US2978733A

US2978733A - Vacuum cleaner suction regulator

Info

Publication number: US2978733A
Application number: US708934A
Authority: US
Inventors: Wahlborg Karl John
Original assignee: Electrolux AB
Current assignee: Electrolux AB
Priority date: 1957-01-18
Filing date: 1958-01-14
Publication date: 1961-04-11
Anticipated expiration: 1978-04-11
Also published as: DE1117273B; GB853526A; NL101886C; FR1189789A

Description

K. J. WAHLBORG VACUUM CLEANER SUCTION REGULATOR April 11, 1963 Filed Jan. 14, 1958 VACUUM CLEANER SUCTION REGULATOR Karl John Wahlborg, Stockholm-Vallingby, Sweden, as-

signor to Aktiebolaget Electrolux, Stockholm, Sweden, a corporation of Sweden My invention relates to a suction regulator for varying the suction elfect transmitted to a cleaning appliance in a suction line of a vacuum cleaner.

It is an object of my invention to provide an improved suction regulator of this type which is of simplified construction and effectively regulates the suction effect transmitted to a cleaning appliance in a suction line of a vacuum cleaner.

Another object of the invention is to provide an improved suction regulator which automatically regulates the suction effect transmitted to a cleaning appliance responsive to a condition incident to a cleaning operation effected by the cleaning tool.

A further object of the invention is to provide an improved suction regulator which automatically regulates the suction effect transmitted to a cleaning appliance responsive to the forces produced and developed with movement imparted to the cleaning appliance by an operator. I accomplish this by providing in a suction line of a vacuum cleaner a pair of telescopically fitted hollow members in which one member is provided with a slot which is covered or uncovered by the other member to vary the size of a leakage port and determine the suction effect reaching the cleaning appliance. In the preferred embodiment the hollow members are biased to move apart with the aid of a resilient element to increase the size of the leakage port, and arranged to move toward o e another against the compression of the resilient element to reduce the size of the leakage port. When the cleaning appliance is being moved back and forth over a rug or other surface being cleaned, the size of the leakage port is automatically regulated so that favorable operating conditions will always prevail during a cleaning operation.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the following description taken in connection with the accompanying drawing, in which:

Fig. 1 is a perspective view of a suction cleaner having a cleaning appliance connected to a suction line provided with a suction regulator embodying my invention;

Fig. 2 isan enlarged fragmentary perspective view, partly broken away and in section, of the suction line shown in Fig. 1 to illustrate the suction control more clearly; and

Fig. 3 is an exploded perspective view of the suction regulator shown in Fig. 2 to illustrate details.

Referring to the drawing, I have shown my invention in connection with a horizontal tank-type suction cleaner which includes a casing having an end cover 10a. The end cover 10a is provided with an inlet 10b to which a suction hose 11 is adapted to be removably secured in any suitable manner (not shown). Suitable cleaning appliances, such as a nozzle 14 havinga suction inlet 14a,

2,978,733 Patented Apr. 11, 1961 for example, may be connected to, a wand which in turn is connected to the outer free end of the hose 11 and through which air is drawn into the casing 10 by a suitable motor-fan unit (not shown) disposed therein. Dust and dirt entrained in the air during a cleaning operation are separated from the air when the latter passes through a dust collecting member (not shown) disposed in the casing, and air from which dust and dirt have been removed is discharged from the casing 10 at the end thereof opposite the end cover 10a.

The wand, which is normally at an acute angle to the vertical when employed to manipulate the nozzle 14 over a horizontal surface to be cleaned, comprises outer and inner

tubular members

12 and 13, the outer tubular member 12 having an enlarged end section or socket 16 within which the inner tubular member 13 telescopically fits. The socket 16 is formed with an opening 17 whose eifective size is changed responsive to axial movement of the outer and inner

tubular members

12 and 13 with respect to one another, thereby regulating the suction eflt'ect transmitted through the suction line from the casing 10 to the cleaning appliance 14,

In accordance with my invention, the telescopically fitting end sections of the outer and inner

tubular members

12 and 13 form part of a suction regulator 15 which also includes a hollow sleeve-like element 18 in the form of a split ring which is slit at 19 and externally threaded and provided with spaced apart lugs or bosses 20 at its inner surface. The element 18, which is resilient in character, is mounted in position on the inner tube 13 by expanding the element sufficiently to enable it to be moved over such tube to a region at the immediate vicinity of slots or openings 21. In its mounted position on the inner tubular member 13, the openings 21 receive the lugs 20 of the element 18 and the latter assumes its undistorted shape seen in Fig. 3, the element 18 in such mounted position being in the position illustrated in Fig. 2.

The element 18 forms an externally threaded portion of the inner tube 13, and, due to the inherent resilient character of the element, the lugs or bosses 20 are effectively held in the slots 21 so that the element 18 forms a unitary part of the inner tube 13 and is always movable therewith.

