US2168836A - Thermostat - Google Patents

Description

l1g- 8, 1939. G. w. WHITEHURsT 2,168,836

THERMOS TAT 2 Sheets-Sheet l Filed Nov. 5, 1937 Aug. 8, 1939. G. w. wHlTEHuRsT THERIOS TAT Filed Nov. 5, 1937 2 Sheets-Sheet 2 Patented Aug. 8, 1939 UNITED STATES PATENT OFFICE 13 Claims.

This invention relates to a thermostat, and aims to provide, in a manner as'hereinafter set forth,

a device of the class referred to which is quickly responsive to sudden changes in temperature; easily and cheaply made; capable of operating in a satisfactory manner in any position which it may be set; of a size to occupy a small space; of sturdy construction; and adaptable for light and heavy work.

'I'he invention further aims to provide, in a manner as hereinafter set forth, a thermostat capable of being used for and in connection with that type of oil burner which does not require electrical operations for control.

The inventionfurther aims to provide, in a` manner as hereinafter set forth, a thermostat which is for use on light and heavy duty circuits; capable of being adjusted to close tolerance in temperature control; and so formed to make positive quick contact, as well as opening and closing with the same degree of snap.

To the above ends essentially and to others which may hereinafter appear, the invention conssts of the novel construction, combination and arrangement of parts as will be more specifically referred to and illustrated in the accompanying drawings wherein are shown embodiments of the invention, but it is to be understood that changes, variations and modifications may be resorted to 30 which fall within the scope of the invention as claimed. In the drawings Figure 1 is a side elevation of a thermostat in accordance with this invention,

Figure 2 is a top plan view thereof,

Figure 3 is a section on line 3 3, Figure 1,

Figure 4 is a section on line 4 4, Figure 1,

Figure 5 is a section on line 5 5, Figure 1 when the device is adjusted for quick snap action,

Figure 6 is a section on line 5 5, Figure 1 when the device is arranged for slow action,

Figure 7 is a section on line 1 1, Figure 1,

Figure 8 is a section on line 8 8, Figure 1,

Figure 9 is a fragmentary view in side elevation of a modified form,

Figure 10 is a side elevation of a modified form of thermostat, in accordance with this invention, disposed horizontally and with the housing for the elements of such thermostat illustrated in longitudinal section,

Figure 1l is a section on line II I I, Figure 10,

Figure l2 is a section on line I2 I2, Figure 10,

Figure 13 is a section on line I3 I3, Figure 10,

Figure 14 is a `section on line I4 I4, Figure 10,

(Cl. 20G-138) Figure 15 is a vertical sectional view of another modified form, and

Figure 16 is a top plan view of the structure shown in Figure 15.

Referring to Figures 1 to 8 of the drawings, the thermostat I illustrated thereby is adapted to be connected to a base 2 which may be of any suitable form, shown by way of example as consisting of a straplike member of angle form of the desired length and Width and of rectangular contour in transverse cross section. The said member includes a pair of end parts 3, 4 disposed in parallel planes and connected together by an inclined intermediate part 5. The part 3 is of less length than part 4 and is formed with a 1 screw-threaded opening 6 centrally thereof. Thel part 4 is provided with spaced aligned openings I for the passage of holdfast means, not shown for anchoring the base to a support.

The thermostat I includes a pair of thermostatic bars 8, 9 disposed in parallel spaced relation. The bar 9 is of greater length than the bar 8.y The bars have their elements I0 of greatest expansion arranged on and throughout their inner sides. The bars at the end portions II thereof have aligned openings I2, which also align with the opening 6 in the base 2. Arranged between the end portions II of the bars is a spacer block I3 formed with a. passage I4 having its ends aligning with the openings I2. The bars 8, 9, spacer I3 and base 2 are connected together by a holdfast means I5 extending through openings I2, passage I4 and having threaded engagement with the wall of opening I5` The bars 8, 9 are formed with aligned openings I6, I1 respectively. The opening I6 is of greater diameter than the opening II. Extending through the latter and anchored to bar 9, as at I8 is an adjusting screw I9, which also extends through, projects above and is of less diameter than the opening I6. Threadedly engaging with that portion of the screw I9 which projects above opening I6 is an adjusting nut 20. Surrounding the screw I9 and interposed between bar 8 and nut 20 is a coiled tensioning spring 2|. The bar 8 in close proximity to its ,end 22 is provided with a pair of spaced parallel positioning pins 23 of a length to extend above and to depend below bar 8. The latter is formed with an opening 24 interposed between the opening I 6 and the end 22 thereof. The purpose of the opening 24 will be referred to.

