US3881535A

US3881535A - Stairholding device for vacuum cleaner

Info

Publication number: US3881535A
Application number: US360149A
Authority: US
Inventors: Bois Jean P Du; Roger A Rieckman
Original assignee: Sunbeam Corp
Current assignee: Sunbeam Corp
Priority date: 1973-05-14
Filing date: 1973-05-14
Publication date: 1975-05-06
Anticipated expiration: 1992-05-06
Also published as: FR2229373A1; US3820808A; GB1441605A; AU6878074A; GB1460359A; FR2229373B1; FR2229587A1; FR2229587B1; AU6878174A

Abstract

A mechanism for holding a canister or tank type vacuum cleaner in an inclined position on a stairway is disclosed. A pair of spring biased pawls are provided on the under side of the vacuum cleaner to cooperate with the rear wheels of the vacuum cleaner which are constructed with a number of cavities in the inner portion of the wheel. The pawls and wheels provide a ratchet-like engagement such that forward rotation of the rear wheels is possible, but rearward rotation is prevented. A pair of control arms are mounted in the pawls so that they may be locked in a retracted position so that the stairlocking mechanism may be disengaged when desired.

Description

United States Patent [1 Du Bois et al.

[ May 6,1975

[ STAIRHOLDING DEVICE FOR VACUUM CLEANER [75] Inventors: Jean P. Du Bois, Villa Park; Roger A. Rieckman, Elmhurst, both of I11.

[52] US. Cl. 15/327 E; 15/339; 74/578;

188/829 [51] Int. Cl A471 9/00 [58] Field of Search 15/327 R, 327 A, 327 B,

15/327 D, 327 E, 339; 188/31, 82.9; 280/1.l82, 5.2, 5.26; 74/575, 578

205,968 2/1957 Australia 15/327 R Primary Examiner-Harvey C. I-Iornsby Assistant ExaminerC. K. Moore Attorney, Agent, or FirmGeorge R. Clark; Neil M. Rose; John S. Pacocha [57] ABSTRACT A mechanism for holding a canister or tank type vacuum cleaner in an inclined position on a stairway is disclosed. A pair of spring biased pawls are provided on the under side of the vacuum cleaner to cooperate with the rear wheels of the vacuum cleaner which are constructed with a number of cavities in the inner portion of the wheel. The pawls and wheels provide a ratchet-like engagement such that forward rotation of the rear wheels is possible, but rearward rotation is prevented. A pair of control arms are mounted in the pawls so that they may be locked in a retracted position so that the stairlocking mechanism may be disengaged when desired.

8 Claims, 5 Drawing Figures 4-f- 5 65 76 if PJJENTEUMY saws 1,535

SHEET 10F '2- STAIRHOLDING DEVICE FOR VACUUM CLEANER BACKGROUND OF THE INVENTION Tank type or canister vacuum cleaners are conventionally made with some form of wheels, skids or rollers which facilitate moving the tank from one place to another while the cleaning operation is being performed. These wheels, skids or rollers function well on carpeting or hard surface floors as long as use is being restricted to a level surface.

The canister or tank type cleaner is designed for or adapted to cleaning the carpeting or hard surface of strairways. The house conventionally associated with a tank type cleaner is usually of such limited extent that normally a stairway cannot be cleaned without supporting the cleaner on the stairway itself. Depending on the size and shape of the cleaner, it may possibly be able to rest it on one of the steps of the stairway. In general, however, a tank type vacuum cleaner is large enough so that it cannot be conveniently positioned on a single step of a stairway. Even if the cleaner may be so positioned, it tends to completely block or at least obstruct the stairway and prevents the user of the cleaner from mounting or descending that portion of the stairway while cleaning the steps. The skids, wheels and rollers associated with the tank or canister vacuum cleaner often increase the problems in temporarily storing the cleaner on a step while vacuuming the stairway since they tend to facilitate the tanks sliding off of the step on which it is resting.

There is shown in the prior are DesCarries U.S. Pat. No. 3,015,123, a retractable leg or lever which may be used to retain a tank type cleaner in an inclined position in the middle of a stairway. The structure shown in the DesCarries patent to accomplish this function of holding the cleaner on the stairway is complicated and difficult to operate. It would be desirable, therefore, to provide a simple and effective means for retaining a tank type vacuum cleaner in an inclined position on a stairway.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates, in general, to a mechanism for holding vacuum cleaners on a stairway in an inclined position and more particularly, relates to a locking mechanism which may be either selectively disengaged or selectively put into an operative condition whereby the mechanism will be automatically engaged to prevent rearward mmovement of the vacuum cleaner.

