Патент USA US2050332код для вставки
Aug. 11, 1936. O R H_ JORDAN '- 2,050,332 HEATING DEVICE Filed Feb. 21, 1954 WITNESSES: 8” W Y woo 2 Sheets-Sheet 2 INVENTOR I Richard H Jordan. Patented Aug. 11, 1936 2,350,332 UNITED STATS YET FFlCE 2,050,332 HEATING DEVICE Richard H. Jordan, Spring?eld, Mass, assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application February 21, 1934, Serial No. 712,349 6 Claims. My invention relates to electrical heating de vices and it has particular relation to electric hand driers and other comparable devices which produce a stream of heated air for direction against objects which are to be dried. In order to eliminate the necessity for towels (Cl. 219—39) taken .on lines III-III, IV—-IV and V-V of Figs. 1 and 2; Fig. 6 is a plan view of the improved heating unit which forms a part of the drier shown in the preceding ?gures; Fig. 7 is a view in side elevation of the heater in business of?ce, public, and other washrooms, of Fig. 6; there have, in recent years, been developed me chanical driers which typically comprise an elec tric heater through which a motor-driven blower discharges air for direction against the hands and resistance-wire supports which forms a part of 10 the heater of Figs. 6 and 7. face of a user. All devices of. this character with support spacers incorporated in this heater; which I am familiar have, however, been subject to certain limitations and disadvantages, espe 15 cially when considered for residence installation, and it is to the overcoming of such disadvantages and limitations that the present invention is di rected. 'One object of my invention is to provide an 20 electrical hand drier which is compact in design and artistic in appearance. Another object of my invention is to provide a construction for drying devices .of the type under consideration which facilitates an adjustment of 25 the direction of discharge of. the heated air. A further object is to protect the heating unit of the drier from damage upon failure of the blower to operate. Another object of my invention is to improve 30 the starting characteristics of driving motors of the single-phase induction type. A still further object is to protect the drier con trol switch from damage in the event of excess movement of the operating foot treadle. Another object of my invention is to provide a construction for hand-driers which facilitates a concealment of the ?oor-fastening means. An additional object of my invention is to im prove the construction of electrical heating units 40 adapted for use in hand driers and other com parable heating devices. My invention itself, together with additional objects and advantages thereof, will best be un derstood through the following description of a 45 speci?c embodiment when taken in conjunction with the accompanying drawings in which: Figure 1 is a view in side elevation of the im proved hand drier of my invention, a portion of 50 the exterior casing being cut away to indicate the internal construction; Fig. 2 is a view in end elevation of the device of Fig. 1, a portion of the exterior casing also being cut away; 55. Figs. 3, 4 and 5 are section views respectively Fig. 8 is a side elevational view of one of. the Fig. 9 is a view in end elevation of one of the Fig. 10 is a view in side elevation of the heater protecting centrifugal switch which is responsive 15 to the speed of the blower shaft; Fig. 11 is a view in end elevation of the rotat able composite-ring assemblage which forms a part of. the centrifugal switch of Fig. 10; Fig. 12 is a View in end elevation of the sta tionary frame and contact carriage comprised by 20 this switch; and, Fig. 13 is a simpli?ed or schematic diagram showing one preferred manner in which the .elec trical devices comprised by the improved hand drier of my invention are interconnected with 25 each other for energization from a power circuit. Referring to the drawings, and particularly to Figs. 1 and 2 thereof, the hand drier of my inven tion there shown comprises an air blower Ill which is supported in an angle-iron frame com 30 prising four upright members l2, suitably braced and interconnected by cross members certain of which are shown at M and It. Underneath the blower it, which may be of. any one‘ of a number of well-known types now commercially available, is mounted an electric motor 20 which drives the blower by means of an endless belt 22 intercon necting a pulley 2! carried by the motor with a cooperating pulley 24 attached to one end of the blower shaft H2. This particular arrangement of the blower and its driving motor, when of the form and relative proportions shown, has the advantage of reducing the thickness of the com plete drier assemblage and, hence, in the interest of compactness of design, is the one which I pre 45 fer to utilize. In the cylindrical air-discharge passage 28 of the blower is positioned an electrical heating unit, the construction of which is more completely 50 shown in Figs. 6 to 9, inclusive. In