US2497886A

US2497886A - Carpet sweeper

Info

Publication number: US2497886A
Application number: US420443A
Authority: US
Inventors: Heftler Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-11-26
Filing date: 1941-11-26
Publication date: 1950-02-21
Anticipated expiration: 1967-02-21

Description

Feb 21, 1950 Filed NOV. 26, 1941 3 Sheets-Sheet l 9 w a B .5 4 7, IO w 9 4 3 6 W +3 a (k w s I 4 I G ./L no 2 w 4 e 4| w J 4/ 3/ FIG 2 (BOTTOM VIEW) FIG. 6'

za /gem FIG. 5

P. HEFTLER Feb. 21, 1950 CARPET SWEEPER 3 Sheets-Sheet 2 Filed Nov. 26, 1941 II IPIIIIIIIIIIIIIII/IIIII'I III/Illlllllld P. HEFTLER CARPET SWEEPER Feb. 21, 1950 3 Shegts-Sheet 3 Filed Nov. 26, 1941 Fae.

- RAJ/4W FIG. 54

Patented Feb. 21, 1950 UNITED STATES PATENT OFFICE 18 Claims.

The inventions described in this specification and shown in the accompanying drawings are improvements in carpet sweepers and particularly in high-low mechanisms for carpet sweepers. A fhigh-low mechanism, as the term is used by those in the carpet sweeper business, is a mechanism thatlowers the brush-of the carpet sweeper with respect to the case as the wheels rise with respect to the'case, so that, when the sweeper is resting on the floor and the case is pushed down by pressing down on the handle of the sweeper, the brush will move down faster than the case and come into contact with the surface to be swept sooner than if the brush were carried directly by the case.

The principal objects of these inventions are to provide high-low mechanisms that operate with less friction .than those nowin use and to provide high-low mechanisms that are cheaper to make than those now knownso that this type of mechanism can be put on even the lowest priced sweepers instead of being restricted, as they are now, to sweepers selling for $5.00 or more.

Other objects will be apparentfrom the following description and the accompanying-drawings,

in which:

Figure .1 is an end View, with a part of the end cover 8 broken away, of one design of carpet sweeperembodying some of the inventions;

Figure 2 is a bottom view, on a larger scale, of the mechanism shown in Figure 1;

Figure 3 is a section on the line 33 in Figure 1;

Figure 4 is a section on the line 4-4 in Figure 2;

Figure 5 isa section on the line 5-5 in Figure 4;

Figure .6 is a section on the line 6--6 in Figure 2;

Figure 'I is an end view, witha part of the end cover 58 broken away, of anotherdesign of carpet sweeper embodying some of the inventions;

Figure 8 is ,a, section approximately on the line 88 in Figure '7, 011a larger scale;

Figure 9 is a section on the line 9-9 in Figure -8;

Figure 10 is an end view of apart of a sweeper similar to the oneshown in (Figure 7 but modified in some details;

Figure 11 is a plan View and partial section of the parts shown in Figure 10;

Figure ,l2.is an end .view, with a part of the end cover I02 broken away, of another design of carpet sweeper embodying some of the inventions;

Figure 13 is a section .on the line 13-43 in Figure 1.2, on a larger scale;

Figure 1418 a section on the line I 4-44. in Figure 12 on the-same scale as Figure 13;

Figure 15 is .an end view of a part of a sweeper similar to the ,oneshown in Figure 12 but modified in some details; and

Figure '16 is .a section on the line l6l6 in Figure 15., on a slightly larger scale.

The sweeper shown in Figures 1 1306 In this sweeper, the wheels, brush, dust pans, handle, and main portion of the case areconventional. The :novel parts of the sweeper are the high-low mechanism, the end-covers of the case that carry the high-low ,mechanism, and the connections between the high-low mechanism and the brush and the wheels. However, all of the sweeper is illustrated in the drawings and is described below indetail in order that it will be quite clear how the novel parts of the sweeper are combined with the conventional parts .to form a highly integrated structure that is economical to manufacture and which works well.

The case and handle (Figures .1 to 3) The main part of the case I is formed by a pair of metal end plates '2 and 'a sheet metal memberS connecting the end plates together and forming the top and sides of the case. The top and *side member :3 is formed with flanges A at each end of the portion forming the top, and these flanges overlap the upper edges of the end plates :2 and are spot welded to them. The ends of the end plates 2 are bent out to form vertical flanges 5 almost but not quite in line with the portions of the top and side member thatform the sides of the case, and the side portions 6 are provided with extensions 7 that overlie the flanges .5 and that are also slightly out of line with the side portions 6.

.The "flanges 5 and the side extensions 1 are slightly out of line with the side portions 6 so that the flanged edges of the end covers 8 can .fit over them and :still lie flush with the main portions of the sides 6. Rivets 9 fix the end covers 8 to the flanges 5 on the end plates and to the side extensions I, and they also serve to fix'the flanges .5 and the side extensions T'toeach other.

