US3464859A

US3464859A - Method and apparatus for vacuum cleaning

Info

Publication number: US3464859A
Authority: US
Inventors: James C Hamrick
Original assignee: J L Products Inc
Current assignee: J L Products Inc; Benjamin Electric Manufacturing Co
Priority date: 1966-08-19
Filing date: 1966-08-19
Publication date: 1969-09-02
Anticipated expiration: 1986-09-02
Also published as: US3464858A; US3520725A; US3468334A

Description

J. C. HAMRICK METHOD AND APPARATUS FOR VACUUM CLEANING Sept. 2, 1969 5 Sheets-Sheet 1 Filed Aug. 19, 1966 INVENTOR I JAMEs C. HAMEtQK BYwm L 4-4 ATTORNEY-S l-" 2, 1969 J. c. HAMRICK 3,464,859

METHOD AND APPARATUS FOR VACUUM CLEANING Filed Aug. 19, 1966 5 Sheets-Sheet 2 1;: 9- INVENTOR? JAMEs C. HAMRICK BYMMJI%K, 22049-7401 ATTORNEY 5 Sept. 2, 1969 J. c. HAMRICK METHOD AND APPARATUS FOR VACUUM CLEANING 5 Sheets-Sheet :5

Filed Aug. 19, 1966 p 1969 J. c. HAMRICK 3,464,859

METHOD AND APPARATUS FOR VACUUM CLEANING Filed Aug. 19, 1966 5 Sheets-Sheet 4 Sept. 1969 J. c. HAMRICK 5 METHOD AND APPARATUS FOR VACUUM CLEANING Filed Aug. 19, 1966 5 Sheets-Sheet 5 Ill-" 3,"

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ATTORNEYS INVENTOR I United States Patent 3,464,859 METHOD AND APPARATUS FOR VACUUM CLEANING James C. Hamrick, Matthews, N.C., assignor, by mesne assignments, to J L Products Incorporated, Matthews, N.C., a corporation of North Carolina Continuation-impart of application Ser. No. 458,178, May 24, 1965. This application Aug. 19, 1966, Ser. No. 573,707

Int. Cl. B08b /04 US. Cl. 134-21 18 Claims ABSTRACT OF THE DISCLOSURE A vacuum cleaning system having a cleaning hose which is retractably stored within a conduit communicating with a suction blower and wherein the suction blower is utilized to extend the hose outwardly of the conduit by creating a pressure in the conduit above atmospheric pressure. Also, the suction blower serves for withdrawing the cleaning hose into the conduit into retractably stored position.

This application is a continuation-in-part of my copending application for Suction Cleaning System and Method, Ser. No. 458,178, filed May 24, 1965, now Patent No. 3,353,996 and relates to a new and improved method and apparatus for storing, extending and retracting suction cleaning tubes or hoses with respect to conduit-s of a centralized suction or vacuum cleaning system.

The suction cleaning system of said co-pending application includes method and apparatus in which a suction hose of desired length, usually about thirty feet long, is normally stored in a stationary pneumatic conduit and which may be partially or substantially fully withdrawn from the conduit, and wherein the hose may :be so controlled as to partially or fully retract the same within the conduit by controlling at the hose the effectiveness of existing suction force in the conduit acting on the hose.

According to embodiments disclosed in said copending application, a desired length of the hose is manually withdrawn from the stationary conduit. Such manual withdrawal of the suction hose is not objectionable in various centralized suction cleaning systems, especially if a'suction force is not induced in the conduit until after the desired length of the suction hose has been withdrawn. It can be appreciated, however, that the operation of the suction cleaning system can be improved if the extending of the suction hose is effected or aided by other than manually exerting an outward pulling force thereon.

Acordingly, it is the primary object of this invention to provide an improved method and apparatus for cleaning, utilizing a conduit and a flexible cleaning hose movable longitudinally within the conduit and wherein outward movement or extension of the hose from the outlet end of the conduit is effected by creating a positive pneumatic pressure substantially above atmospheric pressure in the conduit for blowing at least a portion of the hose out of the conduit, terminating the pneumatic pressure, and then conducting a suction current through the medium of the hose to an area to be cleaned.

Another object is to provide a method and apparatus of the type described in which the pneumatic pressure is created by directing a blowing air stream into the conduit and restricting its fiow through the hose to extend at least a portion thereof, and wherein the suction current is produced by reversing the direction of flow of the air stream.