Figs. 1 and 2 only the protruding top portion 36 of this heater is represented. Operation of the drier is con trolled by means of a switch 80, mounted on the angle iron frame work. While, as shown, the 55, 2 2,050,332 switch is actuated by means of a foot treadle 83, it will be understood that, if desired, other ac tuating means may be used to effect its operation. Surrounding the draft-producing and air heating equipment just described is a suitable casing which, as shown, comprises two identical halves 36, preferably constructed of sheet metal, which, as may best be seen by an inspection of Fig. 5, are interconnected by means of. metal spacer strips 38 and 39. It will be observed that each edge of the spacing strips 38 and 39 inter ?ts between a ?anged portion 48 of the casing member 36 and a soldered-on portion 139 which completes a groove of the proper dimensions and 15 character. This exterior casing completely covers and hence conceals the draft-producing mecha nism and in addition forms, above a partition member to, a pressure chamber or compartment into which the heated air is blown. From this 20 chamber the warm air is discharged for drying. purposes through a suitable opening in the top which it escapes through the outlet ?xture 42 for direction against the objects to be dried. The discharge ?xture 1%2 is adjustably mounted to permit the direction of the stream of warm air to be changed by the manipulation of handles 58 which protrude from the pressure chamber sides. When, as illustrated in the drawings, the opening occupies the central or mid-position in its range of adjustment, the heated air will be dis charged in a vertical direction from the top of 10 the casing, The discharge ?xture [l2 comprises a frame 64 which is supported, through a pair of sheet metal strips 8%, from a shaft 5%, to the protruding ends of which shaft are attached the adjusting han 15 dles 58. These supporting strips may be secured to the shaft by any suitable means such as the pairs of cooperating nuts 62, and have ?xed to their upper ends, as by welding, the ?xture frame 6-2. This frame carries a plurality of round bar 20 members 65 arranged in parallel or grille-like fashion over the discharge opening. thereof. In order that the semi-circular path of ad? It is found preferable to completely assemble the exterior casing before ?tting the same down justment' travel of the warm-air outlet ?xture 25 over the blower and driving motor unit to which 1'52 will be closed with the exception of the'area, the two casing halves 36 may be secured by of the ?xture, a thin and ?exible metal strip Till, shown in Figs. 3 and 4, through an opening in means of screws fill which ?t into threaded holes 45 suitably positioned in certain members of the which the frame 64 of the ?xture protrudes, is slidably mounted in appropriate slots formed frame of the blower units. To cover the heads by the raised edges l2 of the opposing top por 30 of these attaching screws lid, and to otherwise im tions of the casing halves 36 and specially ?anged prove the external appearance of the drier, metal metal strips “it which are welded thereto. It will strips 52 are vertically positioned in the manner shown along the centers of the two sides of the be understood that if desired the single strip with casing, they being. ?tted in a notch 53 at their the opening cut therein may be replaced by two separate strips which are respectively attached to 35 lower ends and held at their upper ends by the the two ‘ends of the ?xture frame 64. As the po washer or bearing members all of the outlet ?x ture adjuster. To hold the casing halves together sition of the outlet ?xture 42 is changed, the during the assembly operation and to further ?exible strips ‘it will follow in the grooves provided therefor in the semi-circular top section strengthen the complete assemblage at the up of the casing, and at all times maintain the 40? per portion thereof, cross braces lit are provided. To isolate any vibration which may originate in pressure chamber closed with the exception of the ?xture itself. the hand drier, rubber supports 86 secured to the outlet Manipulation of either of the handles 58 thus feet of the blower mechanism framework in the‘ causes the outlet ?xture [12 to change its posi manner shown are provided to effect a resilient 45 contact with the floor or other surface upon which the drier may be set. These supports 86 protrude a short distance below the lower edge of the exterior casing 36, and thereby separate it fromdirect contact with the supporting surface. 