The externally threaded element 18 is adapted to receive an internally threaded hollow sleeve 22 provided with an inwardly extending flange 23 which defines an opening 23a within which the socket 16 of the tubular member 12 is axially movable; Within the space 26a of annular form, between the inner tubular member 13 and hollow sleeve 22, is disposed a helical spring 26 having one end thereof bearing against the element 18 and the other end thereof bearing against anannular washer 24. The outer tubular member 12 is provided with an outwardly extending flange 25 which, in the position illustrated in Fig. 2, is disposed between the annular washer 24 and flange 23.-

The socket 16 of the outer tube 12 is formed with an axially extending elongated slit 27 through which extends a set screw 28 that threadedly engages a hollow bushing 30 fixed to the inner tubular member 13 at an opening 30a therein. With this arrangement, the outer and inner

tubular members

12 and 13 cannot be rotated with respect to one another and are only axially movable toward and from one another. If desired, the

tubular members

12 and 13 may be locked together by the set screw 28, a washer 29 being provided on thelatter to hold the members in any desired position with respect to one another.

Assuming that the set screw 28 is turned to permit the inner and outer

tubular members

12 and 13 to move axially with respectto one another, it will be understood that the helical spring 26, which'is'under compression and is disposed between the element 18 and the outwardly extending shoulder 25 of the outer tubular member 12, acts to move the

members

12 and 13 apart as far as possible until theshoulder 25 engages the inwardly extending flange 23 of the hollow sleeve 22. Since the hollow sleeve 22 is in threaded engagement with the element 18, the hollow sleeve 22 and element18 form unitary parts of the inner tubular member 13. By shifting the hollow sleeve 22 axially on the threaded element 18, the extreme right-hand end 13a of the inner tubular member 13 can be moved nearer or farther from the flange 23 to determine the extent to which the slot 17 is uncovered by the inner tubular member 13 when the

tubular members

12 and 13 are separated as far as possible, as seen in Fig. 2.

The

tubular members

12 and 13 can be moved toward one another against the compression of the spring 26 until the extreme end 13a of the inner tubular member 13 engages the shoulder 31 of the outer tubular member 12. Under these conditions, the

members

12 and 13 are as close together as possible and the slot 17 in the outer tubular member 12 is completely closed by the end of the inner tubular member 13.

When the wand formed by the telescopically

fitting tubes

12 and 13 is being'moved backward and forward to move the nozzle 14 or other cleaning appliance back and forth over a horizontal surface to be cleaned, the suction regulator 15 just described functions automatically to vary the extent to which the slot 17 is covered by the inner tube 13 and thereby regulate the suction effect transmitted through the suction line from the cleaner casing 10 to the nozzle 14 whose suction inlet 14a remains the same in size during the forward and backward movements of the nozzle.

When the suction cleaner is being operated and the inclined wand formed by the telescopically

fitting tubes

12 and 13 is being moved forward over a surface being cleaned, for example, there is a natural tendency for an operator to press the upper tubular member 12 of the inclined wand downwardly and force the nozzle against the surface during its forward movement over the surface. Under these conditions, downward movement is imparted to the socket 16 of the upper tubular member 12 with respect to the lower tubular member 13. An upwardly directed reaction force is also developed in the lower tubular member 13 due to friction produced between the nozzle 14 and the surface being cleaned. As the result of the upward and downward forces produced when the wand is being moved forward on the surface being cleaned, the outer and

inner tubes

12 and 13 are moved toward one another against the compression of the spring 26 and the slot 17 will be closed by the upper end of the inner tube 13. Hence, downward movement is imparted to the upper tubular member 12 with respect to the lower tubular member 13 to close the opening 17, such movement being responsive to the downwardly directed force applied by an operator at an acute angle to the vertical, along the axis of the inclined wand, during the forward movement of the suction nozzle 14 over the surface with its suction inlet 14a in good physical contact therewith.

When the inclined wand is subsequently moved backward while the upper tubular member 12 is being held by the operator, a predominately downward force is no longer applied to the inclined wand along its axis and such downward force may be replaced by a lifting force. Also, the nozzle 14 while being moved backward with its suction inlet 14a in physical contact withthe surface may exert a dragging efiFect on surface tending to resist movement thereof. Under these conditions, the forces produced longitudinally of the wand act to separate the outer and

inner tubes

12 and 13 thereof, with separation of the tubes being promoted by the biasing action of the spring 26 which is under compression. When the outer and inner tubes 12 :and ;13.move apart in this manner,-

the extent to which the slot 17 is covered or closed by the inner tube 13 is reduced. Hence, longitudinal movement is imparted to the upper tubular member 12 to increase the size of the opening 17 responsive to the horizontal component of the force applied by an operator to the inclined wand during the rearward stroke of the suction nozzle 14 over the surface with its suction inlet 14a in good physical contact therewith. Irrespective of the size of the opening or slot 17 and even when the opening is fully closed, suction effect will always be transmitted through the wand to the nozzle 14.