Still another object is to provide a method and apparatus of the type described wherein partial or substan- 3,464,859 Patented Sept. 2, 1969 tially complete retraction of the suction hose into the conduit is eliected by sufiiciently restricting flow of the suction current into the hose and the conduit so that the hose is sucked into the conduit under impetus of a reduced pneumatic pressure in the conduit below atmospheric pressure.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which FIGURE 1 is a schematic perspective view of a centralized pneumatic cleaning system embodying the present invention as it may be installed in a building;

FIGURE 2 is a plan view of the central pneumatic unit of FIGURE 1 with the top wall or cover removed and showing a preferred arrangement of the air circulating means and associated components;

FIGURE 3 is a fragmentary vertical sectional view taken substantially along line 3-3 of FIGURE 2;

FIGURE 4 is a front view of one of the outlet boxes looking at the right-hand side of FIGURE 5;

FIGURES 5 and 5A are, collectively, a vertical sectional view of an outlet box for one of the conduits of the system, shown mounted in a wall of the building, and including a flexible pneumatic cleaning or suction hose therein;

FIGURE 6 is a partially exploded perspective view of a preferred form of bleeder valve used in the conduits of the cleaning system;

FIGURE 7 is a rear view of the outlet box of FIG- URE 4;

FIGURE 8 is a sectional plan view of the outlet box taken along line 88 of FIGURE 4;

FIGURE 9 is a longitudinal sectional view through the hand valve unit, showing the same in closed position connected to the outer end of one of the flexible suction hoses;

FIGURE 10 is a transverse sectional view taken along line 1010 of FIGURE 9;

FIGURE 11 is a sectional view similar to FIGURE 9, but showing the valve in open position;

FIGURE 12 is a view similar to FIGURE 11 showing a blowing adapter member positioned in the hand valve and arranged to hold the clapper or check valve member in open position during use of the same for :blowing cleaning;

FIGURE 12A is a transverse sectional view taken along line 12A-12A of FIGURE 12;

FIGURE 13 is a vertical sectional view of the central control valve of the system taken along line 13-13 of FIGURE 2, showing the valve clapper elements in blow-out position;

FIGURE 14 is a view similar to FIGURE 13, showing the valve clapper elements in an alternate or suction position;

FIGURE 15 is a schematic view of the control means associated with the central control valve of FIGURES l3 and 14, including a portion of the electrical circuit associated therewith;

FIGURE 16 is a schematic diagram of the electrical control circuit of the pneumatic cleaning system, and

FIGURES 17 and 18 are side elevations of an electromagnetic latching relay of the electrical system and showing the contacts thereof in two different positions.

Referring more specifically to the drawings, FIGURE 1 shows a typical pneumatic cleaning installation of the present invention wherein a plurality of stationary collection conduits 21, 22, 23 communicate by a common collection conduit 24 with a central pneumatically-operated dirt collection chamber housed in an enclosure A. Collection conduits 21, 22, 23 may extend generally beneath the floor or in the ceiling of a building, as desired, and have respective outlet boxes or

stations

25, 26 and 27 suitably positioned in the floor or wall of the building to provide openings therein for the reception and storage of flexible pneumatic cleaning or vacuum hoses, two of which are shown at 28, 29. For purposes of illustration, it may be assumed that the horizontal runs of conduits 21, 22 extend beneath the floor and above the ceiling, respectively, with the

outlet boxes

25, 26, 27 mounted in openings in the vertical walls of a building. A plurality of bleeder or check valves 31 may be positioned intermediate the lengths of

conduits

21, 22, 24 for purposes to be later described.

Although a separate flexible vacuum hose may be used in outlet box 27 and its conduit 23, this outlet box is shown without a vacuum hose by way of illustrating that either hose 28 or 29 may be alternatively connected to outlet box 27, if desired. It may be desired to use a lesser number of hoses than there are outlet boxes for purposes of economy, or construction conditions may dictate that conduit 23, for example, may be too short to completely receive a vacuum hose of the desired length therein.

In operation of the system according to my said copending application, a portion of either suction hose 28, 29 is withdrawn manually from the corresponding outlet box, a suitable cleaning implement is attached thereto, and the system is energized to produce suction currents in the hose and conduits to collect dirt and waste materials. When an area adjacent the outlet has been cleaned, the hose is retracted back into the corresponding outlet box and conduit by suction for storage until subsequent use thereof.

By incorporating into the system the novel features of the present invention, the flexible vacuum hoses can be easily extended, as well as retracted, by pneumatic pressure created by the air impeller means of the system. By providing a control valve to selectively direct the flow of air inwardly or outwardly along the collection conduits of the system, while simultaneously restricting the flow of air through the hose, negative and positive pressures can be created alternatively in the collection conduits, which pressures act upon the hose to propel it in and out of the conduit.

As seen in the drawings, an upper section of enclosure A (FIGURE 2) houses an air impeller or fan 32 driven by an electric motor M and connected to a central control valve generally indicated at 33. Valve 33 constitutes means for selectively directing pneumatic currents produced by impeller 32 throughout the various conduits of the system, as will be explained. Located below motor M and control valve 33 is a dust or dirt collection chamber 34 (FIGURE 3) partially defined by a horizontal partition 34a upon which motor M, fan 32 and valve 33 may be mounted. Chamber 34 contains a pervious filter bag 35 for the removal of dirt from air currents passing through the system. Filter bag 35 is connected to and communicates directly with an inlet conduit 36 which may penetrate partition 34a and is connected to a housing 37 of control valve 33. The inlet or suction side 32a of fan 32 communicates with chamber 34 through partition 34a to establish an air flow therethrough from the conduits 2124 of the system.