50 While any suitable means for effecting the re quired air-tight partition between the upper and lower compartments of the blower may be uti—' lized, I have found that a layer of felt represented at lit, the contour of which is such that it inti 55 mately contacts the sides of the surrounding cas ing, in the manner best indicated by Fig. 5, is ex ceedingly effective. To secure this layer of felt in place, a thin plate of sheet metal iii may be clamped down over the top of the felt by means 60 of screws "13 which secure it to the structural members of the blower supporting framework therebeneath. In order that air for discharge through the blower into the upper or pressure compartment 65 may be admitted into the space occupied by the blower structure Ml, which draws it through the open spaces in the spoked end bracket l M of the blower, suitable openings HQ may be made in each end of the lower portion of the casing in .the manner shown. During operation of the drier, the air from the room is drawn in through these openings llD, discharged by the blower ill, through the heating coils 95 (Fig. 5) positioned in the outlet 28 of the blower, into the pressure 75 chamber in the upper portion of the casing from tion in the semi-circular space between the up per portions-of the co-operating casing halves 35S and thereby changes the direction of air dis charge. To limit the travel or restrict the range of this adjustment, stop members, in the form of angle pieces El welded to the side of the cas 50 ing, are adapted to make contact with one of, the strips (if! when either limit of travel is reached. To prevent chattering of the ends of the flexible strip iii which protrude below the rim l2 of the casing halves, the welded on strips 13 may be ex 55 tended down to an intermediate elevation as shown in Fig. 4. It will be apparent that through the use of this improved construction, adjustment in the posi tion of the outlet ?xture 42 may be made with but little effort on the part of the operator, since the friction to movement of the ?xture and the ?ex ible sealing strip attached thereto may be re duced to a low value. > Energizing current for the blower driving motor and the air heater is derived through a connection. with the lighting or other power sup ply circuit established by means of a ?exible cord l5 terminating in a plug connection 76 which may be inserted into a wall or other outlet ?xture. As shown, the cord enters the drier casing through a hole in the bottom of metal strip 38, in which hole an insulatitng bushing ‘ll is placed. The switching device at, utilized to control the operation of the drier, is illustrated as being of 60 “ 3 2,050,332 the so-called “momentary contact” type, it com pleting an energizing circuit only as long as an operating lever 8| thereof, which is maintained in the upward position shown by resilient means incorporated in the switch construction, is con tinuously depressed. Depression of this lever is effected by means of the foot treadle 83, which protrudes to the outside of the casing through a suitable slot 84 cut in the lower endvof the spacer 10 strip 39. Connection between the treadle and switch lever is established by means of a spring 85, which is of su?icient rigidity to transmit switch-actuating movements. The elongating characteristic of the spring allows, without in jury to any of the associated mechanism, the treadle to be further depressed after the switch arm 8| has reached its limit of downward travel. While it will be understood that any suitable air heating unit may be utilized in the hand drier of my invention, the unit which I prefer to utilize because of economy of construction and ease of replacement, is illustrated by Figs. 6 to 9, inclu sive, which heater has already been referred to in the explanations of the showings of the com plete drier assemblage. One desirable feature of such a heater is that the heating conductors posi tioned in the passage through which the air to be heated is blown shall be uniformly distributed throughout that passage and shall not unduly ob 30 struct the flow of air therethrough. Thus, it is preferable to position the coils 99 of heating wire in some manner such as is indicated by the show ing of Fig. 6 which is a top or plan View of the improved heating unit of my invention which, as before explained, is positioned in the cylindrical outlet passage 28 of the blower Ill. In the construction of this heating unit, a cylin drical shell 39 is formed from sheet metal, a ?at strip of which is ?rst cut to the desired dimensions 40 and then bent into the circular contour of the cylinder. In this position the cooperating or overlapping edges of the sheet are spot welded or otherwise secured to each other, this junction being indicated in Fig. 7 by the area of overlap 92. In the original ?at sheet are also cut two parallel oblique slots 93 and 94, each of which in the assembled cylindrical shell 30 are spiral in form, as also indicated in Fig. 7. The cylindrical shell having been assembled, porcelain heating wire supports 96, a side view of one of which is shown in Fig. 8, are then inserted in the spiral slots 93 and 94, they being spaced from each other by means of suitably slotted spacers 98 constructed of sheet metal, an end view of one of which spacers is shown in Fig. 9. At the bottom of slot 94 and at the top of slot 93 are positioned terminal bolts 97 which secure the two ends