The end covers 8 are generally .dome shaped and lit against the ends of the case I so as to form arsmooth streamline assembly, but each cover has a horizontally extending step or reentrant angle ID formed in it near the top. Above the angle .IU, the end cover has a short vertical portion l I out of which are punched two ears or lugs 1| 2, the lugs 12 extending towards each other on the inside of the vertical wall H of the end cover andicooperating with it to form a guide or slideway in which a portion of the high-low mechanism described below can slide up -and:down. Below the angle ID, the end cover bellies out to provide room for the operation of 3 other parts of the high-low mechanism, and it has two inwardly projecting bosses l3 on which the high-low mechanism is supported.

The case is encircled .by a conventional rubber bumper l4, which covers and conceals the depressions or hollows formed on the outside of the end cover 8 by the bosses l3 and which is held in place by clips l punched out of the end cover. The sweeper is operated by a conventional handle having a bail H which straddles the main part of the case I and whose ends IS are bent in to form trunnions fitting into bearings 13 in the end plates. Each end plate is formed with two bosses 23 above the handle bearing l9, the bosses being spaced apart and located so as toreceive the leg of the bail l! between them when the handle is vertical and to hold the bail and handle in that position. When the sweeper is to be used,

the handle is swung to one side or the other, and

the legs of the bail spring over the bosses and permit the handle to swing freely.

The case is provided with conventional dust pans 2 I, one at either side of the brush, and with conventional means for dumping them, but these are not illustrated or described in detail because their relation to the rest of the sweeper is the same as in the ordinary sweeper.

The wheels and axles (Figures 1, 2 and 4) Each of the four wheels of the sweeper is made of two

sheet metal discs

24 and 25 which lie in contact with each other over most of their area and which are secured together by four tubular rivets 26. The rivets 26 are formed integrally with the outer disc 24 and extend through holes and are clenched over the inner disc 25. The rims of the

discs

24 and 25 are formed intocylindrical flanges 27 and 28 with radially extending lips or

small flanges

29 and 33 at their outer edges, and a rubber tire 3i is seated on the

flanges

21 and 28 between the

lips

29 and 30.

The centers of the two

wheel discs

24 and 25 are shaped to fit around a ring of steel balls 32, and they thus form the outer race of a ball bearing. The inner race of the bearing is formed by a groove in a hub 33 which is mounted on an axle 34 extending through the case, the end plates 2 being formed with holes 35 through which the axles pass. Where the axles pass through the end plates, they are [provided with bushings 36 made of wood, plastic or other non-metallic material to prevent the sound made by the axles striking the end plates from being too tinny. The holes 35 through which the axles and bushings pass are large enough to allow them to move up and down three eighths of an inch or more and to move a similar distance across. The bushings 3B are formed with flanges that extend out over the holes 35, covering the holes and also preventing the bushings from sliding in on the axles.

The bushings 36 and wheel hubs 33 are sliding fits on the axles so that they can be easily assembled. They are held on by links 5'5 which interlock with the ends of the axles 34. Near each end of each axle, there are two notches 31 on opposite sides so that the cross-section of the axle at that point is as shown at 34 in Fig. 4. Each link 55 is formed of a flat piece of sheet metal with a long keyhole slot or hole 56 punched in it. The lower end of the hole 56 is large enough so that the round end of the axle can be slid through it to bring the notches 31 in line with the link, and the upper ,part of the hole is just wide enough to take the notched part of the axle. Thus the link cannot slide off of the end of the axle, and it holds the wheel on and also prevents the axle from turning and winding up on itself the threads that may be swept up by the brush and thrown up onto the axle. The lower ends of the links 55 are pivoted to the high-low brush adjusting mechanism, as described in detail below.

The brush (Figures 1 to 3) The brush assembly is built up on a wooden core 38 into which the tufts of bristles 39 are set in the usual manner in five or six wavy rows extending along the brush. Each end of the brush core 38 is necked down and extends out through a large notch in the end plate 2 of the case, and it carries a metal pulley or friction wheel 40 which lies between and is driven by the wheels and tires 3|. Each end of the brush core 38 also has a central hole 4| drilled into it to receive the bearing 64 which carries the brush and which forms a part of the high-low mechanism.

The high-low mechanism (Figures 1 to 6) The high-low mechanism is what adjusts the brush up and down with respect to the case as the case moves up and down with respect to the wheels, and it enables the sweeper to adjust itself to rugs and carpets of difierent thicknesses and softnesses and to bare floors. This mechanism includes a pair of dog-

legged levers

42 and and 43, which are fulcrumed or pivoted on shoulder rivets 44 fixed to the bosses l3 on the inside of the end cover. One of the two levers, the right-hand one 43, is shown on an enlarged scale in Figures 4 and 5 as well as in Figure 2, and it has one arm 45 that extends horizontally towards the axis of the brush and another arm 46 that extends down at an angle in the opposite direction. The sloping arm 46 has an end portion 4? bent in at right angles to its main portion, and the end portion 47, in turn, carries a tall 48 that extends straight down from its inner edge. The end portion 41 of the lever has a hole 49 through which one end of a rod spring is hooked, and an offset lug 50 projects in back of the spring near the fulcrum of the lever to keep the spring in a plane parallel to the general plane of the lever.

