of each pair are-located immediately to the rear of the outer end portions of the nozzle chamber and on which thecasing and may be further distinguished by the fact that they are substantially wider than. the secondary or auxiliary wheels II, II which are positioned just inwardly from and in close proximity to the supporting wheels. For the purpose of the present discussion the primary supporting wheels I may be assumed to be about three times the width of the narrow auxiliary wheels II, which have a width of say one-quarter A) of an inch.

The supporting wheels HI, ID are journalied at the forward ends of pivoted supporting brackets I2, 'I2 preferably assembled from sheet metal parts and pivotally supported, with corresponding brackets I3, I3 for the auxiliary wheels II, II, upon frames I4, I4 fixed to the underside of the cleaner casing. Each of the wheel supporting frames I l (Figure 5) isstamped from sheet metal with ears Ida, Isa at each end which bear against depending bosses I5, I5 integral with the underside of the cleaner casing and to which the frame is fixed by means of screws to assume an inclined position at an angle of about 45. The main portion of each frame I I consists of a vertical central web It roughly triangular in shape with marginal segments 'on opposite sides thereof for supporting the several parts of the wheel assembyl. Thus, at the upper end of the frame is a downwardly projecting integral arm I! supporting between its lower end and that of the web I6, a bearing pin I8 on'which bushing or collar I9 is mounted. This bushing I9, preferably flanged at either end, forms the bearing for the supporting wheel bracket I2, having the general shape of a bell crank lever (Figure 6) and consisting of a pair of L- shaped plates 20, 20, spaced apart with their horizontal arms a, 20a extending forwardly and supporting the ends of the journal pin I0a for the front wheel III. The other and vertical arms 20b, 20b of the plates 20, 20 are bent at right angles just above the bushing I9 and laterally inward and again bent upwardly at right angles and into contact with each other and finally joined together into a single upright lever arm offset some distance inwardly from the plane of the wheel l0 supported by the main portion of the bracket with the extremity of one of the upright arms fashioned into a ta pered or wedge-shaped cam 2| extending rearwardly with a slight inclination in an upwardly direction, the under edge of this cam being the active cam surface, and inclined to the vertical at an angle of approximately 45.

To complete the pivotal mounting of each supportin wheel bracket I2 on the supporting frame It a torsion spring 22 consisting of approximately three turns is coiled about the bushing I9, one end of the torsion spring being hooked about the rear edge of the wheel supporting bracket I2 immediately above the bearingl9 (Figure 4) and the other extremity of the springbeing caught over a finger 23 formed integral with the outlying 1 arm II of the frame I4 (Figure 5), the torsion spring thus acting to exert continuous pressure on the wheel supporting bracket I2 in a direction to yieldingly resist the load placed upon the supporting wheels Ill, II] when the cleaner is in operation. In other words, each torsion spring 22,

' tends to rotate its wheel supportingbr acket I2 in a clockwise direction as viewed in Figurel. However, it is to be noted at this point that the tension exerted by the torsion springs 22 is calculated to be considerably less than that necessary to overcome the operating load on the front wheels, although ample to support the-front portion of the cleaner under static load conditions, that is, when the cleaner is not operating under suction load, as will presently be explained in greater detail.

In the meantime, it may be observed that the rotative movement of the wheel carrying brackets I2, I2 on their bearings I9, I9 is transmitted from each associated auxiliary wheel carrying brackets I3 through the medium of a Z-shaped cam lever 24 pivotally mounted on a bearing pin 25 carried on the frame It directly to the rear of the pivotal axis of the wheel supporting bracket I2 and projecting inwardly beyond the central web I6 of the frame.

Leaving the Z-shaped cam lever 24 for the moment, the supporting bracket I3 for each of the auxiliary wheels II i located just inwardly from the primary wheel supporting bracket I2 and consists of an elongated U-shaped lever formed of sheet metal and having bearing at its rear end upon a transverse pivot pin 26 supported at the rear end of the frame I4; This wheel supporting lever I3 extends in a horizontal direction and throughout its forward end portion it is bifurcated to receive the narrow auxiliary or pilot wheel II. As clearly shown in Figures 2 and 4, each lever I3 has an upwardly opening U-shaped portion 21 with a section of its outermost side Wall cut away as at 21a to allow the pivot pin 25 to project into the'open U-shaped recess and to bring the Z-shaped cam lever 24, previously identified, into position immediately above the lever.