A pair of spring biased pawls are provided on the bottom of the vacuum cleaner housing to cooperate with the supporting wheels of the cleaner in forming a ratchet mechanism which allows the wheels to rotate in the direction but prevents them from rotating in the rearward direction. The inside of the wheels are formed with peripherally disposed notches in which the ends of the pawls are received to provide this ratchet action. The wheels with which the pawls cooperate are positioned at the rear end of the vacuum cleaner and are large enough to prevent the vacuum cleaner from sliding downwardly along the front edges of the stair treads when the cleaner is supported in an inclined position on the stairs.

The pawls may be manually retracted against a spring means which cooperates in urging the pawls into en- LII gagement with the wheels. When in this retracted position, the pawls may be locked so that the ratchet action will be prevented. This permits the housewife to lock the wheel locking mechanism out of action until she intends to vacuum a stairway, at which time the pawls are again released.

Accordingly, it is an object of the present invention to provide an improved vacuum cleaner having means for restraining the cleaner from downward movement when it is located in an inclined position on a stairway.

It is a further object of the present invention to provide a vacuum cleaner having wheel supporting means which may be locked against rotation in one direction so that the cleaner may be prevented from downward movement onastairway through the engagement of the wheels with thetreads of the stairs.

It is another object of the present invention to provide a tank type cleaner having an improved mechanism for retaining the vacuum cleaner in an angled position on a stairway, which mechanism may be locked in an inoperative position.

It is a further object of the present invention to provide an uncomplicated, quick acting, wheel-licking mechanism for a wheeled vehicle such as a canister or tank type vacuum cleaner in which the locking mechanism comprises one or more pawl members which are mounted on the bottom of the housing and which are biased outwardly towards the wheel of the vehicle wherein there are a number of cavities on the inner side of the wheel which interact with the outwardly biased pawl so as to allow rotation of the wheel in one direction and to prevent rotation of the wheel in the opposite direction.

Other objects and advantages of the present invention will be apparent to those skilled in the art from the following specification including the drawings and the claims.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a canister vacuum cleaner which employs the stair-locking mechanism of the present invention, the vacuum cleaner being shown in an inclined position on the stairway;

FIG. 2 is a rear view of the canister vacuum cleaner of FIG. 1 which shows a partial cut-away section view of the locking mechanism of the present invention;

FIG. 3 is a fragmentary sectional view of the vacuum cleaner taken on line 3--3 of FIG. 2;

FIG. 4 is a fragmentary sectional view taken on line 4-4 of FIG. 2;

FIG. 5 is similar to FIG. 4 but showing the stairlocking mechanism in the disengaged position.

TECHNICAL DESCRIPTION OF THE INVENTION A vacuum cleaner embodying the present invention is shown in FIG. 1 and is designated generally by reference numeral 20. The vacuum cleaner 20 has a front cap 22 and a rear cap 24 which form the ends of the elongated canister tank 26. The tank 26 is constructed of two channel shaped steel members which are joined together at their edges to form a tubular member. The junction of the two members is covered by soft plastic bumpers 28, which are preferably extruded of polyvinyl chloride and are mounted on the sides of the tank 26 to protect furniture.

Mounted on the top surface 30 of the tank 26 is a tool holding and handle assembly 32 and a hose holding wall section 33. The front cap 22, the rear cap 24 and the tool holding and handle assembly 32 and the hose holding wall section 33 are all formed of plastic, preferably of a high impact polystyrene. The tool holding and handle assembly 32 consists of a number of upwardly projecting tool holding posts which support various tools and accessories which may be used with the vacuum cleaner. The tool holding and handle assembly 32 also comprises a handle 34 so that the entire vacuum cleaner may be lifted by the handle if desired. The hose holding wall section 33 is constructed with the pair of

elongated sidewalls

35 and 37 which slant slightly outwardly.

A flexible hose assembly 38 is coupled to the intake of the vacuum cleaner in the front cap 22. The front cap 22 may be opened to allow for the replacement of dust bags when it is necessary to do so. For the purpose of opening the front cap 22, a latch 39 is provided on the upper surface 30 of the tank 26.