The outlet or discharge side 32b (FIGURES 2 and 3) of fan 32 is connected, as by a flexible conduit 38, to valve housing 37. Valve housing 37 also has common conduit 24 and an exhaust conduit 39 connected thereto. The outer end of conduit 39 is open to the atmosphere. An electrical control device, generally indicated at 41 (FIGURES 2, and 16), is operatively associated with control valve 33 to interconnect the various conduits of the system in a manner to be later described.

Each

outlet box

25, 26, 27 may be of substantially the same construction and only outlet box will be described in detail. However, since conduit 22 extends downwardly from its horizontal run, it will be noted that outlet box 26 is inverted as compared to

outlet boxes

25, 27. As best shown in FIGURES 4, 5, 7 and 8, outlet box 25 may include an outer frame 51 (FIGURE 5) which is preferably generally rectangular in shape and has side flanges 52 (FIGURES 7 and 8) which cooperate with an angle bracket 53 (FIGURE 8) to secure box 25 to a stud 53a or other suitable building frame member adjacent an opening in an outer panel 54 of a building wall. A door 55 may be hingedly connected to frame 51 and has manually releasable locking means, shown as a snap fastener 57 (FIGURES 4, 5 and 7), to secure the door in closed position. Also secured to frame 51 is a short tubular outlet adapter or receptacle 61, defining an outlet opening 58, and which may extend downwardly and rearwardly at an angle and may be connected to collection conduit 21 by a flexible sleeve 63. A gasket 59, preferably in the form of a sponge rubber plate or the like, is mounted on door 55 so as to engage the receptacle 61 and seal opening 58 against the passage of air therethrough when door 55 is closed and outlet box 25 is not in use.

As shown in FIGURES 4 and 5, receptacle 61 has the corresponding operating end of flexible suction or cleaning hose 28 adjacent the same, and a hand valve unit 65 is attached to the outer end of hose 28 and fits within receptacle 61. A sleeve 84 on hand valve unit 65- may rest against a restricted or shoulder portion 61a of receptacle 61 while the cleaning hose 28 occupies stored position in collection conduit 21. The tubular outer end portion 66 of hand valve unit 65 has a tapered aperture 67 in one side thereof for reception of the usual detent on conventional cleaning implements to releasably main.- tain one end of such cleaning implement within outer portion 66.

The inner end of flexible suction hose 28 is provided with sealing means, shown as a flexible annular gasket or piston 71 (FIGURE 5A) which surrounds and is connected to the outer wall of hose 28 and engages the inner wall of fixed conduit 21 to prevent the flow of air thereby. Spaced from sealing gasket 71, and fixed on hose 28, is an annular resilient wiper ring 72 which engages the inner wall of conduit 21 and, during movement of the hose, effectively removes any accumulated waste material tending to adhere to the conduit wall.

Located on outlet box 25 is a manually operable startstop push button switch 73 which is pressed momentarily to start and stop the pneumatic cleaning system. An override push button switch 74 also may be mounted on outlet box 25 to permit use of the vacuum system as a blower, as will be later explained. A warning light or signal device 75, which is visible through an opening 76 in the door 55 of outlet box 25 when it is closed, indicates when fan motor M and certain other electrical components of the system are energized.

It will be observed in FIGURE 16 that the push button start-stop switches 73 of all three

outlet boxes

25, 26, 27 are arranged in parallel in the circuit, and the warning lights 75 and override switches 74 are arranged in respective series circuits. Thus, all the warning lights 75 are energized when any one of the switches 73 is pressed to start the system and while fan motor M is running. Further, the operation of the system may be independently manually controlled at any one of the outlet boxes.

To control restriction of the air flow through each cleaning hose 28, 29, the hand valve unit 65 on the outer end of each hose preferably is of cylindrical form and has a check valve member or clapper 81 (FIGURES 9-11) pivotally secured to an inner wall thereof. Clapper 81 normally is movable, in response to air flow outwardly along the hose, from an open position (FIGURE 11) to a closed position (FIGURE 9). A gasket or resilient seal 82 on one side of clapper 81 is engageable with a valve seat 83 on the cylindrical wall so that it may seal the outer end of the hose against the flow of air therethrough. Clapper 81 may be locked in closed position by the manually rotatable sleeve 84 which loosely surrounds the cylindrical body of hand valve unit 65 and has an inwardly extending projection 85 thereon positioned in a spiral slot 86 in the wall of the hand valve body. By rotating sleeve 84, projection 85 can be moved along slot 86 and into engagement with the face of clapper 81 (FIGURE 9) to hold the clapper 81 in closed or partially closed position when and as desired. Slot 86 may have straight portions at each end (FIGURES 11 and 12) to restrain projection 85 against accidental displacement in the slot until positive rotation of the sleeve is effected manually, and thus to insure that clapper 81 is locked in a closed position when projection 85 is in engagement with its free end portion.