of the coil of heater wire 96, which coil is progressively threaded among the specially GO spaced supports 96 in the manner indicated in Fig. 6. Energizing-circuit connections with the coil are made through the terminals 91 by means of conductors 95, which are threaded through a porcelain bushing 99 carried by a top ring mem ber I08 which surrounds and is secured to the upper portion of the ‘cylindrical shell 30 by an attachment effected by means of bolts I63, to a pair of shell ears I62. For greater ease in assembly of the heater unit, the coil of heater wire 9i} may be threaded through the insulator supports 96 before their insertion into the slots in the cylindrical shell, in which case, this preparatory threading operation may readily be accomplished by arranging the insu , lators which are to go in each of the two spiral slots in parallel lines on a ?at surface, which lines are spaced substantially by the diameter of the shell, and then threading the coil of heater Wire in zig-zag fashion progressively through these supports. When spacedly placed in the two opposing slots, the resulting diversi?cation of the individual branches of the heater coil length shown in Fig. 6 will obtain, and a stream of air in being blown through the cylindrical shell 30 will be uniformly and effectively heated without 1O receiving undue physical obstruction. In installing the heater unit in the cylindrical discharge opening 28 of the blower III, it may be secured to the top rim thereof by means of screws I06 which are accommodated by the holes III‘! 15 in the heater rim I00. In order to obtain the desired effectiveness of a heater adapted to warm air which is'blown rapidly therethrough, it is necessary to operate the resistance wire or conductor at such a high 20 current that should for any reason the draft of air be discontinued, the conductor will attain such excessively high temperatures as to burn out. Consequently, in a device of the type under con sideration, should for any reason the blower dis; continue its operation or fail to start upon ener gization of the heater unit, the unit will be burned out. To protect against damage from this cause is one objective of the present invention. In effecting such protection, I dispose in the energizing circuit of the heating unit, a centrif ugal switch which is responsive to the speed of the blower shaft. This switch, which is generally indicated in the showing of Fig. l at III), requires that the blower I6 be brought up to speed before 35 the heater can be energized and also serves to interrupt the heater circuit as soon as the blower speed decreases to a predetermined low value. ~ In the improved hand drier of my invention, ‘I prefer to mount this switch directly on the shaft II 2 of the blower inside of the end bracket H4 in a manner shown in greater detail by Fig. 10. While the switch itself may be of any suitable construction responsive to changes in speed of the shaft, the type which I prefer to utilize is 45 that which is more completely shown and de scribed in United States Patent 1,305,084, which issued May 27, 1919, to John B. Hansell. As illustrated in Figs. 10, 11 and 12, this switch comprises a composite ring H6, sensitive 'to 50 changes in the centrifugal force acting thereon, mounted directly upon the blower. shaft II2, a base plate H8, attached, by means of screws I2IJ, to the end bracket H4 of the blower, and a car riage I23 mounted in suitable slides on the base 55 plate in a manner to move in a vertical direction therein. This carriage supports, by means of an insulating material bar I25 attached to the lower end thereof, a pair of contact bridging members I24 and I25 which are respectively adapted to selectively make connection with two pairs of stationary contact members I27 and I28 carried on an extension of insulating material I30 which is ?xed to the lower end of the base plate II8. Connections with the circuits to be controlled are made by attaching the conductors, as by screws I29, to these stationary contact members. Changes in the effective diameter of the com posite ring I I6 effect an actuation of the carriage through the medium of suitable operating lugs I38 and I39 which protrude from the upper por tion of the carriage and embrace the ring in the manner indicated by the side View of Fig. 10. The ring comprises, as is best indicated by Fig. 11, 4 2,050,332 a-nplurality of crescent-shaped'movable members 142- symmetrically pivoted, at their ends I45, to a 'baseplate I43 which is directly attached to the shaft I I2,.each member being biased inwardly by a;.spring .Ilil. These-members Hi2 nest snugly .tion .against burnout due- toaccidental stoppage or failure of the blower to start is in this man :ner‘ obtained. witheach'other because ofa lateral offset 'in each of them whereby the pivoted-end‘lies closely For use with the alternating-current supply circuits which are at the present time almost universal in locations where ‘it is desired to in stall hand driers and