In view of the foregoing, it will now be understood that the suction regulator 15 functions automatically responsive to a condition incident to the cleaning operation being performed to regulate the manner in which suction eflect is transmitted through the suction line from the cleaner casing 10 to the nozzle 14. When the nozzle 14 is being moved forward with its suction inlet 14a in good physical contact with the surface being cleaned, the slot 17 is closed by the upper end of the inner tube 13 in the manner described above. Under such an operating condition, when the floor covering or rug is perfectly smooth and stretched out due to the operator standing on a part thereof, it is of distinct advantage to transmit maximum suction through the suction line to the cleaning nozzle 14 when the latter is being pressed against the surface being cleaned.

When the nozzle 14 is subsequently being moved backward with its suction inlet 14a in good physical contact with the surface, the slot 17 is no longer covered by the inner tube 13 so that a part of the suction effect produced in the suction line is lost. Due to leakage of suction at the uncovered slot 17, less suction effect is transmitted to the nozzle 14 whose suction inlet 14a is still in good physical contact with the surface being cleaned, thereby reducing the tendency of the rug or other floor covering to be drawn to the nozzle. When the suction effect transmitted to the suction inlet 14a of the nozzle 14 is reduced sufiiciently during backward movement of the inclined wand, a light scatter rug will remain smoothly on a floor even when the cleaning nozzle is moved toward the center of the rug from a region beyond an outer edge thereof.

Since the hollow sleeve 22 is axially movable on the inner tube 13, the end 13a of the tube may be adjusted with respect to the slot 17 to determine the maximum size opening produced in the tube 13 when the

tubes

12 and 13 are moved apart as far as possible and the slot 17 is uncovered. If desired, the set screw 28 may be employed to lock the outer and

inner tubes

12 and 13 so that the slot 17 will remain completely closed and render the suction regulator 15 ineffective. Also, the set screw 28 may be employed to lock the

tubes

12 and 13 in such a manner that the slot 17 will be in a partially open position and remain in such fixed open position during both forward and backward strokes of the wand and nozzle 14 attached thereto.

Although I do not wish to be limited thereto, the element 18 and hollow sleeve 22 desirably may be formed of a suitable plastic like nylon, for example. A plastic of a type like nylon has a relatively small coefiicient of friction and possesses an inherent lubricating quality which makes it possible to shift the hollow sleeve 22 axially of the threaded element 18 without any difficulty.

Although I have shown and described a single embodiment of my improved suction regulator, I do not desire my invention to be limited to the particular arrangement set forth, and I intend in the succeeding claims to cover all modifications which do not depart from the spirit and scope of my invention.

What I claim is:

1. A vacuum cleaner having a suction line including a nozzle having a suction inlet and an elongated hollow wand, means connecting thenozzle'and the wand, said connecting means being'so constructed and arranged that when the nozzle is in its normal operating position on a horizontal surface to be cleaned with its suction inlet in physical contact therewith, the wand is at an acute angle to the vertical, means comprising the wand for manually moving the nozzle forward and rearward on the surface with its suction inlet in physical contact with the surface during such movement, the elfective size of the suction inlet of the nozzle being the same during the forward and rearward movements thereof, the wall of the wand having an opening, structure embodied in the wand for decreasing the size of the opening during forward movements of the nozzle responsive to force applied downwardly on the inclined wand along its axis when manually moving the nozzle forward with its suction inlet in physical contact with the surface, and said structure including means for increasing the size of the opening in the wand during rearward movement of the nozzle responsive to a pulling force having a horizontal component applied to the inclined wand when manually moving the nozzle rearward with its suction inlet in physical contact with the surface, said structure being so constructed and arranged that, irrespective of the size of the opening in the wand and even when the opening is fully closed, suction efiect will always be transmitted through the wand to the nozzle.

2. Apparatus as set forth in claim 1 in which the elongated wand comprises a pair of telescopically fitting tubes formed to provide the opening in the wand which varies in size with relative axial movement of the tubes, the

means for increasing the size of the opening including resilient means for biasing the tubes apart, and means for limiting the extent the tubes can be moved apart.

3. Apparatus as set forth in claim 2 including means for adjusting the compression of the resilient means.

4. Apparatus as set forth in claim 1 in which the elongated wand comprises a pair of telescopically fitting tubes, one of the tubes having the opening and the other tube being movable past the opening, the means for increasing the size of the opening including resilient means for biasing the tubes apart, and means for limiting the extent the tubes can be moved apart.

5. Apparatus as set forth in claim 4 including means for locking the tubes together in any one of several positions between closed and fully open positions of the opening.

References Cited in the file of this patent UNITED STATES PATENTS Germany Oct. 31, 1928