The central control valve 33 is operative to alternatively and selectively direct air currents inwardly and outwardly along the collection conduits of the system, and the valve housing 37 thereof (FIGURES 13 and 14) defines a first or upper compartment 91, separate portions of which are connected to fan outlet conduit 38 and exhaust conduit 39. The first compartment 91 communicates, at times, with a second compartment 92 of housing 37 by means of an opening or passage 93. Common collection conduit 24 is connected to one end of second compartment 92, and air inlet conduit 36, from collection chamber 34, is connected to the opposite end of compartment 92. Compartment 92 also has an auxiliary passage or opening 94 therein communicating with the atmosphere.

Supported between

compartment

91, 92 on a rotatable or pivot shaft 95, is a double clapper 96 which is operative to occupy a first or blow-out position (FIGURE 13) providing communication between conduit 38 at the outlet side of fan 32 and the common collection conduit 24, and also providing communication between the inlet conduit 36 of collection chamber 34 (FIGURE 3) and the atmosphere by way of opening 94 (FIGURES 13 and 14). Clapper 96 also is operative to occupy a second or suction position (FIGURE 14) providing communication between conduit 38 at the outlet side of fan 32 and exhaust conduit 39, and also providing communication between common collection conduit 24 and the inlet conduit 36 of collection chamber 34.

The electrical control device 41 embodies means to rotate clapper 96 of central control valve 33 between the aforementioned first and second positions and comprises a gear motor 101 (FIGURES 2, and 16) provided with a cam 102 mounted on its drive shaft 103. Pivot shaft 95 of double clapper 96 has a fixed crank arm 104 extending therefrom with a cam follower 105 thereon held in contact with cam 102 by means of a spring 106. Spring 106 also biases double clapper 96 toward the blow-out position (FIGURE 13) when cam 102 moves away from follower 105. Cam 102 has a projection 107 thereon which engages a spring lever 108 of a gear motor switch 109. Switch 109 is normally biased toward open position and located in series with switches 74, the operation of which will be later explained.

The control system of the pneumatic cleaning system may best be described by reference to the electrical circuitry of FIGURE 16. The electrical system may include a transformer 111 whose primary winding 112 is connected by a first set of conductors 113, 114 to a primary power supply P. Fan motor M also is connected to power supply P by way of conductors 115, 116, 117 and a switch 118.

Conductors

115, 119, 121, 122, the manual override switches 74 and the gear motor switch 109 serve, at times, to connect gear motor 101 to power supply P. When any one or more of the normally closed override switches 74 are open, this prevents the gear motor switch 109, when closed, from completing the circuit between gear motor 101 and the primary power supply P. However, during use of the system for suction cleaning, override switches 74 are closed.

The secondary winding 123 of transformer 111 supplies low voltage to the control components of the electrical system which actuate fan motor M and gear motor 101.

Switch 118 and a switch 129 are parts of an electromagnetic latching relay 124 whose coil is connected by

conductors

125, 126, 127, 128 and manual push button start-stop switches 73 to the secondary winding 123 of transformer 111. As shown, switches 73 are connected in parallel to the coil of latching relay 124 so that, by manually pressing and closing any one or more of switches 73, the coil of relay 124 is energized.

As will be later explained, with alternate closings of a switch 73, relay 124 is activated and, with intervening closings of a switch 73, relay 124 is inactivated. When relay 124 is active, switch 129 completes a circuit through

conductors

131, 132, 133, 127 to connect the outlet box warning lights 75 to the secondary winding 123 Whenever fan motor M is energized.

When push button start-stop switch 73 on any one of

outlet boxes

25, 26, 27 is closed, in addition to completing the circuit to the coil of latching relay 124, a Second circuit is also completed to a heating coil of a vacuum tube delay-relay 136 through conductors 126, 127, 134, and the secondary winding 123. The delay interval of relay is determined by the time required to heat coil 135 sufficiently to close a pair of normally open contacts a, b in the vacuum tube of relay 136. When closed, contacts a, b energize gear motor 101 through

conductors

115, 119, 141, 142 and 117.

It should be noted however that a switch 73, in order to energize motor 101, must be held closed for a sufficient period of time to permit the heating coil 135 to close contacts a, b and move projection 107 on cam 102 away from spring lever 108 and close gear motor switch 109. At this time switch 109 will take over to energize motor 101 and switch 73 may be released, allowing coil 135 to cool and permitting contacts a, b to open, breaking the initial circuit to the gear motor by way of vacuum tube relay 136.

