US2124984A - Electric iron - Google Patents

Description

July 26, 1938. J. MCCULLOUGH 2,124,934

ELECTRIC VIRCJN Filed March 28, Y 1936 Zn yen for or is surrounded a s suriace. Frequently the tioerrnostatic member aected more readily oy tile tem nerature oi and surrounding tlie heating element jratlier than by the temperature of the portion of the iron applied to the article being ironed.

Obviously such arrangements do not make for accurate or eicient operation or the thermostat, and one object of the present invention is to correlate an ironing surface, the thermostatic control, the heating element, and the parts actuated thereby so that each will possess a' high degree of eiiciency from the standpoint of operation, simplicity of construction, and length of life, etc.

l Another object of the invention is to simplify the manually operated device for varying the temperature of the iron and, incidentally, to give the iron a neat, attractive appearance notwithstanding the mounting of the manual control in the handle and the necessity of connecting such a control to mechanism in the' ironv casing.

Another object of the invention is to simplify the assembly of the heating element with.` the iron sole plate and at the same time to provide eiicient distribution of heat from the element to the sole plate.

These and other detail objects which wl be apparent from the following description are obtained from the structure illustrated in the accompanying drawing, in which- Figure l is a vertical longitudinal section through an iron of the type described, a portion of the structure being shown in elevation.

Figure 2 is a horizontal section taken substantially on the line 2--2 of Figure 1.

Figures 3 and 4 are vertical transverse secv tions taken on the lines 3-3 and vali-Jl, respectively, of Figure l, Figure 3 showing the parts in a diilerent position than indicated in Figure 2.

. static member meer;

substantie tiofougiiout i the fnd reierably is made in length o two sections spaced across the iron. A.

relatively liglit metal sheet extends over heating element il witli its edges oiset downwardly, as at G, to contact with the sole plate. Preferably sheet has an intermediate depression l also contacting with the sole plate in the space between the sections of grid al.

Current is brought to the terminals 8 and e by any usual plug. Conduct le leads from terminal 8 to one end of the heating grid. Conduit il leads from the other end of the grid to the binding'post il. Switch blades i3-and l@ of spring material are insulated from each other at their right hand ends and have contact buttons l5 and l, repsectively, on their left hand ends. Blade i3 is connected to binding post i2 and blade lil has a connection il to terminal d. Normally the spring action of blades i3 and lll is to thrust eachof these blades' in an anticloclewise direction as indicated by the arrow A.

Thermostatic member 3 comprises a loi-metallic helix o familiar type although not previously used in electric irons, so far as I am in formed. Each end oi member 3 is provided with` a longitudinal slot, and a. pin ld has the inner face of its slotted head seated against the edge of the sole plate surrounding the outer end of noie 2 with the inner end of the nin provided vwith a lip l., fitting into the corresponding slot in member A finger is has its lower end tted into the slot in the right hand end oi member 3 and extends upwardly through the top of the sole plate through sheet 5 and into Contact with an insulation roller 2li carried on the outer end of blade i3. A screw 2l (Figure 4) is threaded into the edge o sole plate l with its head overlapping the head o pin lil whereby pin lil and the adjacent end of the thermomay be anchored Vto the soie plate.

dit

As member t is heated, its bi-metallic construction causes it to twist so that its opposite ends rotate about its axis in opposite directions. With the right hand end being held against rotation, particularly in an anti-clockwise direction as indicated at X in rFigure t, the left hand end, carrying inger i9, tends to -rotate in a clockwise direction as indicated by they arrow .B in Figure 3. Such rotation oi ringer i9 will move blade i3, against its spring tendency, to separate contacts i5 and l as indicated in Figures 3 and 5.

Upon cooling, the thermostat tends tov return Y to its original position. Switch blade [it is recessed at itc to provide clearance ior inger t@ so that stresses in the thermostat may be fully relieved. By loosening screw 2i and rotating pin is, thermostatic member 3 may be adjusted axially to vary the temperature at which it opens the switch or permits the switch. to close.