The bar 9 in proximity to its end 25 is formed with a screw-threaded opening 26 and inwardly adjacent the latterwith an opening 21 of greater ferred to.

diameter than the opening 26. Positioned on the inner side of bar 9 and projecting beyond the end 25 of the latter is a rectangular block 28 of insulation provided with openings 29, 30 and 3|. The openings 30, 3| align with the openings 26, 21 respectively of the bar 9. The block 28 is anchored to the bar 9 by a tie bolt 32 threadedly engaging with the walls of the openings 26 and 30. Extendin g through the opening 29, as well as threadably engaging with they block 28 is a binding post 33 provided at its upper end with a contact 34. Threadably engaging with the wall of the opening 3|, extending in the opening 21 and projecting above the block 28 is a travel controlling screw 35 for a circuit opening and closing member to be referred to. The lower end of the screw 35 is spaced from the wall of opening 21. The screw 35 is of greater length than the bolt 32 and has its head 36 spaced above the block 28.

The thermostat l includes a combined snapping, snap regulating and circuit opening and closing mechanism generally indicated at 31 and which is arranged above and below the bar 8, as well as projecting from the latter to over the contact 34. The mechanism 31 is to normally engage the contact 34. The mechanism 31 includes a pair of superposed compression levers 38, 39, the former being arranged above and the latter below the bar' 8 and positioned at one end between the pins 23 is a pair of oppositely disposed shifters 40, 4| of like form and each consisting of a horizontally disposed part 42 and an outwardly inclin'ed part 43. The shifters are constructed of light spring metal and are of concavoconvex contour in transverse cross section. The parts 42 ofthe shifters are arranged between the pins 23. The part 42 of shifter 40 is positioned on the outer side of bar 8 below the lever 38. The part 42 of the shifter 4| is positioned against the inner side of the bar 8 and above the lever 39. The parts 42 of the shifters are anchored -to the bar 8 by a securing pin 44 which extendsv 'above part 42 of shifter 49 and depends below part 42 of shifter 4|. The pin 44 is upset at each end to provide the heads 45, 46 for a purpose to be re- The pin 44 extends through the levers 38, 39, which are provided intermediate their ends with openings 41, 48 for the passage of the pin 44. The heads 45, 46 provide Vfulcrums for the levers 38, 39 respectively. The lever 38 is formed with a screw-threaded opening 49 which aligns with the opening 24. Threadably engaging with the wall of the opening 49, extending through opening 24 and seated on lever 39 is an adjustable snap regulating screw 50.

The mechanism 31 includes a .coupling block 5| of insulation material provided with a transverse groove 52 opening at its sides and at one end. The block 5| tapers in opposite directions to provide points 53,-and extends between and has its points 53 bear against the inner sides of the parts 43 of the shifters in proximity to the free ends of such parts. The parts 43 of the shifters are connected to the block 5| by the securing pins 54. The block 5| is arranged above and spaced from the block 28. Extending into the groove 52 and anchored to the block 5| by the holdfast means 55 is a circuit opening and closing member 56 of a length to extend over contact 34. The

. member 56 is provided withan opening 51 through which extends the shank of the screw 35. The

opening 51 is of greater diameter than saidv the latter is moved from circuit closing position. The member 56 is provided on its inner face with a contact 58-which coacts with the contact 34 for the purpose of closing the circuit when the contacts are in engagement. A binding post 59 is connected to member 56 and has its inner end provided with the contact 58.

With reference to the modied form shown in Figure 9, and indicated at 60, it is of the same construction as the form shown in Figure 1 with this exception that the thermostatic bars 6|, 62 have their elements 63 of greatest expansion arranged on the outer sides of the bars. Otherwise than that as stated, the form shown in Figure 9 will be the same as that shown in Figure 1.

The thermostat is of a form to break the contact when a predetermined maximum degree of temperature acts thereon. 'Ihe thermostat 60 is of a type to break the contact when a predetermined minimum degree of temperature acts thereon. The function referred to with respect to thermostat is due to the manner in which the elements of -the greatest expansion of the thermostatic bars 8, 9 are arranged on said bars. The function referred to in connection with thermostat 60 is due tothe manner in which the elements of least expansion of the bars 6|, 62 are arranged on said bars. With respect to the thermostat the elements I0 of the thermostatic bars 8, 9 when maximum temperature is reached will cause the non-anchored ends of the bars to move apart from each other. With respect to the thermostat 60 the elements 64 of least expansion when minimum temperature is reached will cause the non-anchored ends of the bars to move apa-rt from each other. When the non-anchored ends of the thermostatic bars move away from each other, the contacts 34, 58 are moved out of contacting relation.