Gear motor 101 then continues to operate until cam 102 has completed a revolution and projection 107 again engages spring lever 108 to open switch 109. As cam 102 moves away from cam follower 105, spring 106 moves double clapper 96 of central control valve 33 to the blow-out position of FIGURE 13, thus establishing communication between the outlet side of fan 32 and the common conduit 24 to direct blowing air into, or produce positive air pressure in, collection conduits 21-23.

The operation of latching relay 124 can best be described by reference to FIGURES 17 and 18. Assuming relay 124 is inactive as shown in FIGURES 16 and 17, when any one of the push button switches 73 is actuated manually to energize the coil of relay 124, a magnet 151 attracts and draws a pivoted spring-biased armature 152 into contact therewith. A projecting finger or trigger 153 on armature 152 is thus moved against a downwardly extending spring-biased keeper 154 to displace it in FIGURE 17 from engagement with the end of a projection 155 on a spring-biased pivotally mounted latch 156. Such displacement of keeper 154 moves a switch contact point 157 of each

switch

118, 129 into engagement with a respective fixed switch contact point 158 to close each

switch

118, 129. When the corresponding push button switch 73 is released to break the circuit to the coil of relay 124, armature 152 moves away from magnet 151, but the downwardly extending keeper 154 is retained by projection 155 to lock the switch contact in closed position as in FIGURE 18.

To

open switches

118, 129 thereafter, any one of the push button switches 73 is again pressed and held closed momentarily to again move armature 152 into engagement with magnet 151, whereupon trigger 153 engages projection 155 to displace latch 156 and permit keeper 154 to move in response to the spring 154a and thereby open the

contacts

157, 158 of each

switch

118, 129

Method of operation For the purpose of description of the method of operation of the cleaning system, it will be assumed that flexible hoses 28, 29 occupy the positions shown in FIGURES 1, 4, and 5A and that the clapper operating projection 85 of each hand valve unit 65 occupies the inactive position of FIGURE 11. Further, it is to be assumed that clapper 96 of central control valve 33 occupies the suction position of FIGURES l4 and 15. Thus, upon the operator momentarily closing the push button switch 73 of any one of the outlet boxes 25-27 for a sutficient period of time to activate relay 136, fan motor M and gear motor 101 are successively energized in the manner heretofore described.

Initially, suction pressure will be present in all of the collection conduits 21-23, and the clapper 81 of each hand valve unit 65 will thus occupy the open position of FIGURE 11. However, when cam 102 (FIGURE 15) moves out of engagement with follower 105, spring 106 moves double clapper 96 to the blow-out position of FIGURE 13, thus producing a blowing or positive pressure in each conduit 21-23.

Assuming that the doors 55 of

outlet boxes

26, 27 are closed, the operator opens door 55 of outlet box 25, withdraws the hand valve unit 65 of the hose therefrom, and rotates sleeve 84 of the hand valve which is stored in the outlet box with clapper 81 in locked position, to unlock the face of clapper 81. Switch 73 of the outlet box 25 is then actuated to start motor M, fan 32, and gear motor 101 to produce positive pressure in the conduits 21-23 of the system. The closed door 55 of outlet box 26 seals the outlet against the escapement of blowing air and thus restrains the hose 29 against being forced outwardly through the outlet box. Due to the positive pressure produced in the conduits, the valve clapper 81 of hose 28 will be moved to the closed position of FIGURE 9.

The positive air pressure in conduit 21 will thus extend or impa1t outward movement to flexible hose 28 through outlet box 25 until wiper ring 72 engages the inner end of receptacle 61 of FIGURE 5, or until the cam 102 of FIGURE 15 again engages follower 105 and returns double clapper 96 to the suction position of FIGURE 14, whichever occurs first. Thus, suction pressure is again produced in each conduit 21-23 by fan 32, and this causes the clapper 81 of the hand valve unit 65 on hose 28 to open (FIGURE 11). The operator may then insert into and connect one end of any desired cleaning implement to the outer end portion 66 of the hand valve unit 65 on flexible hose 28 to clean the desired area or surfaces by suction.

At any time after hose 28 has been extended in the manner last described, the operator may partially or fully close the corresponding clapper 81 by rotating sleeve 84 (FIGURES 9-11) relative to the body of the hand valve unit 65, whereupon the negative or suction pressure in conduit 21 will retract the hose 28 into conduit 21 where it is stored with the hand valve 65 in a locked, closed position, as seen in FIGURE 9. Of course, if the operator wishes to retract only a relatively short length of the hose 28 into conduit 21, the operator returns sleeve 84 to the position of FIGURE 11 at any desired instant and may then resume the suction cleaning operation.

Although the operator may desire to leave the hose partially extended and then deenergize fan motor M, the hose normally would be fully retracted into the corresponding outlet box 25 and conduit 21 before denergizing fan motor M.