When ringer i@ and blade it are engaged, the reaction of the pressure between them will thrust member 3 against the side oi hole 2, creating sumcient friction to retard free twisting movement of member 3 and resulting in a lag between alternate movements of the thermostatic member and its nnger. This avoids dut-- tering of the switch contacts and rapid opening and closing of the circuit, which is objection.e able because of resulting annoyance in reception of radios which may be on the same house circuit.

A sheet metal casing 22 is applied to the soie plate and encloses the heating element, switch l "minals d. iEhe front 'portion or bow of the handle curves downwardly in an arc se of acircle. A portion of this part of the handle isl hollow to form a chamber which receives a rigid segmental bar 2d slidable in the handle fromv the position shown in full lines in Figure i to the position shown in dot and dash lines. S indicates a spring frictionally engaging bar 2e to resist its accidental movement.

A slot 2l leads from the hollow interior of the handle and a boss 23 on the upper end of bar 2d projects through slot 2 so as to be readily engaged by the thumb of the user of the iron. The lower end of bar 2t forms a horizontally wedge-like structure 2t, one edge of which slides along a bearing t@ formed on casing support di. The other edge of wedge 2t engages an insulan tion roller t2 having a vertical axis and mounted on an extension 33 on switch loladeA ld.

Obviously movement of boss 28 in the direction of the arrow SC moves wedge 29 in the op posite direction and thrusts blade id in a direction opposite to arrow A, thereby' moving blade .it (if buttons l5 and it are in contact) away A handle arrasar Preferably a tail 3d projects from boss 2t and closes the bottom of slot 2ll as the boss is moved forwardly.

The rear of casing 22 extends beyond the rear end of sole plate i and terminates in a` heel 35 which meets a nish strip it extending upwardly from the bottom of sole plate l to the end of heel 35. A wire bail 3l loosely mounted on plate t between heel 35 and strip 36 cooperates with guard 2d for supporting the iron when 'it is stood on end temporarily' while the material to be iron'ed is being adjusted. in this position elements 35 and 36 are spaced from the ironing board or table.

Although strip t aords a neat nish for the lower rear portion of the iron, the notch or opening 3d therein provides access to screw 2l and plug iii whereby the latter may be adjusted to set the thermostat operation as desired.

The construction described is simple and free of a multiplicity o jointed members particularly in the connection between the switch adjustment and the control boss 2t. The adjustment device in the present iron comprises a single rigid bar mounted on the handle and therefore easily assembled with the casing and switch mechanism.

Obviously theparticular arrangement of the switch parts and the details of the thermostat and its nger, the adjusting switchrand the elements engaged thereby, are not essential to all features of the invention and these and other details may be varied without departing from the spirit oi the invention and the exclusive use of such modications as come within the scope of the claims is contemplated.

I claim:

l. In an electric smoothing iron, a sole plate, a light metal sheet overlying said sole plate and cooperating with the top face thereof to form a shallow housing, a heating element enclosed in' said housing, and a thermostatic member for controlling current to said element located beheath said top face of said sole plate and between said element and the smoothing surface of said sole plate. I

2L In an electric smoothing iron, a sole plate, a web-like heating element overlying said sole plate, a thin sheet metal cover for said element cooperating with the top face of said sole plate to form a housing for said element, a switch above said cover, a thermostatic member enclosed in said sole plate below said cover, and a switch actuating element extending through said cover and the top part of said sole plate and operatively engaged by said therrnostatic member.

3. In an electric smoothing iron, a sole plate having along narrow hole leading inwardly horizontally from one edge' thereof and located below the top face of said sole plate, a heating element overlying said sole plate, an electric circuit therefor including a switch having a nger projecting downwardly into said hole, an elongated thermostatic member inserted in said hole through the end thereof in said edge until enclosed in said hole and comprising a bi-metallic helix with one end anchored to said sole plate adjacent to said edge and the other end operatively connected to said finger.

