US 2715452 A
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Description (OCR text may contain errors)
Aug. 16, 1955 M. A. KENT 2,715,452
SUCTION CLEANER Filed Dec. 6, 1950 v ATTORNEY Unite This invention relates to new and useful improvements in suction cleaners and is applicable both to cleaners for household or domestic use and to commercial types of suction cleaners such as are used in cleaning operations in hotels, apartment houses, office buildings and the like.
An object of the invention is to provide in an electric motor operated suction cleaner wherein the air drawn into the cleaner during use is also employed for cooling of the electric motor or motors, a means whereby on clogging of the machine in such manner that air is not being dra-wn into the same in suicient quantity for proper functioning at a predetermined level of efficiency, the cir cuit to the electric power plant is automatically opened.
Other objects and advantages of the invention will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawing wherein a satisfactory embodiment of the invention is shown. However, it is to be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention and the scope of the appended claim.
In the drawing:
Fig. l is a side elevational view of the upper portion of the cleaner;
Fig. 2 is a similar" view, on a larger scale, showing one of the motor units with a thermostatic switch mounted thereon;
Fig. 3 is a rear elevational view of said thermostatic switch;
Fig; 4 is a schematicl view showing the wiring diagram; fl'
Fig. 5 shows a modified wiring arrangement.
Referring in detail to the drawing, and at first more particularly to Figs. l-4, in Fig. l is shown the upper portion of the cleaner fully disclosed in co^pending application of Kent and Yutzler, Serial number 172,758, filed July 8, 1950, and since the parts are the same as those in said application, the same reference numbers have been employed.
Thus, the cleaner generally designated may include a wheeled platform construction (not shown) and` a pair of upright arms of which but'the arm 21 is shown. Supported by and located between the upper end portions of said arms or uprights is a housing including an annular shell 23 open through its top and bottom ends. To ward their upper ends the uprights are offset inwardly or toward one another as at 28 whereby their upper end portions are against the outer sides of the shell 23 and such portions are rigidly and permanently secured to said shell as through rivets 29.
A cover 70 of metal or any other desired material encloses one or more units 59, as for example, three, andincludes at its lower end an outwardly directed annular ange 71 carrying a depending flange 72 having its lower edge portion rolled or formedl into a bead 73. The upper end portion of cover 70 is substantially closed by a wall '74 having a central opening 75 therethrough. Units 59 States Patent() 2,7%,452 Patented Aug. 1S, 1955 ICC each include an electric motor and a blower or fan driven by said electric motor.
When the cover 70 is in position on the machine, its depending ange 72 is about the upper edge portion of the shell 23. Thus, shell 23 and cover 70 together constitute a housing mounting various parts, all as disclosed in the above mentioned application. A lining 77 of sound deadening or absorbing material as, for example, felt, is secured to the inner surface of the cover 70 and such lining is coextensive with said inner surface and has an opening 78 therethrough registering with the opening above mentioned as in the upper wall 74 of the cover.
With all the parts in their proper assembled relation in the shell 23, the cover 70 and parts mounted thereon are secured in position by draw pull catches 81, the detailed description of which is not here given. In the use of the present machine, air drawn from the shell 23 by the suction units 59 is exhausted through the aligned holes 75 and 78 above described. A muffler structure is mounted' on the upper wall of the cover 70, the air being discharged passes through such muffler. This muffler structure comprises an assembly generally designated 79' and described in detail in the above identified application.
.ln the use of the machine, a hose (not shown) having at one end a suitable tool has its other end connected with an intake nipple 97 communicating with the interior of the casing 23. As the machine is used, dust or dirt laden air is drawn in through the nipple 97, the dust or dirt separated from the air, and the latter passed upwardly about the units 59 and out through the registering openings 75 and '7S to the n'iuifier. This air serves to maintain the units 59 at operating temperature and against overheating.
A U-shaped handle 1MB has the end portions of its side arms suitably secured to the machine as by having them riveted at 111 to the upper portions of the upstanding members or arms 2i. This handle is for use when moving the machine about.
While the foregoing description relates to the particular machine disclosed in the above entitled application, this is a matter of convenience for disclosure purposes. Such machine is herein referred to merely for the purpose of showing one application of the invention and it is to be understood that the invention is applicable to other constructions of both commercial and domestic types of machines. The construction of the machine referred to is herein considered as a type of suction cleaner wherein air is drawn into the machine and therein separated from foreign matter such as dust, dirt, water, etc., and then the air is used to maintain the power units of the machine at operating temperature by cooling such units and preventing their overheating.
Additionally, it will be understood that in the type of machine referred to it is not necessary that the machine be equipped with three units 59 as disclosed herein, since more or less units may be employed, the essential question being that the power means is electric and is located within a closed chamber and is cooled by air drawn into the machine during use of the latter, which air is separated from the dirt or dust, water or other material being collected and then used to prevent overheating of the electric power unit.