The fan motor M is deenergized, when desired, simply by momentarily actuating the adjacent push button switch 73 to inactivate latching relay 124, thereby opening

switches

118, 129. Normally, the operator would only hold the corresponding switch 73 is closed position for a very short time when stopping motor M, so the heating coil (FIGURE 16) would not heat sufficiently to close contacts a, b of relay 136, and thereby avoiding energizing gear motor 101 at that time. However, in the event that the corresponding switch 73 were held closed for a sufficient period to cause contacts a, b to close, gear motor 101 would simply complete a cycle and then cease rotating if the corresponding switch 73 has been released. The method of operation then could be repeated substantially as heretofore described.

As stated earlier, in addition to being used for suction cleaning, the cleaning system of the present invention also may be used for blowing cleaning; i.e., for blowing lint, dust and the like off of surfaces to be cleaned, or for operating various pneumatic implements such as paint sprayers, deodorant sprayers, etc. When the operator wishes to utilize the cleaning system as a blower, the operator need only open an override switch 74 associated with any one of the outlet boxes 25-27 to thereby render switch 109 ineffective to energize motor 101 in the normal manner heretofore described.

Thereupon, the desired push button start-stop switch 73 may be closed by the operator to effect energization of fan motor M and gear motor 101 and thus effect extension of the corresponding flexible hose (hose 28 in this instance) in the manner heretofore described. However, motor 101 is only energized during a partial revolution of cam 102 driven thereby because, when the contacts a, b of vacuum tube relay 136 are permitted to open by the cooling of heating coil 135 consequent to the opening of switch 73, gear motor 101 will no longer be energized, even though switch 109 will have been released and moved to closed position as the projection 107 on cam 102 moved out of engagement with arm 108. This is due to the fact that gear motor switch 109 is in series with all the override switches 74.

It follows that, when the operator has held a push button start-stop switch 73 closed for a suflicient period of time to insure that cam 102 has moved out of engagement with follower 105, and then releases the corresponding switch 73, cam 102 will remain in the position last described and spring 106 then urges double clapper 96 of central control valve 93 to the blow-out position of FIGURE 13. The double clapper 96 thus remains in the blow-out position, but since the clapper 81 of the corresponding hand valve unit 65 is then held in closed position by the positive pressure in the corresponding flexible hose, means is provided for maintaining the hand valve clapper 81 in open position while the corresponding flexible hose is being used as a blower.

As shown in FIGURE 12, the means for maintaining the hand valve clapper 81 in open position, in opposition to the blowing air current in the flexible hose, may take the form of a blowing adapter member or attachment 1-60 and may comprise an elongate cylindrical body 161 adapted to fit in the outer end portion of the corresponding hand valve unit 65 in place of the usual suction cleaning elements used with the hand valve unit 65.

Blowing adapter member may be releasably secured in the corresponding hand valve unit 65 by means of a spring-biased detent 162 which enters aperture 67 in the wall of the hand valve body. Other implements may be conveniently connected to the outer portion of cylindrical body 161 or the blowing adapter member 160, per se, may serve also as a cleaning implement or the like by providing a tapered nozzle portion 163 on the outer end of the body 161 as shown in FIGURE 12, thus providing a relatively small air discharge nozzle opening 164 on the outer end of cylindrical body 161. In order to maintain clapper 81 in open position, the inner end of cylindrical body 161 may be partially closed and has a relatively small tubular portion 165 communicating therewith in eccentric relation to the body 161, and which fits within the opening defined by valve seat 83 so as to engage and move clapper 81 to open position when the body 161 is inserted manually in the outer end 66 of the 9 corresponding hand valve unit 65. Thus, the reduced tubular portion 165 will maintain clapper 81 in the open position during use of the system as a blower.

It is apparent that, following the use of the system as a blower, adapter 160 may be removed from the corresponding hand valve unit 65 and the previously opened override switch 74 may be closed to return cam 102 and central control valve clapper 96 to the positions shown in FIGURES 14 and 15. Thereupon, the system may be used further as a suction system or the corresponding flexible hose may be returned to stored position in the corresponding collection conduit in the manner heretofore described, after which any one of the switches 73 may be closed momentarily to stop fan motor M.

Various other timing mechanisms may be used to regulate central control valve 33 and to maintain double clapper '96 in the blow-out position without departing from the scope of the invention. By utilizing the disclosed gear motor 101 and cam 102, the size of the cam and speed of rotation of the gear motor may be varied to hold the control valve clapper 96 in the blow-out position for different periods of time to extend desired amounts of hose from an outlet box prior to moving the'valve clapper 96 to the suction position.

By utilizing a check valve, such as clapper 81, on the outer end of each hose 28, 29, it is not necessary to manually open the valve exactly when the extension of the hose is complete, since the valve will automatically open upon reversal of the air flow in the conduits as effected by cam 102 and clapper 96.