other comparable motor adjacent to the base plate I413 and the free end overlies the adjacent member. The free end of driven devices, single-phase induction motors are especially suitable and it is this type of motor 10 each of the'members is restrained ‘in movement both inwardly and outwardly by apin M8 work~ ing freely in a slot I50 in the underlying member. iWhen the ring structure is at rest or revolving atxlow speeds, the crescent shaped members are all. drawn inwardly‘ by the'springs Ml, as is indi cated by the showing of Fig. 11. When sufficient speed is attained by the shaft I 42, each of the members I132 flies outwardly under the influence of centrifugal force until stopped by the engage ment of the pins l £58 with the ends of the slots‘ I50. As the composite ring i it thus increases in radius, the outer edge impinges upon the upper lug l38of the contact carriage and pushes it upwardly in a uniform and gradual manner, and conversely, as 25 the composite ring M6 ‘decreases in radius with a decrease in speed, the inner edges of the mem bers I42 contact the lower lug H9 and push the carriage downwardly. Through the action of a pair of bowed springs I32, embraced between a portion I33 of the car riage and extensions I36 of the base member plate, the carriage is biased, in operation of the switch, toward either limit of its movement path so that a quick and positive snap actionof the 35 contacts is thereby effected. Thus, when the car riage is in the lower position illustrated, in which stationary contact members l2? are bridged by member I24, the action of these springs is to strongly hold it in that position and thereby 40 maintain the requisite contact pressure. LikeWise, when the carriage has been moved upwardly past the midpoint of its movement path, the springsurge it upwardly with a constantly in~ creasing force until it, reaches its upper position in which the bridging member B25 is biased against the stationary members S28, the bridg ing member I243 having by this movement been separated from the stationary members lE'I. The total range of movement of the carriage 50 and its actuating lugs E38 and i353 is made to ex ceed the variation in the radius of speed-respon sive ring H5, in order that the crescent shaped members I42 of this ring will not bear upon these lugs at the normal speed of the blower shaft M2, 55 the carriage being allowed to snap free thereof, during each switch actuation, under the in?uence of bowed springs I32, into its limiting position. The manner in which the centrifugal switch is connected in the energizing circuit of the heater is most clearly illustrated by the diagram of Fig. 13 from which it will be seen that a depression of ‘the treadle switch Bil ?rst energizes driving motor 2il'to start the blower is. Shortly before the blower attains normal speed, the centrifugal switch‘ actuates the bridging member I25 thereof upwardly to‘ complete an energizing circuit for the heater. 90. It will thus be noted that while an opening of. the control switch 30 deenergizes both the motor and the heater, upon a closure 70. thereof, heater energization can be eifected only while the blower is operating, a failure or discon tinuance of such operation immediately causing the centrifugal switch to disconnect the ‘heater from'the power source even though the motor 75'. may continue'to be energized. Effective protec (3 that I have illustrated as being incorporated in the improved hand drier of my invention. In order-that such a single phase motor may be started, it is necessary to provide it with ‘an auxiliary-winding, shown in the diagrammatic representation of‘Fig. 13 at I60, physically dis placed from the main winding, indicated at I62, which :main winding derives its energization directly from the supply conductors 75 through the control switch 80. In. order to- shiftjthe vphase position of the current ‘which is supplied to the. auxiliary-winding I69, it is necessary to insert in the supply circuit thereof some phase displacing device such as a capacitor I64, and it is preferable that this winding be maintained energized not only during the starting operation 25 but also during the normal full speed running op eration-of the motor 20. ' To increase the rapidity of starting of the motor, it is desirable insituations of this .kind to utilize a second or starting capacitor I 66 which 30 is connected in the auxiliary winding circuit for a short‘ period after- current is ?rst supplied to the motor, the function of this additional capac itor being to increase the current which circu lates through the auxiliary winding’ and there 35 by substantially raise the starting torque of the motor. To be most effective this increase in current is of such magnitude that damage from sustained overload would‘ result to the auxiliary winding I20 were the starting capacitor to be 40 permanently left in the energizing circuit there of. In the complete hand drier of my invention shown in Figs. 1 and 2, these capacitors I64 and I65 are shown as being mounted below the motor in the lower portion of the angle-iron frame. To effect a removal of this starting capacitor as soon’ as the motor has attained full speed, I utilize the secondset of contacts comprising bridging member I24 and stationary members I21 of the centrifugal switch, before described as be 50 ing actuated in accordance with the speed of the driven blower IE3. When the motor and blower are at rest, the bridging member I24 completes, as isshown by the diagram of‘ Fig. 13, an active connection of starting capacitor I66 in the cir cuit through which auxiliary winding I6!) of the motor is energized. 