US 2513587 A
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Description (OCR text may contain errors)
y 1950 D. H. REEVES 2,513,587
VACUUM CLEANER BRUSH DRIVE Filed Nov. 20, 1944 Fig.1
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MWKM 8W Mm! Patented July 4, 1950 Donald H. Reeves,,Dayton, ilhio, assignor to Genoral Motors Corporation, Dayton, Ohio, a corporation of Delaware Application November 20, 1944, Serial No. 564,306
This invention relates to a domestic appliance and more particularlyto an improved iorm oi vacuum cleaner.
One object of this invention is to provide an automatic means for adjusting the height of the agitator.
Another object oi this invention is to provide a height adjusting mechanism which will automatically compensate for brush wear.
Another object of this invention is to provide an improved agitator drive mechanism which eliminates the need for a belt.
Still another object of this invention is to provide an improved overload release between the agitator and the driving motor.
It is another object of this invention to provide a hydraulic fluid drive between the vacuum cleaner motor and the brush which makes it possible to operate the agitator at the most desirable speed for conserving the brushes and at the same time efilciently cleaning the rug surface.
Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of element It. The elements it are pivoted to the casing In by suitable pivots such as the pivot it so that movement'oi each element It about its pivot it will cause an adjustment in the height of the agitator it relative to the nozzle opening it.
Referring now to Fig. i. of the drawings, reference numeral 2% designates an electric motor which is used for supplying power for operating the main vacuum cleaner fan as through any suitable drive means (not shown). The motor operates a fluid pump as which forms a part of a hydraulic system for driving the agitator it and for adjusting the height or the agitator it relative to the surface to be cleaned. Fluid under pressure is discharged from the pump through the line 26 having one branch 28 leading to the pressure relief valve 39, another branch 32 leading to a height adjusting mechanism generally designated by the reference numeral 34,
. 2 and a third branch 36 leading to a fluid motor 38 located at one end of the agitator l4 and directly connected to the agitator shaft 40 so as to operate the agitator. Reference numeral 42 designates a fluid reservoir oi the type commonly used in hydraulic power systems, and reference numeral 44 designates the fluid return line leading to the inlet of the pump 28.
If for any reason the agitator becomes jammed so as not to allow the motor 38 to operate, an excessive pressure will be built-up at the outlet of the pump 24 with the result that the relief valve 30 will open and allow the fluid to return to the inlet of the pump 24. A spring 50 normally holds the relief valve 30 in its closed position and is of sufficient strength to hold the valve 30 closed at all times except when the agitator becomes jammed.
During normal operation of the motor 20, fluid will be supplied by the pump 28 for operating the agitator H at the desired speed. By virtue of the use of a hydraulic drive from the main motor 20 to the brush l4 it is possible to design the system so as to operate'the brush it at any desired speed. In order to simplify this disclosure, the internal mechanisms .of the pump 26 and the motor 38 have not been shown as hydraulic motors and pumps of this type are now well-known and commonly used in a large number of applications.
The fluid leaving the pump 24 is supplied under pressure to the motor 38 and the pressure within the lines 28, 32, and 36 will be determined largely by the amount or power required to operate the agitator it. Thus, whenever the agitator it is too low so that it brushes the carpet or other surface to be cleaned too vigorously, an excessive amount of power will be required with the result that an excessive amount 01' pressure will build up within the height adjusting mechanism 3 2.
The height adjusting mechanism comprises an outer casing 52 within which there is provided a pressure responsive bellows 5t for operating the plunger 56 which has its inner end secured to the end wall 58 oi the bellows 54 and has its outer end pushing against the projection-6d provided on the arm 62 of the bracket it. A suitable spring 6%, arranged as shown, tends to bias the pin 56. and the agitator bracket it into a position in which the agitator contacts the surface to be cleaned with the maximum desired pressure. The force of the spring Ed is partially overcome by the fluid pressure built-41p within the casing 52 during operation of the pump 26.
The spring Ed is designed to exert just enough force to maintain the agitator Hi at the most eflicient height for proper cleaning.
The agitator M is preferably of the type employing tour spirally arranged brush segments amass? which extend the full length of the agitator. Inasmuch as the construction of the agitator is broadly immaterial, the agitator has been shown somewhat diagrammatically in order to eliminate needless details.