The bleeder valves are provided to control the rate of extension of the flexible hoses 28, 29 from their associated

outlet boxes

25, 26. The bleeder valves 31 in conduits 21, 22 are preferably located at points intermediate the length of the respective suction hoses 28, 29 when they are in retracted position. Each bleeder valve is a form of check valve and may comprise a T-shaped pipe fitting (FIGURE 6) having an eccentrically positioned opening 171 in the branch leg 172 thereof. Rotatably secured by a pin 173 in the branch leg 172 is a plate or disc 174 having an eccentric opening 175 therein adapted to register with opening 171.

A flexible clapper element or flap 176 is secured to the exposed side of disc 174, as by a brad 177, and overlies opening 175 thereof to prevent the inward flow of air therethrough. By adjustably rotating disc 174 so that its opening 175 partially or completely registers with a portion of opening 171, the discharge of air therethrough can be varied, thus varying the positive pressure in the associated conduit and hose.

By positioning bleeder valves 31 intermediate the length of hoses 28, 29 (FIGURE 1), these bleeder valves have no effect upon the initial rate of movement of each hose from its retracted position by positive pressure in the corresponding conduit. However, as the sealing gasket or piston 71 (FIGURE SA) on the end of either hose 28, 29 passes a bleeder valve 31, the corresponding bleeder valve permits some air pressure to escape from the respective conduit 21 or 22 to decrease the pressure exerted against the hose and thereby reduce its rate of outward movement. A reduced speed of extension of the hose may be particularly desirable where an outlet box of the system is positioned at the lower end of a conduit as is the ease with outlet box 26 in FIGURE 1, or where an outlet box occupies an overhead position, such that the weight of the hose assists in its extension. The bleeder valve 31 in the common collection conduit (FIGURE 1) adjacent enclosure A may be desirable in instances in which it is desired to regulate the positive pressure which may be effective in the entire vacuum cleaning system. However, suction pressure in the conduits holds each flap 176 in closed position so there is no inward flow of air through the corresponding bleeder valve.

The flexibility of wiper ring 72 and seal 71 is such that, although they may normally prevent each hose 28, 29 from being blown entirely out of the

respective outlet box

25, 26 by engaging the inner end of the corresponding tubular receptacles 61 (FIGURES 4, 5, 8 and 9), an operator may readily distort and/or compress the ring 72 and seal 71 on either hose 28, 29 by manually twisting and/or pulling on the hose to force the ring and seal through the restricted inner end of the corresponding receptacle and to thereby remove the entire hose from the corresponding receptacle and outlet box. This may be desirable in the event that one or more outlet boxes, such as outlet box 27 (FIGURE 1) and its conduit 23, is not equipped with its own hose and one of the hoses 28, 29 is to be used at such outlet box 27.

In the drawings and specification there have been set forth preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. A method of manipulating a flexible suction hose positioned for longitudinal movement within a conduit of a vacuum cleaning system and capable of telescopic retractable storage within the confines of the conduit with its outer end proximate the conduit outlet, said method comprising the steps of:

(a) creating a pressure in said conduit above atmospheric pressure, and

(b) extending the hose outwardly of the conduit outlet into an area to be cleaned under the influence of the pressure.

2. A method as defined in claim 1 including the subsequent steps of:

(a) changing the pressure in said conduit to provide a reduced pressure below atmospheric pressure, and

(b) retracting the suction hose from its extended position in said area telescopically into said conduit for storage under the influence of the reduced pressure.

3. A method as defined in claim 1 wherein the step of creating a pressure above atmospheric in said conduit includes the steps of:

(a) initiating a flow of air outwardly along said conduit toward its outlet, and

(b) restricting the outward flow of air through the flexible suction hose.

4. A method as defined in claim 2 wherein the step of changing the pressure in the conduit to a reduced pressure includes the steps of:

(a) initiating a flow of air in said conduit and hose in 211 direction away from the outlet of the conduit, an

(b) restricting the flow of air through the flexible suction hose.

5. A method of manipulating a flexible suction hose normally telescopically retractably stored within a conduit of a vacuum cleaning system, said hose having an outer end located adjacent an outlet of said conduit when in retracted position and an inner end located within said conduit, said method comprising the steps of:

(a) directing air flow in said conduit in a first direction toward its outlet,

(b) restricting the outward flow of air through the outer end of said hose to create a positive pressure in the conduit and longitudinally extend the hose from the outlet of the conduit,

(c) reversing the direction of air flow in said conduit while permitting substantially unrestricted flow of air into and through said hose to create suction currents therethrough for cleaning, and

(d) restricting the inward flow of air through the outer end of the hose to create a negative pressure in said conduit and retract said hose telescopically into said conduit for storage.

6. A vacuum cleaning system having a retractable and extensible flexible suction hose telescopically positioned within and normally retractably stored within a conduit of the system with an outer end of the hose proximate the conduit outlet, and means associated with the system for producing a positive pneumatic pressure in said conduit to extend the suction hose from the outlet of the conduit into an area to be cleaned.