The rear end cap 24 houses a cord reel on which is stored a power cord having a plug 40 which extends upwardly through a grommet member in upper surface of the rear end cap 24. The upwardly extending plug 40 eliminates a particularly annoying feature of many cord reel vacuum cleaners which is caused by a tendency of the operator to pull the vacuum cleaner around when the cord is being extended. Since the pulling force on the plug 40 is in a vertical direction, the weight of the vacuum cleaner tends to oppose the pulling force and the vacuum cleaner will not be pulled from its position by the operator.

A large front swivel castor 41 is employed to allow for substantially effortless movability of the cleaner. A pair of large rear wheels 42 are positioned at the rear end of tank 26 with one wheel on each side. The wheels 42 are made of high impact polystyrene and include polyvinyl chloride tires 43 used to provide for easy rolling either over low or high pile carpets. The wheels 42 are, therefore, quiet and non-marring when they roll over bare floors and are supported by an axle 44, which is supported in plastic portions 45 formed integrally with cap 24 as is best shown in FIG. 3. A more complete description of the vacuum cleaner of FIG. 1 may be found in co-pending application, Ser. No. 270,421, which is assigned to the assignee of the present invention.

As has been indicated above, it is conventional for tank type vaccum cleaners to include some type of skids, rollers or wheels so that they may be moved from room to room while the vacuum cleaning is being performed. Because of the weight and shape of the tank type vacuum cleaner and the nature of these skids and rollers, such a vacuum cleaner will normally slide down stairs if positioned in an angled or inclined position on the stairs. Accordingly, if the user of the vacuum cleaner wishes to vacuum the stairs, he may either hold the tank continuously or attempt to balance it on one of the steps. Although there has been at least one prior art attempt to provide a means for locking the vacuum cleaner against downward movement on the stairs, this attempt involved the provision of an additional mechanism to the skids, which support the vacuum cleaner for horizontal movement. In order to simplify the structure for locking the vacuum cleaner in an inclined position on the stairs, we have conceived a mechanism which includes large wheels located at the rear end of the vacuum cleaner and means for braking or locking these wheels against rearward movement. The size of the wheels is, of course, important since the locking of the conventional small wheels or rollers found on vacuum cleaners would be ineffective in arresting the downward movement of a vacuum cleaner when in an inclined position on the stairs. If the retaining mechanism is to operate properly, it should be possible for the user of the vacuum cleaner to merely pull the cleaner up the stairs and when it is released at a desired position, the cleaner will move a relatively short distance until the locking mechanism engages and becomes effective. It is important that the locking mechanism be quick acting so that the vacuum cleaner does not attain substantial momentum before being restrained.

The large wheels 42 of the present invention are located well to the rear of the tank 26 and extend a substantial distance below the bottom of the tank 26 so that the wheels engage over a substantial portion of the tread of the stairs as can be best seen in FIG. 1. The stairlocking mechanism of the present invention consists of means for locking the wheels 42 against rearward movement so that the vacuum cleaner 20 as positioned on the stairs in FIG. 1 will be restrained against sliding down the stairs.

For the purpose of restraining the wheels 42 against counterclockwise movement as shown in FIG. 1, there are provided a pair of pawls, 50 and 52, each of which has a sloping

cam surface

50a and 52a on its outer end. The

pawls

50 and 52 are supported for lengthwise sliding movement in a tubular enclosure 54. The enclosure 54 is secured to a mounting plate 55 which is assembled to the bottom of end cap 24 by mounting bolts 58.

Each wheel 42 is formed on its inner face with an annular groove 42a (See FIG. 3) which is divided into 18 separate recesses or pockets 42b by radially extending partitions or walis 42c. As is evident from FIG. 3, every third partition 42c is provided with a partition 42d extending to the central hub 42e of wheel 42 to increase its rigidity.

The

pawls

50 and 52 are preferably formed of a solid metallic material and include inner ends 50b and 52b which each support radially extending control arms and 62. The

arms

60 and 62 are threadedly received in holes 64 formed in the ends 50b and 52b. The

control arms

60, 62 serve to limit the outward travel of

pawls

50, 52 under the influence of a coil spring 68 which is located within the tubular member 54 between the

pawls

50, 52. The

control arms

60, 62 are adapted to move axially and peripherally with respect to member 54 within L-shaped

slots

76 and 78 respectively. In normal use, the

pawls

50, 52 move lengthwise of a member 54 with the

control arms

60, 62 moving in lengthwise extending portions 760 and 78a of the

slots

76 and 78. In the outermost positions of

pawls

50, 52 as shown in FIG. 4, the

control arms

60, 62 engage the ends of

portions

76a and 78a positioning the outer ends of

pawls

50, 52 extending into pockets 42b.