'As'soon as the motor and blo-wer'come up to speed, however, bridging mem ber I213 is, in the manner already explained, moved upwardly to thereby interrupt'the circuit of the starting capacitor to remove it from active service. ' Although I have'shown and described'a certain speci?c embodiment of my invention,'I am fully aware that many modi?cations thereof are pos sible. My invention, therefore, is not to be re stricted except insofar as is necessitated, by the prior art and by the scope of the appended claims. vI claim as my invention: 1. An electric drying device comprising, in com bination, ea draft-producing and air-heating mechanism, a structural frame for supporting said mechanism, and an exterior casing adapted to surround said frame and to form thereabove a pressure compartment intolwhich said mechanism 75 5 2,050,332 may discharge heated air, said compartment hav ing an opening through which said air may escape for direction against objects to be dried. 2. In an electrical drying device, the combina tion of a structural frame, an air-blower, a driv ?xture, said means comprising a ?exible metal strip through an opening in which the said ?xture extends, and grooves provided in the sides of said arcuate casing opening for slidably retaining the edges of said strip. " 5. In an electrical heating device comprising an ing motor therefor, and an air heater supported by said frame, an exterior casing adapted to ?t air-blower, a split-phase induction motor, having down over and be attached to said frame above which the upper portion of the casing forms a a pair of windings, for driving the blower, a source of power for the motor, a control switch, a circuit chamber, a partition between said chamber and the frame-supported mechanism therebeneath, for energizing one of said motor windings directly from the power source upon closure of the switch, said partition having an opening through which a phase-shifting element, and a circuit for ener the heated air is blown into the chamber, and said gizing the other motor winding through said ele ment upon closure of the switch, the combination of a centrifugal switch, responsive to the speed 15 of the blower, for interrupting said last-named circuit when the blower speed is, during a start ing operation, brought up to a value closely ap proaching normal. exterior casing having in the top portion thereof 15 an opening through which said air may escape for direction against objects to be dried. 3. In an electrical drying device comprising a casing in a portion of which is formed a pressure chamber provided with an air-discharge open 20 ing of arcuate contour, the combination of an air-outlet ?xture, a shaft, the ends of which pro trude through the sides of the casing, for adjust ably supporting the ?xture in said arcuate open ing, means for sealing against air escape the portions of said opening not occupied by the ?x ture, and handles attached to said shaft ends to enable an operator to change the position of the ?xture in the casing opening and thereby adjust the directions of air discharge. 30 4. In an electrical drying device comprising a casing in a portion of which is formed a pressure chamber provided with an air-discharge open ing of arcuate contour, the combination of an air outlet ?xture, a shaft, the ends of which pro trude through the sides of the casing, for adjust ably supporting the ?xture in said arcuate open ing, and means for sealing against air escape the portions of said opening not occupied by said 6. In an electrical drying device comprising a 20 heater, a blower for forcing air through said heater, a split-phase induction motor, having a pair of windings, for driving the blower, a source of power for the heater and motor, a control switch, a circuit for energizing one of said motor 25 windings directly from the power source upon closure of the switch, a phase-shifting element, a circuit for energizing the other motor winding through said element upon closure of the switch, and a circuit through which the heater may be energized, the combination of a centrifugal switch, which is responsive to the speed of the blower, adapted to interrupt the motor-energizing circuit last named when the blower speed is brought up to a value closely approaching normal and to, at 35 the same time, complete the said heater energizing circuit. R. H. JORDAN.