7. A vacuum cleaning system as defined in claim 6 wherein said means is also operative to produce a negative pneumatic pressure in said conduit to retract the hose into the conduit for storage.

8. A vacuum cleaning system as defined in claim 7 wherein said telescopically positioned vacuum hose has an inner end movable longitudinally in said conduit, sealing means associated with said inner end to substantially prevent the flow of air between the outer Wall of said hose and the inner wall of said conduit, whereby said sealing means acts as a piston surface on said hose to assist in moving said hose longitudinally in said conduit in response to pneumatic pressure in the conduit.

9. A vacuum cleaning system as defined in claim 8 wherein said sealing means includes a flexible gasket surrounding said hose and engaging with the inner wall of said conduit, and wiper means positioned on said hose and spaced from said gasket to contact the inner wall of said conduit to remove accumulation of waste material thereon during extension and retraction of the hose.

10. A vacuum cleaning system as defined in claim 7 wherein said pneumatic pressure producing means includes an air impeller communicating with an inner end of said conduit, control means operatively associated with said air impeller for selectively directing air flow produced thereby in a first direction outwardly of said conduit toward said conduit outlet and in a second direction inwardly of said conduit away from said conduit outlet, and means associated with the hose for restricting the flow of air therethrough to create said positive pressure during said outward flow of air and said negative pressure during said inward flow of air.

11. A vacuum cleaning system as defined in claim 10 wherein said control means includes a valve located in said conduit and movable between a first position connecting the outlet of said air impeller to said conduit to direct air currents in said first direction, and a second position connecting the inlet of said air impeller to said conduit to direct air currents in said second direction, and means for retaining said valve in said first position for a predetermined period of time to extend the hose from the conduit when the flow of air through the hose is restricted and for thereafter automatically moving the valve to said second position to produce suction currents through said conduit for cleaning.

12. A vacuum cleaning system as defined in claim 10 wherein said restricting means is located on the outer end of the hose and is arranged to close said outer end in response to outward movement of air therethrough and to open said outer end in response to inward movement of air therethrough, and manually manipulable means to retain said outer end closed.

13. A vacuum cleaning system as defined in claim 12 including means associated with said restricting means to prevent closure of the outer end of said hose during the passage of air outwardly therethrough, whereby said vacuum cleaning system may be used to blow air into an area.

14. A vacuum cleaning system as defined in claim 10 including bleed valve means in said conduit located intermediate its length to vary positive pneumatic pressure in said conduit to control the speed of extension of said hose from the conduit outlet.

15. A vacuum cleaning system as defined in claim 14 wherein said bleed valve means is also located intermediate the length of said hose when the hose is in retracted position in said conduit to reduce the speed of movement of said hose during extension from the con duit after its initial outward movement.

16. A vacuum cleaning system having a retractable and extensible flexible suction hose telescopically positioned within and normally retractably stored within a conduit of the system, with the outer end of said hose adjacent an outlet of the conduit, means for creating an air flow in said conduit, control means associated with said conduit for selectively directing said air flow in a first direction toward the outlet of the conduit, and in a second direction away from the outlet of the conduit, and means associated with the hose for restricting the flow of air therethrough to create pneumatic pressure in said conduit suflicient to extend the hose from and retract the hose into the conduit for respective use and storage.

17. A vacuum cleaning system as defined in claim 16 including at least on additional conduit having an outlet and an additional flexible suction hose telescopically positioned and normally retractably stored therein, said additional hose having means associated therewith for restricting the flow of air therethrough, and wherein each of said conduits is provided with means for sealing the outlet thereof when not in use, and wherein said means for creating an air flow in said conduit and said control means are also associated with the additional conduit for selectively directing the flow of air therethrough when said additional conduit and hose are in use.

18. A vacuum cleaning system as defined in claim 17 wherein said control means includes means located at each outlet of said conduit and said additional conduit for independent operational control of the vacuum cleaning system.

References Cited UNITED STATES PATENTS 1,597,312 8/1926 Cesa.

2,623,234 12/195'2 Brown 15315 XR 3,278,949 10/1966 Whitaker 134-168 XR 3,353,996 11/1967 Hamrick 134-21 MORRIS O. WOLK, Primary Examiner D. G. MILLMAN, Assistant Examiner US. Cl. X.R.

62221 UNL E STATES PATENT OEFICE Patent: No. 6 859 Dated Issued September 2 1969 lnvontoflu) T. Humrick It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

The assignee should be Jet Line Products Incorporated-- instead of "J L Products Incorporated". Column 7, Line 74, "is"sho1'1'ldbo -in.

SiGn-ED AND SEALED FEB 1 7 I970 WILLIE E. somrm. 3'8. Mu Offi Commissioner of Patents