The horizontal arm 45 of the lever is offset to the outside, as shown in Figure 2, so that its end lies in the space provided by the bellying out of the end cover below the horizontal step If]. The end of the arm 45 is formed with a round hole in which is journaled a shoulder rivet 52 fixed to the brush pivot carrier described below. the other lever 42 is exactly symmetrical with the lever 43 which has just been described, one being a mirror image of the other, excepting that the hole 53 in the horizontal arm of the left-handed lever 42 is a horizontally extending slot, as shown in Figure 6, instead of being a round hole. This permits the shoulder rivet 54 which is journaled in it to not only turn with respect to the arm but also to slide 'back and forth a little. The

bent-in part 41 at the end of the sloping arm of each lever fits in the ground end of the slot 5'6 in one of the links 55, and the depending tail 48 on the end of the lever prevents the link from sliding ofi.

The spring 51 which hooks into the holes 49 in the end portions of the levers is one of the two main springs of the sweeper, there being one such spring at each end of the sweeper for each pair of wheels. The spring is made up of a horizontal enemas central portion and two depending leg portions joined to the central portion :by coils 58 and terminating in hooks 59, and it is supported entirely by the levers. Before it is assembled into the sweeper, its leg portions extend towards each other, approximately parallel to its central por tion, and overlap, so that, when it is in the sweeper, it tends to swing the sloping outer arms 46 of the levers towards each other. This causes the levers to pull down on the links and thus tends to force the wheels and axles down with respect to the case, transferring the weight of the case to the wheels.

The inner ends of the

levers

42 and 43 are connected to each other and to the brush through a brush pivot carrier '63, which is formed of a single E-shaped piece of spring metal, the back of the E extending horizontally and the three legs BI, 62 and 63 depending from it. The back or top of the carrier fill lies on the inside of the vertical part I! of the end cover above the step Ill, and it is held by the lugs l2 so that it can slide vertically. 'One outer leg 63 of the carrier has fixed to it the shoulder rivet 52 which is journaled in the round hole in the inner end of the right lever 43, and the lower part :of the carrier is thus guided in a fixed path. The other outer leg 6! of the carrier has fixed to it the shoulder rivet 54 which is journaled in the elongated hole .53 :in the inner end of the left lever 42, and the slight horizontal movement permitted by the elongated hole 53 prevents there being any fighting between the parts as they move up and down. The central leg 62 of the carrier has the brush pivot 64 riveted to it, the pivot fitting in the bearing 4| in the end of the brush and holding the brush 'in place.

The bellying out of the end plates 2 described above and the springiness of the brush pivot carriers permits the brush to be removed easily when it is necessary to comb threads and lint out of it. To remove the brush, the lower end of the central leg 62 of the carrier is pressed out with the thumb or finger of one'hand, thus partly withdrawing the brush pivot from the brush. The pivot is not entirely withdrawn by this operation because the end cover is not bellied out quite far enough to permit this, as it is not necessary. Complete withdrawal of the brush pivot is secured by placing two fingers of the other hand I on the outside of the brush pulley, one finger at either side of the brush pivot arm and pushing the entire brush towards the other end of the sweeper. This movement, which is permittedby the springiness of the brush pivot carrier :at

the other end of the sweeper and by the fact that the

outer legs

61 and 62 of the carrier and the arms of the levers to which they are connected are ofiset away from the brush, completely frees the brush from its pivot and allows one end of it'to be swung out of the sweeper. The other end of the brush "is then freed ;a similar way, and this completes the removal of the brush from the sweeper.

, In manufacturing and assembling :the sweeper, a certain procedure will be found to 'be most enicient. Certain sub-assemblies are first prepared, these sub-assemblies being '(1) the case complete with dust pans and their dumping mechanism but without the end covers 8 or the bumper lit,