According to the present invention, the machine of the type disclosed is equipped with means whereby on the closing of a switch means the power unit of the machine is energized and the machine placed in operation. This is also conventional in the type of machine referred to. However, in the present instance, the machine is further equipped with means whereby should its intake or some other part become clogged so that the machine is not operating at a predetermined level of efliciency and air in the proper volume to efficiently take up dirt or dust or water is not being drawn into the machine, the power circuit will be automatically opened.
This automatic opening of the power circuit is brought about by a thermostatic switch located within the closure with the power unit, which unit will, of course, become overheated on the failure to move large volumes of air over it. The switch means of the present machine includes means to be manually held closed and establish the circuit to the power unit through by-passing of said thermostatic switch to have the machine operate. This manual operation of the switch means is to take place after the clogging has been removed and it is then only necessary to manually hold the switch means in its bypassing position for a short time since during such time large volumes of air will be taken into the machine and passed over the power units and the thermostatic switch to cool the same. On suiiicient cooling, the second mentioned switch means is released and moves to open circuit position and the second mentioned switch means is already closed or is then closed to again energize the power unit or units, and the machine is used as formerly.
Referring to Fig, 4, the cover 70 is there shown as enclosing three of the units 59. In such figure, the power intake wires are shown at 112 and 113 connected respectively with terminals 114 and 115 of a switch means generally designated 116. From a switch contact 117, a wire 11S leads to a terminal 119 of a thermostatic or monitor switch generally designated 120. Contact 117 is one of a pair including a contact 121 and the latter is permanently connected with contact 122 of a pair also including contact 123 by means of a wire 124. A wire 125 from contact 123 connects with a terminal 126 of thermostatic switch 120 and a second wire 127, in eiect a continuation of wire 125, through leads 121i, 129 and 131) is connected with the three units 59. Then from such units, leads or wires 131, 132 and 133 are secured in a wire connector 134 from which a lead 135, electrically connected with all of the wires 131, 132 and 133, extends and is at its free end electrically connected with switch contact 122.
With the blade 136 of switch 116 in the position of Fig. 4, a circuit is completed through the units 59 and they are operating. Such circuit is through the lead 112 to contact 115i to contact 117 through wire 118 to terminal 119 of the thermostatic switch 121i. Such terminal will be at this time electrically connected with terminal 126 and from the wire 127 and its branches the circuit is completed through the units 59 back through the wires 131, 132 and 133 to the wire 135, thence to switch terminal 122 and through Wire 124 to switch terminal 121 through a blade of the switch 136 to switch terminal 115 and to the return lead 113.
Should there be a failure of sumcient volume of air moving around and through the units 59, they will become overheated and cause excessive heating within the cover 7i) whereby the thermostatic switch 12@ will function opening the circuit between its terminal 119 and its terminal 126. The mentioned failure of movement of sufficient volume of air occurs when the machine is in some way clogged and is operating below a predetermined level of etiiciency as determined by the setting or opening point of the switch 120. The motor or motors may be operating at full speed and the sound of the machine be substantially as usual but the machine will not be accomplishing its intended purpose.
Under such circumstances, with the machine cut oit, the attendant cannot proceed to go over a iioor or carpet tiinking he or she is really cleaning. Generally, there will be a clogging of the tool or some place between the tool and the machine and this obstruction must be removed. Then the operator throws the switch means 136 to have its blades engage the contact 122 and 123. This closes a circuit to the units 59, in effect, by-passing the thermostatic switch 120.
Such circuit is from lead 122 to contact 114 through Zit the switch blade to contact 123 which through terminal 126 is connected with wire 127 and then through the branches 128, 129 and 130 of the latter to the respective units. The return from the units is through the branches 131, 132 and 133 to the lead 135, contact 122, the witch blade, to contact 115 and thence through the return wire 113. When the switch blade is in the last mentioned position it must be held there to maintain electrical engagement with the contacts 122 and 123 since a spring or other means 137 is constantly urging switch blades away from the contacts 122 and 123.
However, the operator need only hold the switch means in this closed position for a short time since after all clogging has been removed, large volumes of air are being drawn into the machine, separated from the dirt c-r dust or water it is carrying into the machine, and then passed upwardly through the cover 70 to be exhausted. However, in moving through the cover 70, this air moves about and through the units 59 very rapidly cooling them and exhausting heat from within the cover so that the thermostatic switch 120 returns to its normal condition closing a circuit between its terminals 119 and 126. Then the operator flips the switch handle in the opposite direction, as to the position of Fig. 4, and the machine operates in the normal manner.
The thermoplastic or monitor switch 120 has an L- shaped bracket 138 clamped along one of its edges as through the use of bolts 139 passing through pcrforations 149 of the switch housing. By means of a screw 141 this bracket is secured to the housing 142 of unit 59 whereby the entire device is sensitive to temperature changes.