If the wheels 42 are rotated so as to move the vacuum cleaner in the reverse direction, the inner edge of one of the walls 420 will abutt against the outer end of each of the

pawls

50, 52 preventing continued rotation of wheels 42. Since the force exerted by the wheels 42 in this instance is in a direction normal to the axis of the

pawls

50 and 52, they will not be forced axially within enclosure 54 and they will thus effectively lock the wheels 42 against further rotation. The vacuum cleaner 20 is thereby prevented from sliding down the stairs in the reverse direction when the vacuum cleaner is positioned at an incline on the stairway.

In order that the

pawls

50, 52 not restrict rotation of the wheels 42 in the forward direction, the ends of the

pawls

50, 52 are angled at 50a and 52a as shown in FIGS. 2, 4 and 5. The angled ends 50a and 52a cam the pawls inwardly as they are engaged by the walls 420 when the wheels 42 are rotated forwardly or clockwise as shown in FIG. 1.

If the operator merely wishes to move the vacuum backward and forward on a level surface or to pull the vacuum cleaner up the stairway or lower it down in transport and does not desire to stop on the stairway to clean it, the wheel-locking mechanism can be disengaged. The manner by which this is achieved is best shown by reference to FIGS. 4 and 5. In order to disengage the wheel-locking mechanism, the

arms

60 and 62 are squeezed together thereby compressing the springs 68. When the

arms

60 and 62 reach the inner ends of the

portions

76a and 78a of

slots

76 and 78 respectively, they are rotated into a horizontal position moving into the portions 76b and 78b as shown in FIG. 5. The

pawls

50 and 52 are thereby locked out of engagement with wheels 42 or into a nonfunctioning position. In order to re-engage the wheel-locking mechanism, the

arms

60 and 62 are rotated downwardly into the

portions

76a and 78a of

slots

76 and 78, thereby allowing the spring 68 to again force the

pawls

50 and 52 outwardly to engage the walls 42c of the wheels 42.

From the description presented above, the operation of the

pawls

50 and 52 in connection with the preventing reverse rotation of the wheels 42 should be evident. In understanding exactly how the vacuum cleaner with the wheel-lock mechanism operates on the stairs, reference should be made to FIG. 1. Under normal conditions, the user of the vacuum cleaner moves it along the floor and up the stairs by pulling it with the flexible hose 38. If the stairs are being cleaned, the user of the vacuum cleaner would merely pull the vacuum cleaner 20 up the stairs until he arrived at a suitable location from which most of the stairs could be reached considering the length of hose 38. As this location is reached and the forward force exerted on the hose 38 is released, the wheels 42 might not even be in contact with one of the stair treads. If that were the case, the vacuum cleaner 20 would necessarily have to slide downwardly for at least a brief period until the wheels 42 would engage the tread of one of the stairs. Because of the limited size of the pockets 42b within which the

pawls

50 and 52 are received, the wheel could rotate less than 20 before it is restrained against further reverse rotation. The size of the wheel, the location of the wheel, and the amount of rotation before the locking action becomes effective are all important factors in whether or not the vacuum cleaner will be properly restrained against downward movement, particularly, when the operator releases the vacuum cleaner in such a position that it has an interval of time to gain momentum before the wheel-locking mechanism is actuated. In one preferred embodiment, the wheels 42 are 4 /2 inches in diameter and project 2% inches below the underside of the tank so that the wheels 42 will engage over a substantial portion of the tread of each stair. This assures that the vacuum cleaner 20 will not have an opportunity to gain enough momentum that it will bounce over each of the succeeding treads, even though the wheels might be locked against reverse rotation.

By providing a mechanism for locking a vacuum cleaner in position on the stairs, which adds only the pawl mechanism in cooperation with the cleaner supporting wheels, it provides a very simple and inexpensive means for accomplishing a necessary and desirable function. In addition, the control arms for locking the mechanism in an inoperative position are extremely simple and add little to the cost of the mechanism. It is, however, desirable to permit the user of the vacuum cleaner to be able to render the wheel-locking mechanism inoperative since there are many occasions in which the vacuum cleaner may be moved in a reverse direction when it is being guided about in normal use.

Although a particular embodiment of the present invention has been described, it is not intended that the present invention be limited to a particular embodiment illustrated herein since variations and modifications thereof will be apparent within the scope of the present invention to those skilled in the art.