(2) four wheels assembled with their tires and hubs, (3) two end covers 6, each with the 'two levers t2 and 43, the spring 51, and the :brush pivot carrier 60 and pivot :64 assembled .on :it;

and (4) the brush. In preparing the end cover f xiii) sub-assemblies, it is best to perform the following operations in the order given: '(1) rivet the brush pivot 64 to its carrier, (2) secure the carrier to one lever 43 .by the pivot 52, (3-) hook one end rof the spring to that lever and to the other lever 42, (4) place the lugs 50 on the levers bebind the legs :of the spring, (5;) secure thecarrier to the other lever 42 by their pivot '53, (6:) slide the upper end of the carrier 66 between and under the lugs 12 on the inside of the end cover, and I67) secure the levers to :the .end cover by their afulcrums 44L In the rfinal assembly of the sweeper, a link 55 is placed on one end :of each of the two axles, and the links are then Ihooked onto the end portions of the levers on one :end :cover assembly. A wheel assembly and a bushing 36 is then slid on each axle, and the case is then slid onto the axles into position on theend cover. Two more bushings 36 and the other two wheels are then slid onto the other ends of the axles, and two more links 55 are hooked into the notches on those ends of the axles. The foregoing is done with the sweeper standing on end, and it remains in that position during the next step in the assembly. The next step consists in taking a second end'cover assembly, placing it upright above the end of the sweeper and inserting the tails 480i the levers in the round ends of the holes in the links 55, and swinging the end cover down'onto the end of the sweeper. The rivets 9 which hold the end covers to the case are then put in, and the bumper i4 is put on. The handle bail H :can be sprung into place before the end covers are put on, or the end coverscan be :made with enough clearance at the top between their edges and the case to permit the bail to be sprung into place after the .end covers are put on- This completes the assembly.

The sweeper shown in Figures 7 to 9 Many of the parts of thissweeper, such as the case I, the bumper I4, the handle bail 11, the

wheel discs

24 and 25, the tires 3!, the ball bearings 32, the axle bushings v36, the brush 38-39, and the brush pulleys "40 are identical with the corresponding parts of the sweeper shown inFigures 1.1110 '6 and aretidentified'with the same numbers. The differences between the two sweepers are in the high-low mechanisms and in some of the parts to which the high-low mechanisms are connected.

In-the sweepershown in Figures 7 to 9, the end cover 58 is formed with :a pair of bosses 69 on the inside, on either side of the axis of the brush 38-39,.and the bosses 69 have riveted to them the fulcrums 1n and H of the high-low mechanism described below.

The hubs 12 of the wheels are drilled lengthwise to receive-the ends of the axles 13, but the holes for the .axles do not extend all of the way to the outer ends of the hubs; this keeps the axles 1313mm sliding out against the end cover 63. The outer ends ofthiehubs .12 project out beyond the sides of :the wheels, and each one is formed with a large groove '14 that extends around it. The bottom of each groove 14 is serrated across, so that this section of the hub 12 is like a gear with fine teeth, as.shown-in;Figure ,9. The serrations-at the bottom of the groove 14 can be made on ascrewzmachine at the sametime that the rest of the hub is machined by using a tool similar to a knurling tool.

The high-low mechanism (Figures 8 and! .Theihigh-lommechanism consists rof merely two 7. levers I6 and 11, their two fulcrums I and II, and a spring I8, and it is so simple that it adds only a few cents to the cost of the sweeper, thus making it practical for even the cheapest sweepers to be provided with a high-low brush adjusting mechanism.

The primary lever I6, which is the one to which the brush pivot I9 is riveted, is formed of a single piece of springy sheet metal. It has a body part 80 at the end away from the brush pivot I9, and three

arms

8 I, 82 and 83 extend from the body towards the brush pivot. The central arm 82 extends to just beyond the fulcrum I0 and is pivoted on it, and the other two arms SI and 83 curve together beyond the end of the central arm and have the brush pivot 19 riveted to them. The two outer arms 8! and B3, in reality, are a single arm divided into two over a part of its length to enable the entire lever I6 to be easily stamped out of one piece of sheet metal without any difficult forming operations.

The outer end or body part 80 of the lever is formed with a diagonal slot 84 that slopes down and away from the brush pivot 19 and that has small teeth 85 along its upper edge. The slot is wide enough so that the grooved part of the wheel hub I2 can slide freely in it past the teeth 85, and the teeth are of the right size and spacing to gear with the serrations at the bottom of the groove I4 in the hub when the hub is pressed against the upper serrated side of the slot.

The end of the central arm 82, beyond the fulcrum i0, is formed into a small tube 86 which tightly grips oneend of the spring 18, which is a piece of spring wire formed into two flat curlicues curling around the two lever pivots or fulcrums I0 and II. The part of the spring that fits in the tube 86 on the lever is straight, so that the tube 86 can be straight and easy, to make, but there is a sharp bend in the spring at each end of the tube to positively prevent the spring from sliding.

The other end of the spring is connected to the other lever TI in the same way as the first end is connected to the first lever I6. The other, or secondary lever, I1 is the same as the first lever 16 except for certain minor differences. Instead of having the brush pivot I9 riveted to it, the sec ondary lever has a slot 81 through which a neck on the brush pivot extends and in which it can slide back and forth a little as the levers swing up and down. The end of the lever 11 lies in the same plane as the rest of the lever, while the end of the primary lever I6 is offset a little from the plane of the rest of the lever 16 so that the main portions of the two levers can lie in the same plane while their ends overlap. Finally, the secondary lever I! has an ear 88 that projects down from the part that engages the brush pivot "I9 and which makes it easier to spring the levers out when the brush is to be removed.