4. In an electric smoothing iron, a sole plate having a hole leading inwardly from one edge thereof, a heating element overlying said sole plate, an electric circuit therefor including a switch, an elongated thermostatlc member inserted in said hole and lying adjacent to one side thereof, said member .comprising a iai-metallic helix 'with one end anchored to lsaid `sole plate and the other end operatively connected to said switch, the parts of said helix being so disposed that heat actuated rotary movement of said member moves a part of said switch and the reaction on said member thrusts it against the side of said hole to irictlonally retard the rotary movement of said member.

5. In an electric smoothing iron, a sole plate, a heating element applied thereto, an electric circuit for said element having a switch with an adjustable contact adjacent to said sole plate, a casing enclosing said switch, a handle having an arcuate bow portion mounted on said casing, an iniiexible member on said` handle mounted to slide longitudinally thereof and provided with an arcuate extension housed within said handle portion and projecting into said casing and operatively connected to said contact.

6. In an electric smoothing iron, a sole plate of the usual contour, a heating element overlying said sole plate, a thermostatic member enclosed in .said sole plate, a iinger connecter to said member and projecting upwardly from said sole plate near the center thereof, a switch for con-l trolling current to said element and including a movable part engaged by said nger, a casing mounted on said sole plate and housing said element, finger and switch, a handle having a bow curving from one end downwardly and inwardly to said casing, and an arcuate arm slidably mounted in said bow with its lower end terminating adjacent to said finger. and part for regu lating said switch and with its upper end terminating in a manually engageable device movable along the front portion of said handle.

7. In an electric smoothing iron, a sole plate, a heating element, a thermostatic member for controlling the supply of current to said heating element, a handle provided with a hollow portion, there being a slot in the tace oi.' said handle leading to said hollow portion, an inflexible bar slidable in said hollow portion and having a boss projecting through said slot for manual manipulation of said bar, said bar in-v cluding a part closing said slot in front oi' and at the rear of said boss, and means actuated by' said bar to vary the operation of said thermo static member. 1

3. In an electric smoothing iron, a sole plate having a holeleading inwardlyirom one edge thereof, an electric heating element, a circuit therefor, a thermostatic member for controlling said sole plate edge, said pin having a lip entered in said slot.

9. In an electric smoothing iron, ascle plate having a hole leading inwardly irons. one edge thereof, an electric heating' element, a circuit therefor, a thermostatic member inserted in said hole and comprising a lai-metallic helix, with a transverse slot in each of its ends, means for adjustably holding the outer end oi said member against rotation comprising a part having a lip in said slot and a screw seated against said edge and clamping said part, and means ior controlling said circuit including a finger tting in the slot at the other end ci said member and movable by axial rotation of said other end of said helix.

l0. In an electric smoothing iron, a sole plate, a, bi-metalllc thermostatic member enclosed between the top and bottom of said sole plate, an electric resistance heating element for said sole plate, a circuit therefor, and means actuated by deformation of said thermostatic member' irrespective of the expansion and contraction of the surrounding sole plate' for controlling said circuit.

ll. In an electric smoothing iron, a sole plate, a thermostatic member enclosed between the top and bottom of said sole plate and comprising a bi-metallic helix, an electric resistance heating element, a circuit thereof, and means actuated by heating and cooling of said, helix for respectively opening and closing said circuit to control the supply of current to Asaid element irrespective of the expansion and contraction of the surrounding sole plate.

l2. in an electric smoothing iron, a sole plate, an electric resistance heating element associated therewith, a thermcstatically operated switch for controlling the'ele'ctric circuit o! said element and including a member adjustable to diierent positions to open and close said circuit at different temperatures, a handle' spaced substantially above asid sole plate element and switch, and a manually movable inflexible device extending from said member to the upper portion of said handle, every part of said device being movable in the arc oi an upright circle.

13. In an electric smoothing iron, a sole plate, means for heating said sole plate, a handle i'or manipulating the iron, said handle including a hand hold spaced above said sole plate and an arcuate portion between said hand hold and the sole pla a manually adjustable inexible device adjacent said hand hold, and an arcuate member operatively connecting said element to said means and movable in said arcuate portion along the line of its arc l PAUL J. MCCULIDUGH.

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