Bracket 138 is located at an edge of the rear side of the switch 120 and in such side the switch housing is open exposing the bimetal member 143. With this construction and location of the switch 120 it is seen that its bimetal part is directly exposed to heat generated within the unit 59 and is located closely adjacent to the unit. Thus, the thermostatic switch is positioned t0 be directly affected by heating up of the unit 59, which heating up would occur with particular rapidity on any clogging of the intake of the machine, such as would prevent the flow of a large volume of air through the cover 70 and about the unit.
Additionally, after the clogging has been corrected the machine is started up by the manual maintenance of the switch in hold position, against the tendency of the spring 137, the thermostatic switch being mounted on one of the units if one or more units is employed, or on the unit if only one unit is employed, will be cooled simultaneously with the cooling of the unit by the large volume of air passed through and about the unit so that the switch will rather quickly automatically close whereupon the manual of the manually operable switch is thrown to on or running position as suggested in Fig. 4. In this way, cooling of the unit or units and closing of switch 121i is rapid. The parts may be cooled to operating temperature in a matter of 15 or 20 seconds as against a wait of 4 or 5 minutes for the parts to cool of their own accord.
Fig. 5 illustrates the invention wherein the switch means is in two separate parts and this arrangement may be preferable in a cleaner of the type described but constructed especially for domestic use. In such ligure, the
same reference characters have been used when applying the parts shown in Figs. 1 4. Thus, there is shown a unit 59, a cover 70 and power lines 112 and 113.
From power line 112 there is a lead 144 to a switch means 14S shown in open relation to a contact 146 in a line 147 to unit 59. Then a lead 143 connects motor or unit 59 with the return power line 113. In such wire 148 is connected the thermostatic switch 120 to function as described in connection with Figs. 1-4. When switch 121) has opened and the machine cleaned of any clogging. switch 120 may be immediately by-passed by closing of a normally open switch means 149 shown as of the pushbutton type. Switch means 149 may be located as desired for hand or foot operation but is normally open as is the second part of the switch means 136.
' Thus, in Fig. 5, the switch means 136 of Figs. l-4 is separated into two parts. The part 149 is a normally open switch. Thus, it may close the circuit in by-passing relation to the thermostatic switch 120 only while it is held closed. Switch means 149 may be a time switch to open after the passage of a predetermined time interval, as or 20 seconds. Where it is not a time switch but a straight manually closed normally open switch, as shown, the operator will preferably hold it closed until he counts up to 15 or 20.
From the foregoing it will be seen that in any embodiment of the invention the power circuit of the cleaner is automatically opened if a careless operator allows the dust lter (not shown) to become clogged, or the hose or cleaning tool to become clogged, or the cleaner to continue to operate after the water shut-off has indicated that the water receptacle is full and should be emptied. The opening of the thermostatic switch 120 depends on its setting. It is set to open when the volume of air passing over the units 59 is in such small Volume as to indicate that the machine is being operated below a predetermined efficiency at insuicient suction pressure. Should the shut-olf switch 120 open the circuit to the power unit or units, the operator must first locate the cause (plugging, clogging, etc.) and remove it so the air may again move freely in good volume through the cleaner. Thereafter, he may proceed as outlined above.
Having thus set forth the nature of my invention, what I claim is:
In a suction cleaner of the type wherein air is drawn into the cleaner with dust or Water or other matter being taken up by the cleaner and is separated from such matter, a housing including a motor housing part having an air outlet opening and a material receiving part in air communication with said motor housing part and having an air inlet opening, an electric motor suction fan unit in said motor housing part interposed in the path of the air drawn thereby through said housing and whereby the temperature of said unit and of the air within said motor housing part is affected by the volume and velocity of said air drawn therethrough, a circuit including said motor unit, and a normally closed thermostatic switch in said motor housing part so positioned as to be exposed to and operated by temperature changes in said motor housing and connected in said circuit for opening the latter on the temperature within said motor housing part, aifected by the temperature of said motor unit, reaching a predetermined point, a normal operation switch means in said circuit and including manual means for opening and closing said circuit through said thermostatic switch, said normal operation switch means adapted when closed to remain in closed position until opened through manual operation of said manual means, a by-pass circuit including said motor unit and by-passing said thermostatic switch, and an auxiliary bypass switch means in said bypass circuit manually operable to close said by-pass circuit and including biasing means adapted to normally open said by-pass circuit, whereby upon manual release of said by-pass switch means after closing said by-pass switch means automatically opens said by-pass circuit.
References Cited in the ile of this patent UNITED STATES PATENTS 2,027,071 Toy Jan. 7, 1936 2,035,628 Whitmer et al Mar. 3l, 1936 2,045,496 Skinner .Tune 23, 1936 2,272,459 Eaton Feb. 10, 1942 2,296,063 Shaw Sept. 15, 1942 2,564,468 Anderson Aug. 14, 1951 2,580,644 Lofgren Jan. l, 1952 2,625,239 Senne Jan. 13, 1953 FOREIGN PATENTS 652,053 Germany Oct. 23, 1937