The brush 3839 is removed by pinching the ear {:8 on the secondary lever 'II against the inside of the end cover 68 with one hand, which bends the levers 16 and 1! out and withdraws the brush pivot l9 halfway from its bearing M in the brush core, and at the same time pushing the brush towards the other end of the sweeper, which withdraws the brush pivot the rest of the way from its bearing. That end of the brush is then swung out, and the other end is freed in the same way.

When the sweeper is in operation, the wheel hubs I2 will tend to roll up to the upper ends of the oblique slots 84 in the levers, and this will.

force the wheels against the brush pulley 40 and provide the necessary traction between them. At the same time, the gear action between the teeth 85 on the edge of the slots and the serrations I5 in the bottoms of the grooves in the wheel hubs will positively prevent the wheel hubs or the axles from spinning with the wheels.

The way in which the sweeper is assembled during manufacture is obvious, except that the wheels are placed in the end covers, with their hubs engaged in the slots in the levers, and the assembly thus formed is then assembled to the case and axles.

A modified high-low mechanism (Figures 10 and 11) The high-low mechanism can be modified slightly, and perhaps made even cheaper to construct, by making the changes shown in Figures 10 and 11. The hub 33 of the wheel is made shorter, and the axle 9| extends clear through it and has its end 92 flattened to hold the hub 33 from sliding off. The oblique slot 93 in the lever 94 is made narrow enough to prevent the fiat end 92 of the axle, which fits in it, from turning but wide enough so that it can slide easily along it. In assembling this form of the mechanism, the wheels are placed on the axles and the ends of the axles are flattened, and then the end covers carrying the high-low mechanism are put in place.

The sweeper shown in Figures 12 to 14 This sweeper differs from those shown in Figures 1 to 11 in that its case IOI is of wood, its axles II9 rotate with the wheels H4, the wheels are of different construction, and the high-low mechanism is different.

The case (Figures 12 and 13) The main part of the case IOI is formed of a pair of end pieces I02, a pair of side rails or pieces I03 into which the end pieces I02 are rabbeted, and a single piece of thin curved plywood I04 forming the top and extending down over the outside of the side pieces I03. As may be seen in Figure 12, each side rail I03 is formed with a shallow rabbet I05 extending lengthwise along its upper edge, leaving a fiat surface below it to which the flat end of the piece of plywood is glued.

The case is completed by streamline metal end covers I09, which fit against the ends of the wooden case IIII and whose outer surfaces lie flush with and form smooth continuations of the outer surface of the plywood I04. The tops of the end covers I09 are formed with wide shallow notches which form slots at each end of the case IOI through which the handle bail I01 extends. Each end cover I09 is held in place by two screws III] extending into the end I02 of the wooden case, and spacing tubes or sleeves I I I are provided around the screws IIO between the case end I02 and the parts of the end cover I09 through which the screws pass so that the screws may be turned up tight without bending the end cover.

The heads of the screws IIO lie in shallow recesses in the end cover, and they are covered by the conventional rubber bumper II2 which encircles the sweeper. The bumper II2 may be supported by clips formed out of the end cover, as in the sweepers shown in Figures 1 to 11, or it may be nailed to the wooden case IOI. The bumper II2 also conceals, although it does not -.75 cover, an opening I45 in the center or the end "c eeses cover Its just above its lower edge. Theilo'wer edge of the openingllli is strengthened by an inwardly extending flange, and it serves as a ful crum for a screw-driver or otherleve'r' used in removing the brush as described below.

The wheels and axles (Figure 14) Each wheel is formed: of a single disc of sheet metal II4 having a flange II5 which forms its rim and on which a rubber tire I I6 is cemented. The center of the disc I-I4 is stifiened by a Washer H8 and is riveted to ahub I I1, which is a sliding fit on the axle H9. The axle I I9 extends through the case I III, and the part within the case is enclosed by an axletube I08: so that threads picked up by the sweeper will not become wound up on the axle, which turns with the wheels.

The axle tubes I08 are fixed in the ends 632 of the case, and they are'large enough to permit the wheels I I4 and axles IIS-to move up and down I freely with respect to the case Ifll as the sweeper adjusts itself to the surface being swept. The ends of the axle tubes I081 are covered by washers I2I carried by the axles between the wheels and the ends I02 of the case, and the keep the inner ends of the wheel hubs from hooking into the axle tubes and keep the wheels from moving in towards the case. Accidental outward movement of the wheels is prevented by antifriction wheelsior rollers: I35, forming parts ofthe high-10w mechanism and engaging the axles no just outside of the wheel hubs I I'Land accidental outward movement of the axles H9 is prevented by spring brackets I30, which carry the high-low mechanism and lie just The brush (Figures 12 and 1-3)- The brush assembly is similar to that in" any conventional sweeper and consists of a brush core I22, bristles. I'23'set into the brush core; and a pulley I24 On each end of the brush core". The core I22 is preferablyof wood, forcheapness, and has a hole I25 in each end which form'sa bearing for the brush pivot I33; The'pull'eyl24 may be of metal; like. the pulley shown in Figure 3', or of wood" or plywood, or of wood covered'with a metal rim.