For purposes of illustration, I have shown an arrangement in which the height adjusting means adjusts the height of the agitator without in any way adjusting the height of the nozzle,
whereas, it is within the purview of this invention to utilize a height adjusting means of this type for elevating both the agitator and the floor nozzle within which the agitator is disposed.
The agitator supporting brackets l6 are preferably mounted to move in unison and to be actuated by a single height adjusting mechanism. However, each bracket 16 could be individually operated by a separate height adjusting means both of which would be connected into the hydraulic system in the manner shown.
While the form of embodiment of the invention as herein disclosed constitutes a preferred form,
it is to be understood that other forms might be 1 adopted, as may come within the scope of the claims which follow.
What is claimed is as follows:
1. In a vacuum cleaner, 9. housing having a ing a member movable in response to changes in the pressure in said lines, and means whereby movement of said member causes movement of the means for adjustably supporting the agitator in a direction away from said nozzle opening.
2. In combination with a rotary surface treating element, a biasing arrangement for biasing the surfacing treating element toward the surface to be treated, a hydraulic system including a pump and a hydraulic motor drivingly connected to said rotary element, and means responsive to the pressure in the hydraulic system at the inlet of said hydraulic motor for reducing the pressure between the rotary element and the surface being treated.
3. In a. vacuum cleaner, a housing having a floor nozzle opening, a rotatable agitator member disposed within said/nozzle, a biasing arrangement for biasing the agitator toward the nozzle opening, a motor, a hydraulic system for transmitting power from said motor to said agitator, said system including a pump operated by said motor and a hydraulic motor for rotating said agitator, and means responsive to changes in the pressure at. the inlet of said hydraulic motor for controlling the height of said agitator relative to said nozzle opening.
4. In a vacuum cleaner, a nozzle member having an air inlet opening, an agitator member adjacent said opening, means for adjustably supporting said agitator member relative to the surface to be cleaned, said means including a biasling arrangement for biasing the agitator member toward the surface to be cleaned, fan means for creating a suction at said nozzle opening, a. motor, a hydraulic system for transmitting power from said motor to said agitator member, and
means opposing said biasing arrangement and responsive to an increase in pressure in said system between the motor and the agitator for adjusting said agitator member in a direction away from the surface to be cleaned.
5. In a vacuum cleaner, a nozzle member, a rotatable agitator member adapted to agitate the surface of the material to be cleaned, afan for creating a suction at the nozzle of said nozzle member, an electric motor for operating said fan, power transmitting means whereby said motor imparts rotation to said agitator member, said power transmitting means comprising a hydraulic system including hydraulic pump means and a hydraulic motor, a biasing arrangement for biasing the agitator member out through the nomle of the nozzle member and means responsive to an increase in the pressure in said system for I retracting the agitator member relative to the nozzle of the nozzle member.
6. In a vacuum cleaner, a nozzle member, an electric motor, a fluid pump operated by said motor, an agitator disposed within said nozzle member, means for biasing said agitator toward the surface to be cleaned, a hydraulic motor drivingly connected to said agitator, fluid flow connections between said pump and said hydraulic motor, said pump having an inlet and an outlet, means for by-passing fluid from the outlet of said pump to the inlet of said pump in response to a predetermined pressure at the outlet of said pump, and means responsive to increase in pressure in said connections for opposing the action of said biasing means.
7. In a vacuum cleaner, a housing having a floor nozzle opening, an agitator disposed within said nozzle opening for frictionally engaging the material to be cleaned, adjustable means for'adjusting the location of the agitator within the.
nozzle opening for varying the degree of frictional engagement so as to vary the amount of agitation, said adjustable means including a biasing arrangement for biasing the agitator out of the nozzle opening, a hydraulic pump, a hydraulic motor drivingly connected to said agitator, fluid flow lines between said pump and said motor,
and means responsive to an increase in the pressure within a portion of said lines for retracting said adjustable means to draw the agitator further into the nozzle opening so as to limit the degree of frictional engagement between said agitator and the surface to be cleaned.
DONALD H. REEVES.
REFERENCES CITED The following references are of record in'the file of this patent:
UNITED STATES PA-TENI'S 564,459 Great Britain Sept. 2a, 1944