The adjusting screw I9, nut 20 and spring 2| are for the purpose of adjusting or placing the thermostatic bars 8, 9 in their correct or desired position to govern a desired or certain temperature setting so that the contacts 34, 58 are opened and closed at the desired temperature.

The parts 42, 43 respectively of the shifters 40, 4| are termed Shanks and heads respectively. The shanks are held stationary against opposite sides of the bar 8.

shifters at the point of mergence of said Shanks with said heads. The heads extend from bar 8 and are inclined outwardly in opposite directions. The heads are capable of bending or snapping in unison in like directions with respect to the shanks. The bending or snapping movement of the heads is an oscillatory one and such movement provides for a snap opening or closing movement relative to the contacts 34, 58. This movement in relation to the contacts is regulated in a manner to be referred to. v

The screw 5|) of the mechanism 31 is for the purpose of applying varying pressure on one end of the lever 39. The purpose of this pressure variation is to provide for the ends A of the levers 38, 39 to move out relative to the shanks of the shifters to allow the full curve of the heads of the shifters to exist, and when resistance to the compression effort on the part of the levers is overcome, the heads give away with a quick snap or `suddent movement. The snap of the heads is controlled by the extent of reducing the curvature of the heads. The greatest snap is had when the curvature of the shifters is as shown in Figure 5.

The levers 38, 39 act at one -l end thereof for compressing the body of the The movement of the snap gradually decreases until the shifters assume a flatcross section as shown in Figure 6. The shifters are mounted in a manner to provide a counterbalance in their resistance to each other and produce a very acute dead center or balance of effort and cannot be positioned on their dead centers. When this dead center point is reached very little effort is required to alternate the movement of the contacts to or from each other quickly and firmly, and the degree of quickness and firmness of the contact points movement can be varied by compressing the shifters until they assume a fiat position such as shown in Figure 6 and then the heads possess no snapping action at all.

With reference to Figure 1, the thermostat is illustrated in a near neutral position with contacts 34, 58 spaced from each other. 'I'he heat will cause the bars 8, 9 to separate at their free ends whereby member 56 will be shifted to bear against the head 36 of screw 35 and under such conditions the alternate movement of such member will be arrested and as the flexing point of the mechanism is at A the effort of the bars 8, 9 vacts to break the back of shifter 40 at B and allows shifter 4| at C to straighten up and thus provides for the shifters 40, 4| to snap the contacts 34, 58 4into engagement. The reverse order of operation opens the contacts.

The arrangement of the parts of the thermostat I provides for a sturdy construction andyet permits a very delicate and close setting of telnperature control. The statement applies to the modified form shown in Figure 9.

With reference to the modified form of thermostat 65 shown in Figures 10 to 14 both inclusive, it includes a cylinder or housing 66 open at one end and closed at its other endf by a cap 61. Mounted on and extended from the open end of the housing 66 is a peripherally threaded mounting nipple 68. The elements 66, 61 and 68 may be formed of any suitable material. The thermostat 65 is to be horizontally disposed and includes a depending means to be referred to for controlling a valve mechanism or other suitable device, more particularly an oil level controlling and fuel regulating mechanism for oil burners.

Arranged within the housing 66 abutting against the cap 61 and seating on the inner face ol` the nipple 68 is a base 68 of strap-like form of the desired thickness and Width. The base 69 is of angle contour and includes an upstanding leg 1|] and a horizontally disposed leg 1| having its end terminal portion 12 offset outwardly with respect to its remaining portion. The leg 10 snugly abuts against the inner face of the cap 61. A part of the leg 1| snugly abuts against the inner face of the bottom of the housing 66 and a part of the offset terminal portion' of leg 1| snugly abuts against the inner face of the bottom of the nipple 68. The terminal portion 12 o f the leg 1| is anchored to the nipple v|58 by the holdfast means 13.

The thermostat 65 includes a pair of thermostatic bars 14, 15 disposed at parallel spaced relation and with the bar 14 projected beyond one end of the bar 15. The element of each of the bars of greater expansion is indicated at 16 and l it is arranged on the inner side of each bar. The bars 14, 15 abut the leg 10 of the base 69. Interposed between said bars is a spacer block 11 of any suitable material which abuts the leg 10 of base 69. Interposed between the bar 15 and the leg 1| of the base 69 as well as abutting leg 10 is a spacer block 18 of any suitable material.