The high-Zowmechanism (Figures 12 to 14) The high-low mechanism is" formed of two levers I26 and I21'which arepivot'ed-on shoulder rivets I28 and I29' carried by a spring bracket I30. One lever I26; called the primary lever, has the brush pivot I33 riveted to an arm I32 which extends approximately horizontally from the pivot or fulcrum I 28. Another arm I34- of the primary lever curves around over the axle H9 and carries an anti-friction wheel I35 on a shoulder rivet I36 which forms its bearing, the antifriction wheelbeing located so that it rideson the upper and outer side of the axle right next to-the end of the wheel'hub I I1. The anti -fr-iction wheel I35 presseson theaxle H8 at-an angle of about 45 tothe vertical, and it thus holds the wheel I1 5 and axle H9 pressed towards'the brush' pulley I24 as well as towardsthefloor.

The diameter of: the anti-friction": wheel I35= is several times as -great as. the diameter of: the axle I I9 upon which it rolls. Hence, the anti-friction wheel: I35 will turn at a speed which is only a small fractioniof the speedof'the floor wheel H5, and the frictioniwilL be only a small fraction of what it wouldbe'if the floor wheel turned on its axle.

The primary 'lever I26 also includes-an arm I31: which extends down below the level'oi the fulcrum I28 almost to" the lower edge'of the end washers I2 I at the ends oi the axles.

rangement is such that cover I09 of the case and which terminates in a short outwardly bent end I38 with a hole in it. The secondary lever I21 is similar in every way to the primary lever I28, except that its horizontal arm MI) is oiTset alittle to one side so that it will lie alongside of the horizontal arm I26 of the primary lever, and it has a slot through which the brush pivot I33 passes instead of having the brush pivot riveted to it.

Aspring M2 is hooked intothe holes inthe lugs I38 and I39 on the two levers, pulling the lugs towards each other and causing the levers and their anti-friction wheels to press down on the axles of'the'fioor wheels H5. The spring I42 may be identical with the: spring 5T ofthe sweeper shown in Figs. 1 to 6, but it is preferably a simple coil spring stretched between the lugs I38 and I39 and having coils near each end and a straight wire part I43 in the center so that it will be less inthe way when the brush is being removed.

The spring bracket I38 is formed of a strip of springy' steel, and it is held in place by having its ends clamped under the ends of the spacing sleeves III on the end cover screws III). At the center of the sweeper, the spring bracket I30 passes just above the level of the hole I45 near the bottom of the end cover I89 and is spaced in a short distance from the end cover. The ara screwdriver can easily be inserted intothe hole I 65 andunder the: center of the lower edge of the spring bracket I30, and the spring bracket can be Dried out far enough to more than half withdraw the brush pivot I33 from its bearing. I25 in theend of the brush I22. At the same time, the brush can be pushed towards the other end of the sweeper by pressing on'the side of the brush pulley I23, this movement of the brush being permitted by the flexing of the spring bracket at. the other end ofthe sweeper, and thus freed entirely from its pivot I33. The other end of the brush can then be freed in a similar way,. and the entire brush removed from the sweeper.

A- modified high-low mechanism (Figures 15' and 16) The high-low mechanism can shown in Figures 15 slightly less material,

Ice-modified, as and 16, so as to require although at the expense of requiring more complicated and expensive dies. In this modification, the lever I48 has an arm I49 that slopes down from the fulcrum I28 andcarries a pivot Iii) for the anti-friction wheel I5I at a point below and in towards the center of the sweeper from the axle I52. The antifriction wheel EBI is cup shaped and has an inturned rim I53 which bears on the upper and outer side of the: axle I 52, the axle projecting into' the hollow side of the anti-friction wheel. The center of the anti-frictionwheel I5 I'is bossed in so that the bearing IEI} will lie in the plane of the rim I53 upon which the loadis carried.

The hub I52 of the floor wheel I55" is a trifle shorter than the hub II? of thefloor wheel '4 of the sweeper shown in Figures 12'to l4, and the axle I52 is a little shorter, but the construction is otherwise the same. The same type of spring may be used, and it hooks into a hole P56 in an outwardly projecting ear IE?- on the end of the arm I49 of the lever.

The sweepers described above incorporate not only a single invention but several inventions; and they may be carried out not only as shown but inmany other ways, some of which may even involve further invention, The inventions: de

scribed here therefore include any construction or device falling within the terms of any one ofwheels move up with respect to the case, there being only one connection between the high-low mechanism and each wheel, and each of these connections being constructed and arranged to press the wheel down and in towards the brush pulley at an angle of approximately forty-five degrees to the vertical so that the portion of the pressure transmitted by this connection and pressing the wheel against the brush pulley is great enough to prevent the floor wheel from slipping on the brush pulley.