What is claimed as new and desirable and desired to be secured by Letters Patent of the United States is as follows:

1. A household vacuum cleaner comprising an elongated housing having a front end from which a suction hose extends and a rear end, front wheel means and rear wheel means at said front end and at said rear end respectively, brake means mounted on said housing adjacent said rear wheel means to prevent rotation of said rear wheel means when said vacuum cleaner is in an inclined position on stairs, said rear wheel means engaging the tread of a stair to prevent said vacuum cleaner from sliding down the stairs, said rear wheel means comprising a pair of spaced wheels mounted on a fixed axis positioned adjacent the lower rear edge of said housing, said suction hose being adapted to drag said cleaner forwardly including up stairs, said brake means locking at least one of said rear wheels against rotation in a first direction preventing rearward movement of said cleaner while permitting rotation in the opposite direction to provide forward movement of said cleaner.

2. The vacuum cleaner of claim 1 wherein said wheels extend outwardly from said housing to engage a stair tread substantially inwardly from the outer edge of the tread when the cleaner is in an inclined position on stairs to effectively brake the cleaner against downward sliding movement.

3. The vacuum cleaner of claim 1 wherein said wheel brake is activated by rotation in said direction and said actuation is produced with less than a 30 rotation of said wheels.

4. The combination of claim 1 wherein said brake means engages with at least one of said rear wheels and comprises a ratchet mechanism including a spring biased plunger and recesses formed on the inner face of said one of said wheels to cooperate with said plunger, said plunger having a cam portion to deflect said plunger inwardly as it is engaged by the portions of said one wheel between said recesses when said one wheel is rotated in said opposite direction.

5. The combination of claim 4 wherein said manually operable means includes means on said plunger for retracting said plunger to a position in which said cam portion is spaced away from said one wheel as it is rotated.

6. A vacuum cleaner comprising an elongated tank having means for attaching a suction hose to one end thereof, support means for said cleaner including a pair of wheels on said tank at the end remote from said one end, said wheels being mounted on a fixed horizontal axis which is positioned at the bottom of said tank with said wheels extending substantially below said tank to engage a substantial portion of a stair tread when said cleaner is in an inclined position on said stairs with said one end up and the other down, ratchet means on said tank engageable with said wheels to permit rotation of said wheels when said tank is moved in a direction toward said one end and to lock said wheels when said tank is moved in the opposite direction, and manually operable means for rendering said ratchet means inoperative.

7. A vacuum cleaner comprising an elongated tank having means for attaching a suction hose to one end thereof, support means for said cleaner including a pair of wheels on said tank at the end remote from said one end, said wheels being mounted on a fixed horizontal axis which is positioned at the bottom of said tank with said wheels extending substantially below said tank to engage a substantial portion of a stair tread when said cleaner is in an inclined position on said stairs with said one end up and the other down, ratched means on said tank engageable with said wheels to permit rotation of said wheels when said tank is moved in a direction toward said one end and to lock said wheels when said tank is moved in the opposite direction, and manually operable means for rendering said ratchet means inoperative, said wheels are each formed with an annular groove in their opposed faces, closely spaced partitions extending across said grooves to divide said grooves into a plurality of adjacent recesses, said ratchet means including spring biased plungers which extend into said recesses.

8. The combination of claim 7 wherein said plungers have cam surfaces on their ends which engage said paritions to bias said plungers out of said recesses on rotation of said wheels in one direction and on rotation on the other direction said plungers engage said partitions to lock said wheels against rotation.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO 3 1 535 DATED May 6, 1975 |NvEN 0 (5 Jean P. DuBois and Roger A. Rieokma'n' It is certified that error appears in the ab0ve-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 14 after The ""house" should be -hose-;

Column 1, line 26 after "rollers" insert --normally--;

Column 1, line 50 after rearward, "mmovement" should be --movement-;

Column 1, line 57 insert --forwardbefore "direction";

Column 6, line 51 before "direction" insert -first-;

Column 8, line 4 "ratched" should be --ratchet-;

Column 8, line 17 "pa" should be -par--;

Column 8, line 18 "ritions" should be --titions--;

Column 8, line 19 "rotation on" should be --rotation in;

Signed and Scaled this ninth Day of December 1975 '[SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN A M-fling Uffivt Commissioner ofPatenIs and Trademarks

Claims

3. The vacuum cleaner of claim 1 wherein said wheel brake is activated by rotation in said direction and said actuation is produced with less than a 30* rotation of said wheels.