Now, the cam lever 24 carries at its lower end and just forwardly of its pivotal support on the pin 25, a roller 28 which bears upon a narrow metal plate or strip 29 extending along the bottom of the U-shaped recess intermediate the ends of each lever I3, said strip being suitably anchored as by welding at its rearmost end. Im-

mediately beneath the forward and free end of the strip 29 is an adjusting screw 30 threaded through the bottom web of the lever I3 and bearing at its upper end against the underside of the plate 30 which, being somewhat resilient, is adapted to be raised or lowered thereby to impart a limited adjustable rotative movement to the Z-shapedcam lever 24 by contact with the roller 28. The adjusting screw 30 is provided with a lock nut 3i to hold the same in any position of adjustment. The purpose of this adjusting screw will' be brought out in connection with the discussion of the operation of the nozzle adjusting mechanism.

As thus .far described, each Z-shaped cam lever 24 pivots about its-bearing pin.25, the

mation of the cam lever 24, a short arm 24a projects rearwardly from its upper end with its extremity bent at right angles and folded back upon itself to form an abutment for one end of a compression spring 33. The opposite end of downwardly by said spring is supported at the end of a tension adjusting screw 34 supported by an ear 35 formed integral with the supporting bracket l4 and extending transversely from the rear edge of the central web |6 thereof (Figure A lock nut 36 is applied to the outer portion of the adjusting screw 34 which also has its end slotted transversely so that a screw driver may be applied for rotating to either increase or decrease the pressure exerted by the coil spring 33 on the Z-shaped cam lever 24.

'I'his completes the description of each adjustable front wheel assembly and, bearing in mind that the same is duplicated on each side of the cleanenthe adjusting action may be suinmarized as follows: The outermost or wide supporting wheels l0, l0 are adjusted upwardly and the rocking movementof their supporting brackets l2, l2 limited however to the movement thereto through the contact of Y the cam rollers 32, 32 with the cams 2|, 2| which in turn depends upon the degree of rocking or oscillating movement imparted to the Z-shaped cam levers 24, 24 by the movement of the sup porting brackets l3, or narrow auxiliary wheels H, It follows therefore that if the auxiliary wheels are permitted to be depressed below their normalhorizontal position, this movement allows the cam levers 24, 24 to rock forwardly under the tension of the springs 33, 33 and transmit a rocking movement to the main wheel supporting brackets l2, l2, in the same direction, that is, downwardly in a clockwise direction, with the result that the primary load supporting wheels l0, ID are depressed and the forward end of the cleaner body is elevated to raise the nozzle accordingly.

And in this-connection, it is important to note that the auxiliary wheels I II are journalled at the ends of lever arms considerably longer than the lever arms a of the brackets l2, I2 carrying the supporting wheels Ill, Ill, and hence, the force exerted by the springs acting through the former is greater than that acting through the latter with the result that the auxiliary wheels II are depressed with greater force and therefore assume a greater part of the load,

say, from 75 to 80% with the main supporting wheels l0, l0 carrying the remaining or 20% of the load. However, this applies only to the static load, so that upon starting the cleaner in operation, the suction load becomes effective and immediately there is a tendency for the wheels to sink or penetrate to a greater depth into the carpet 'nap. Now, since theauxiliary wheels II are capable of carrying the greater l3 carrying the innermost nalled at the end of alonger lever load before yielding to the added weight imposed upon them, it follows that they will sink into the carpet nap to the maximum depth permitted by the thickness and texture of the carpet pile andwhen that depth is reached, the auxiliary wheels will move toward the cleaner casing and the movement of the supporting levers |3, |3 will be transmitted to the brackets 2, l2

carrying the main supporting wheels I, I0,

through the cam levers 24, 24. And since the main supporting wheels l0, ID are intended pri marily to carry only the suction load and to ride upon the carpet nap with little penetration, due to their relatively wider tread surfaces, their vertical position determines the ultimate height of the nozzle above the carpet surface. In short, the wide wheels l0, I0

" are displaced vertically and move upwardly or downwardly with the auxiliary wheels II but in a reduced amount proportional to the relacomparatively '7 tive lengths of their respective-lever arms. Thus it will be seen that the carpet pile, the greater the penetration of the auxiliary wheels II and the correspondingly greater vertical adjustment of the supporting wheels l0, ID in a direction to raise or lower the nozzle and thus maintain its uniform height regardless of the particular characteristics of the carpet being cleaned.

However, before starting the cleaner in operation, the adjusting mechanism has to be properly set by manipulating either the bottom adjusting screw 30 or the compression spring adjusting stem 34, or both. This setting would ordinarily be made before the cleaner leaves the factory and based on a predetermined nozzle height of say, ft; of an inch as measured between the front lip of the nozzle mouth and the surface of the carpet nap. And this setting once made would ordinarily be permanent whereupon the 'cleaner should respond to variations in quality and texture of the ordinary-range of carpets to be cleaned.