The bar 14, block 11, bar 15, block 18 and leg 1| have aligned openings 19, 80, 8|, 82 and 83 respectively. The wall of the opening in the leg 1| is screw-threaded. Extending through the aforesaid aligned openings and threadably engaging with the wall of the opening is a headed tie bolt 84 functioning to connect the thermostatic bars, the spacer block and the base 69 together.

Anchored to the bar 15 and extending upwardly through an opening 85 in the bar 14 is a positioning pin 86 of a diameter less than the diameter of the opening 85. Anchored at its lower end in the bar 16 in proximity to the free end of the latter is a vertically disposed adjusting screw 81 which extends upwardly through an opening 88 in the bar 14. Threadedly engaging with the upper portion of the screw 81 is an adjusting nut 89 and interposed between the latter and the bar 14, and surrounding the screw 81 is a coil tensioning spring 9|).

The thermostat 65 includes a shifting arm 9| for the mechanism which is to be controlled by the thermostat. The arm 9| has its body formed of like material from which the bars 14, 15 are formed. The arm 9| projects outwardly from the nipple 68 and is provided at its inner end with a notch 93, at its outer end with an opening 94 and intermediate its ends with an opening 95. The pin 86 extends through the notch 93 and is of less diameter than the width of such notch. The screw 81 extends through the opening 95 and is of less diameter than the diameter of such opening. The arm 9| fulcrums on the free end of the bar 15.

The element 92 is shown by way of example as a lift rod 96 having a peripherally threaded upper portion carrying an adjusting nut 91 for abutting the outer end of arm 9|. As the elements of greatest expansion of the bars 14,'15 face each other, the heat, at and above maximum temperature causes the outer or free ends of the bars 14, 15 to separate o1' travel further apart. The screw 81, nut 89 and spring 90 are employed for adjusting the bars 14, 15 to provide for the thermostat to operate at any desired temperature setting. The arm 9| is also a thermostatic bar, A

but has the element thereof of greatest expansion on its upper side. The arm 9| in proportion to the length of the part inserted between the bars 14, 15, from pin 86 to screw 88 and from the screw 81 to its outer end or nut 91 determines the amount of travel between the free ends of the bars 14, 15 and it also magnies the travel at the service ends of the thermostatic bars or the element 92. threaded upper terminal portion of the bar 96 provides for the adjusting of the element 92 relative to arm 9| thereby providing an additional adjustment to the device which is to be controlled from element 92.

With respect to the modified form of thermostat 98 shown in Figures 15 and 16, it is of the same construction as the thermostat with this exception that it is so disposed to provide for the verticalv moving of the actuating or multiplying movement arm 99 for the element '|00 which it lifts and lowers. vThe arm` 99. is formed of the same material as'the arm 9|, but it is of angle form and includes an upstanding branch IUI disposed at an inclination to the vertical'and a horizontally disposed branch |02 extending outwardly at right angles to the upper end of the branch IUI. The .element |00 is carried by the branch |82. The element |00 is of the same form as The nut 91 in connection with the Cil In Figures 15 and 16 the housing, which is vertically disposed is indicated at |03, the closure cap for one end of the housing at |04, the base |05, the thermostatic bars at |06, |01, the spacer blocks |08, |09, the adjusting means for the bars |06, |01 at ||0 and the nipple at ill. The base |05 is disposed vertically, but it is of the same form as the base 69. As aforesaid, the construction of the thermostat 98 is the same as that of the thermostat; 65, with the exceptions that the thermostat 98 is vertically disposed and the arm 99 which corresponds to the arm 9| is of angle contour.

With respect to the thermostat 65, when the bars 1d, l5 thereof move apart at their free ends it allows for the inner end ofthe arm 9| where it is pressed against the inner face of bar 'lll to move up and as arm 9| fulcrums on bar l5, that arm 9| at such point rocks and permits a magnified downward movement to the outer end of arm 9| and as the latter is of thermostatic bar-like form, it also adds its movement to the nut 97.

It is obvious that by placing the least expansive elements of the thermostatic bars 14, 'l5 face to face, and reversing the position of the greatest expansive element of the arm 9|, a reverse movement of the nut 91 will occur on heat and by this arrangement control may be had for lift on cold,

l or for lift on heat.