2. A carpet sweeper as defined in claim 1 and in which the connections between the high-low mechanisms and the wheels include slots that are inclined down and out at angles of about fortyfive degrees to the horizontal.

'3. A carpet sweeper as defined in claim 1 and in which the connections between the high-low mechanisms and the wheels are rollers which are carried by the levers and which roll on the upper and outer sides of the axles of the wheels.

4. In a floor and carpet sweeper having wheels and a brush and a case and a handle pivot, mechanism connected to the wheels and the brush and the handle pivot for moving the brush down relative to the handle pivot when the handle pivot is moved down relative to the wheels, the only connection between that mechanism and each of the wheels being a means for guiding that wheel relative to the adjacent portion of the mechanism in an oblique path extending up and towards the axis of the brush at an angle of approximately forty-five degrees to the horizontal.

5. A mechanism as defined in claim 4 and in which the wheel has an axial projection and in which the connection to the wheel is a roller that bears on the axial projection.

6. In a fioor and carpet sweeper having a case, a rotary brush with one or more friction pulleys thereon, one or more wheels adapted to roll on the floor and engage the friction pulleys and thereby drive the brush, and a handle pivot hearing fixed to the case, the combination of a mechanism connected to the wheels and to the brush and to the handle pivot bearing and constructed and arranged to move the brush down relative to the handle pivot bearing when the handle pivot bearing is moved down relative to the wheels, and a single connection between said mechanism and each of the wheels, each of said connections being obliquely movable and constructed and arranged to press its wheel against one of the brush pulleys as hard as it presses its wheel down.

7. A carpet sweeper of the character described comprising a casing, floor wheels for the casing, floating axles for the fioor wheels, a brush, brush pivots on which the brush is supported for rotation and for vertical shifting movement, and spring means comprising a spring carried by and acting on oppositely extending vertically rigid levers located at each end of the casing and having their inner end portions interconnected with and pressing downwardly on the brush through the brush pivot, their outer end portions interconnected with and pressing inwardly and downwardly on the floor wheels, and their central portions intermediate the points of interconnection with the brush and the fioor wheels fulcrumed on a fulcrum support member mounted on the casing whereby said spring means functions to transmit upward and downward movement of the floor wheels to the brush while reversing the direction of such movement, portions of said spring means and said fulcrum support member being laterally springy enough and free to move out from the casing just enough to withdraw the brush pivot at least halfway but not all of the way out of the brush.

8. A carpet sweeper having a case, a handle pivoted on the case, a rotary brush in the case, pivots on which the brush can rotate, friction pulleys on the ends of the brush, wheels that can roll on the floor or carpet and drive the brush through the friction pulleys, and high-low mechanisms for moving the brush pivots and the brush down with respect to the case when the wheels move up with respect to the case, the only connection between the high-low mechanism and each wheel being a link extending up and away from the axis of the brush at an angle of approximately forty-five degrees to the horizontal.

9. In a carpet sweeper having a case and an axle, a connection from the case to the axle including a small wheel rolling on the upper outer side of the axle.

10. In a carpet sweeper having a case, a rotary brush in the case, friction pulleys on the ends of the brush, brush pivots projecting into the ends of the brush, wheels that can roll on the carpet and drive the brush through its friction pulleys, and end covers fixed to the ends of the case and enclosing the ends of the brush and the friction pulleys and the wheels, the improvement which consists of fulcrums on the end covers between the axes of the brush and the wheels, and springy brush-adjusting levers mounted on the fulcrums inside of the end covers and connected to the wheels and the brush pivots for moving the brush down when the wheels move up, each of the brush pivots being fixed to the inner end of one lever and having a pin-and-slot connection with the inner end of another lever, and there being just enough clearance between the inner ends of the levers and the end covers and the levers being springy enough so that their inner ends can be sprung out towards the end covers far enough to move each brush pivot out a distance equal to at least half but not all of the distance that it normally projects into the end of the brush, whereby either end of the brush can be freed from its pivot by simultaneously springing that pivot towards the adjacent end cover and springing the brush and the other brush pivot towards the other end cover, and the brush can then be removed by swinging its free end out of the case and moving the brush endwise away from the other brush pivot.

11. A carpet sweeper as defined in claim 10 and in which each lever has two independent arms extending one to a fulcrum and the other to the brush pivot, the two arms extending in the same general direction from where they join together so that one of the arms is longer than the distance from the fulcrum to the brush pivot 12. A carpet sweeper as defined in

claim

10 and 13 in which each of the levers has a slot which slopes down and out and through which it is connected to one of the wheels.