Thus, the characteristic features of the adjusting mechanism herein disclosed is the utilization of pairs of adjustable wheels, one pair being relatively more responsiveor susceptible to variations in the quality and texture of the carpet than the other, and of the latter which in turn determines the height of the nozzle. Needless to say, the same principles may be incorporated in other and even simpler forms, one of which has been disclosed'in Figures 7 and 8.

In the modified disclosure of the adjusting mechanism, the wheels ,constitutingeach set are located at the forward end of the cleaner as before, butare positioned one behind the other rather than side by side. Moreover, foremost wheels 40, 40 are relatively wider and constitute the primary Wheels, while 4| are the auxiliary wheels. wheels 40 is journalled at the lower end of a short lever 42 pivotally mounted intermediate its ends at the lower .extremity of a vertical arm 43 formed integral with a. bracket 44 suitably fastened to the underside of the cleaner casing. Each of the auxiliary wheels 4| is similarly jouralso having pivotal connection with the arm 43 just above the pivot point of the le r 42 and extending downwardly and rearwandly therefrom. Bearing against the levers 42 and 45 adjacent their outer ends are compression springs 46 and 41 respectively with their other ends seating against abutments formed by the bracket 44.

The rearmost wheels 4|, 4| correspond to .the auxiliary wheels H of the previous disclosure and therefore, the compression springs 41, 41 are heavy enough to counterbalance the greater part of the static load, while the springs 43 are somewhat lighter and act primarily to resist the displacement of the front wheels under load. And finally, the levers 42 and 45 are interconnected by a simple cam arrangement consisting of a pin 48 projecting from the face of the longer lever 45 and bear g against a cam finger 42a at the upper end of the lever 42.

Thus, as the rear wheels 4|, 4| sink into the carpet nap under operating load, the depth of penetration is reflected inthe slightlswinging movement of their supporting levers 45, which is transmitted to the levers 42, a direction to depress the forward wheels and thus act in the same manner as the wheels l0,

Each of the primary the greater the depth of.

acting to adjust the position the rear wheels 4|,

shifting them in If) in the previous disclosure to raise orlower the nozzle and thus compensate for the varia- 7 tion in the thickness and texture ofthe carpet.

ing on said auxiliary wheel supporting brackets to oppose yieldingly to the displacement of said auxiliary wheels under the weight of-the cleaner 1 body, said primary wheel supporting bracket having a cam member bearing on said spring-pressed lever, whereby the increased depth of penetration of said auxiliary wheels under full operating load condition of said cleaner by virtue of their decreased width, effects a proportional displacement of said primary supporting wheel to adjust automatically the height of said nozzle to the particular carpet surface being cleaned.

arranged substantially in axial alignment-therewith, brackets pivotally mounted on said body and carrying said auxiliary-wheels, springs acting on said auxiliary wheel supporting brackets to counterbalance a predetermined portion of the weight of the cleaner body, a lever shiftable with the displacement of each of said auxiliary supporting brackets caused by the depression of said auxiliary wheels into the carpet surface under the operating load-of. said cleaner, and a cam member on each of said front wheel supporting brackets and contacting said lever to effect a corresponding vertical displacement of said primary supporting wheels/and adjust automatically theheight of the nozzle to the depth of penetration of said auxiliary wheels into the surface of the carpet to be cleaned.

2. A' suction cleaner comprising a body having a nozzle at its forward end and pairs of front and rear supporting wheels, 'the front wheels 3. A suction cleaner comprising a body having a nozzle at its forward end and pairs of front and rear supporting wheels, the front wheels consisting of pairs of associated primary and auxi1iary wheels having relatively wide and narrow tread surfaces respectively, frames mounted on said body, pairs of brackets pivotally mounted side by side on said frames and having horizontally extending arms carrying said wheels at their forward ends, spring-pressed levers carried by said frames and acting on said auxiliary wheel supporting brackets to oppose yieldingly to the displacement of said auxiliary wheels under the weight of the cleaner body, said primary wheel supporting brackets having cam members bearing on said spring-pressed levers, whereby the, increased depth of penetration of said auxiliary wheels under full operating load condition of said cleaner by virtue of their decreased consisting of pairs of associated primary and auxiliary wheels having relatively wide and narrow tread surfaces respectively, and arranged side by side in substantially axial alignment, brackets pivotally mounted on said body and having horizontally extending arms carrying said wheels at their ends, spring-pressed levers actwidth and'the increased length of the lever arms of their supporting brackets, effects a proportional displacement of said primary supporting wheel to adjust automatically the height of said nozzle to the particular carpet surface being cleaned.

CHARLES H. TAYLOR.

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