What I claim is:

1. In a thermostat, a pair of thermostatic bars, means for anchoring one end of the bars together and for maintaining them in parallel spaced relation, one of said bars being of greater length than and extended beyond the other end of the-other bar, that bar of greatest length being provided with a contact positioned beyond the bar of shortest length, and a combined snapping, snap regulating and circuit opening and closing mechanism carried by the bar of shortest length for coaction with said contact and having its operation controlled by the thermostatic movements of said bars.

2. The invention as set forth in claim 1 having said mechanism provided with controllable oppositely disposed bodily depressible shifters of concavo-convexo contour in transverse cross section.

3. The invention as set forth in claim 1 having said mechanism provided with controllable oppositely disposed bodily depressible Shifters of like form and of concavo-convexo contour in transverse cross section, each of said shifters including a shank and a head, said heads moving in like direction with respect to said shanks on the operation of said mechanism.

4. The invention as set forth in claim 1 having said mechanism provided with fulcrumed pressure applying levers and oppositely disposed shifters of like form and of concavo-convexo contour in transverse cross section having their movement controlled by said levers.

5. In a thermostat, a pair of thermostatic bars, means for anchoring one end of said bars together and for maintaining the bars in parallel said mechanism provided with controllable oppositely disposed bodily depressible resilient shifters of concavo-convexo contour in transverse cross section, said shifters being connected with said member.

'1. In a thermostat, a pair of spaced thermostatic bars, means for anchoring one end of the bars together and for maintaining. the bars in spaced relation, one'of said bars being of greater length than and extended beyond the other end of the other bar, said bar of greatest length being provided with a contact outwardly adjacent the bar of shortest length, and a combined snapping, snap regulating and circuit opening and closing mechanism carried by the ba'r of shortest length for coaction with said contact and including resilient pressure controlled Shifters, said mechanism having its operation controlled by the thermostatic movements of said bars.

8. In a thermostat, a pain of thermostatic bars,

means for anchoring one end of the bars together and for maintaining the bars in parallel spaced relation, a resilient setting structure for said bars, said structure being anchored to one of the bars, extending through the other bar and bearing on the latter, a positioning pin anchored to one of said bars and extending through the other, and a multiplying arm having its body corresponding to the body of either of said bars, said multi; plying arm extending between said bars and projecting from the other ends of the bars, said arm at its inner end bearing against said pin, mounted intermediate its ends on an element of said structure and having its outer end provided with an opening for the reception of a controlling eleu ment, said arm bearing at its inner vend against the inner face of one of said bars and bearing intermediate its ends upon the other of said bars.

9.Y In a thermostat, a pair of thermostatic bars, means for anchoring one end of the bars together and for maintaining the bars in parallel spaced relation, a resilient setting structure for said bars, said structure being anchored to one of the bars, extending through the other bar and bearing on the latter, a positioning pin anchored to one of said bars and extending through the other, and a multiplying arm having its body corresponding to the body of either of said bars, said multiplying arm extending between said bars and projecting from the other ends of the bars, said arm at its inner end bearing against said pin, mounted intermediate its ends on an element of said structure and having its outer end provided with an opening for the reception of a controlling element, said arm bearing at its inner end against the inner face of one of said bars and bearing intermediate its ends upon the other of said bars, said arm being formed of a pair of branches disposed in angular relation.

10. In 'a thermostat, a pair of thermostatic bars, means for anchoring one end of the bars together and for maintaining the bars in parallel spaced relation, a positioning pin anchored to one of said bars and extending through an opening in the other of said bars, said pin being of less diameter than said opening, a resilient setting structure for said bars, said structure including an element anchored at one end to one of the said bars said bars and with-such openingibeing of greater diameter than said element, and a multiplying arm of thermostatic characteristics extending between and projecting from said bars for operating a. controlling element, said arm having its inner end bearing against the inner face of one of said andextending'- through an opening in the other of bars and at a point adjacent its inner end bearing against the inner face of the other of said bars, said arm having its inner end bearing against said pin formed with an opening for the passage of said element and with the opening being of greater diameterthan the diameter of said element.

.11. In a thermostat, a pair of thermostatic bars, meansy for anchoring one end of the bars tomaintaining `them in parallel ing means for regulating the snapping movement of said structure.

l2. In a thermostat, a pair of thermostatic bars, means for anchoring one end of the bars together and formaintaining them in parallel spaced relation, one of said bars being of greater length than and extended beyond the other end of the r bar, that bar of greatest length being provided With a contact positioned beyond the bar of shortest length, a Contact movement of the latter.

GEORGE W. WHI'I'EHURST.

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