13. In a floor and carpet sweeper having wheels and a brush and a case, levers connected to the wheels and the brush and pivoted on the case for moving the brush down relative to the case when the case is moved down relative to the wheels, the only connection between the levers and one of the wheels being a means for guiding the wheel relative to the lever in an oblique path extending up and towards the axle of the brush at an angle of approximately forty-five degrees to the horizontal.

14. In a carpet sweeper having a brush pulley located between and driven by frictional contact with a pair of floor wheels, a pair of fulcrums on a fixed part of the sweeper, one fulcrum being located between the axes of the brush pulley and one of the wheels and the other fulcrum being located between the axes of the brush pulley and the other Wheel, lever mechanism extending between and beyond the fulcrums and connected to the fulcrums, the lever mechanism being constructed and arranged to bend up and down in its central portion between the fulcrums, means connecting the central portion of the lever mechanism to the brush pulley for moving it up and down, and means connecting the outer portions of the lever mechanism to the wheels, the last men- :3

tioned means including axle members on which the wheels are mounted and surfaces on the outer portions of the lever mechanism extending down and out at angles of approximately forty-five degrees to the horizontal and slidably engaging the axle members so as to transmit forces between the lever mechanism and the wheels along lines sloping down and in below the brush pulley at a great enough angle to the vertical to intersect a short distance below the brush pulley and to force the wheels against the brush pulley hard enough to prevent slipping between them when the sweeper is in use.

15. A carpet sweeper of the character described comprising a casing, floor wheels for the casing,

floating axles for the floor wheels, 2. brush supported for rotation and for vertical shifting move ment, and spring means at each end of the casing and having portions interconnected with and pressing downwardly on the brush, portions interconnected with and pressing inwardly and downwardly on the floor wheels, and portions intermediate the points of interconnection with the brush and the floor wheels fulcrumed on the casing whereby said spring means functions to transmit upward and downward movement of the floor wheels to the brush while reversing the direction of such movement, the spring means comprising two levers and a spring carried by and interconnecting the levers, and the portions of the spring means interconnected with the floor wheels being parts of the levers lying above and outside the axes of the wheels and pressing downwards and inwards on the wheels.

16. A carpet sweeper of the character described comprising a casing, floor wheels for the casing, floating axle members for the floor wheels, a brush supported for rotation and for vertical shifting movement, and spring means at each end of the casing and having portions interconnected with and pressing downwardly n the brush, portions interconnected with and pressing inwardly and downwardly on the floor wheels, and portions intermediate the points of interconnection with the brush and the floor wheels fulcrumed on the casing whereby said spring means functions to transmit upward and downward movement of the floor wheels to the brush while reversing the direction of such movement, the spring means comprising two levers and a spring carried by and interconnecting the levers, and the portions of the spring means interconnected with the floor wheels being parts of the levers bearing upon the upper and outer sides of the axle members and movable relative to the axle members along paths intersecting above the axis of the brush.

17. A carpet sweeper of the character described comprising a casing, fioor wheels for the casing, floating axle members for the floor wheels, a brush supported for rotation and for vertical shifting movement, and spring means at each end of the casing and having portions interconnected with and pressing downwardly on the brush, portions interconnected with and pressing inwardly and downwardly on the floor wheels, and portions intermediate the points of interconnection with the brush and the floor wheels fulcrumed on the casing whereby said spring means functions to transmit upward and downward movement of the floor wheels to the brush while reversing the direction of such movement, the spring means comprising two levers and a spring carried by and interconnecting the levers, and the portions of the spring means interconnected with the floor wheels being parts of the levers engaging the axle members and preventin them from rotating freely.

18. A carpet sweeper of the character described comprising a casing, floor wheels for the casing, floating axle members for the floor wheels, a brush supported for rotation and for vertical shifting movement, and spring means at each end of the casing and having portions interconnected with and pressing downwardly on the brush, portions interconnected with and pressing inwardly and downwardly on the floor wheels, and portions intermediate the points of interconnection with the brush and the floor wheels fulcrumed on the casing whereby said spring means functions to transmit upward and downward movement of the floor Wheels to the brush while reversing the direction of such movement, the spring means comprising two levers and a spring carried by and interconnecting the levers, and the interconnections between the spring means and the wheels being formed by rollers that are carried by the levers and bear on the axle members.

PAUL HEF'I'IER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 388,376 Ru Ton Aug. 21, 1888 600,413 Drew Mar. 8, 1898 933,893 Deacon Sept. 14, 1909 2,011,261 Pullen Aug. 13, 1935 2,059,907 Pullen Nov. 3, 1936 2,068,943 Callan Nov. 26, 1937 2,171,633 Pullen Sept. 5, 1939 2,210,953 Replogle Aug. 13, 1940 2,226,581 Richardson Dec. 31, 1940 2,228,528 Miller Jan. 14, 1941 FOREIGN PATENTS Number Country Date 441,175 Great Britain of 1936