US3156802A - Thermal time delay relay with relatively flexible control member - Google Patents

Description

Nov. 10, 1964 A. A. DE FALCO THERMAL TIME DELAY RELAY WITH RELATIVELY FLEXIBLE CONTROL MEMBER Filed April 24, 1957 FIG.4

ANGELO DE FA LCO INVENTOR.

United States Patent 3,155,562 THERMAL TIME DELAY RELAY WITH RELA- TIVELY FLEXIBLE CONTROL ll/IEMBER Angelo A. De Falco, lrvington, N.I., assignor to Falcon Electronics Corp., Harrison, NJ. a corporation of New Jersey Filed Apr. 24, 1957, Ser. No. 654,9tl3

14 Claims. (Cl. 200-422) This invention relates generally to a control device in an electrical circuit and more particularly to a hermetically sealed thermally actuated time delay device or relay for use in an electrical circuit, as a continuationin-part of the copending application Ser. No. 542,923, filed October 26, 1955, now Patent 2,817,731 issued December 24, 1957.

In the copending application Serial No. 542,923 filed October 26, 1955, and now Patent 2,817,731, a hermetically sealed thermally actuated time delay device was disclosed which included a thermally responsive primary actuating member adapted to expand and contract responsive to variations in current in the electrical circuit to which it was connected and a secondary control member of fixed length each mounted at one respective end thereof to a point of reference in said device in spaced relation to each other and joined at their other ends remote from the point of reference to each other and an adjustable time delay setting means for exerting suflicient force on the coacting members to simultaneously place both members under compression and to place the secondary control member of fixed length under a predetermined tension whereby a switch element including an arm connected at one end to an intermediate point on said secondary control member and having a contact at the other end to enact with the stationary contact will be actuated on operation of the time delay device to open and close in accordance with the longitudinal expansion of the thermally responsive primary actuating member for the time delay corresponding to the predetermined tension setting of the secondary control member.

It has been found, however, that the necessity for placing the primary and secondary members under the compression and tension relationships was not necessary if the secondary control member was suiliciently flexible and was contructed such that it had a relatively short leg and a relatively long leg with a bend or angle therebetween forming a moment origin so that with the expansion of the control member actuation of the movable arm connected to the control member will occur.

Accordingly, it is an object of the present invention to provide a highly simplified thermally actuated time delay device which may be made in relatively small sizes without sacrificing the accuracy of its operation.

Further objects and advantages of the invention will become evident from the following description with reference to the accompanying drawings in which:

FIGURE 1 is a vertical section showing one form of the present invention.

FIGURE 2 is an end view of the invention shown in FIGURE 1.

FIGURE 3 is a cross section taken on line 3--3 of FIGURE 1.

FIGURE 4 is a cross section through the actuating member taken on line 4-4 of FIGURE 1.

FIGURE 5 shows diagrammatically the actuating member and the control member in equilibrium.

FIGURE 6 shows diagrammatically the same elements shown in FIGURE 5 when the actuating member expands.

FIGURE 7 is a vertical section shown a modified form of the present invention.

FIGURE 8 is a vertical section showing a further modified form of the present invention.

FIGURE 9 is a side view of the control member shown in FIGURE 8.

Referring to the drawings, FIGURES l and 2 show the time delay control device generally designated A having a header or support base 1 of a non-conducting or insulating material. The base 1 is provided with a plurality of circumferentially spaced contact prongs 2a, 2b, 2c, 2d, 22, 2 and 2g and has an annular flange 3 about the outer periphery for mounting a container 4 as by welding or any other suitable means to provide an airtight joint. The container or case 4 is hermetically sealed, the air in the container having been withdrawn prior to the sealing process in a manner well known in the present art and not more fully discussed herein as it does not form part of the present invention.

Mounted in the container is a primary or actuating member generally designated 6 and a secondary or control member 7.

The actuating member 6 includes a shell or expander element 3 which is struck from an integral piece of metal so that it provides a T-shaped bracket 9 at one end to connect the actuating member 6 to the prongs 2a and 2d in the base or header 1 as is clearly shown in FIGURES 1 and 3 of the drawings.

FIGURES 1 and 4 show that the expander element 8 houses or encloses in compact and closely sandwiched form a heater comprising the conventional mica element lti with a coil of electric conducting wire 11 wound thereabout. Insulation elements 12 on opposite sides of the heater are of mica and transverse members 13 are filler material enclosed by expander element 8.

The electric conducting wire 11 is connected to the prongs 2b and 20 respectively which communicate with the circuit in which the relay is connected. The circuit delivers a variable current to the electric conducting wire 11 and thereby varies the amount of heat delivered by the heating element to the expander element 8 of the actuating member.

The expander or shell 8, the transverse element 13 and the control member or arm 7 will be of a material such as stainless steel or the like type alloy having a high coeflicient of expansion. The relative mass to surface area of the expander element or shell 6 being regulated by the added thickness of these elements 13 and the insulation therebetween in order to obtain the desired degree of expansion and contraction with variation in the heat developed by the current delivered to the coil of the Wire in the heater.

The end of the expander element or shell 8 remote from the end fixed to a point of reference or base 1 is free to expand and contract relative to the base and is provided with a bracket 14 for connecting the free end of the expander element 8 of the actuating member 6 to the control member '7. The other end of the control member 7 is connected as by a strip or element 15 to the prongs 2 and 2g in the base 1 which as shown in FIGURES 1 and 2 are a spaced distance from the prongs 2a and 2d to which the corresponding end of the actuating member 6 is connected.

CONTROL MEMBER OR ARM The control member or arm 7 is flexible. It has a predetermined fixed length which varies for the purpose of the present invention only with changes in temperature in the member itself and in operational effect. The ratio of the length of control member or arm 7 to that of the expander element 8 plus the degree of flexibility of the control member 7 are important factors in determining the range of the time delay settings for a particular relay as is more fully set forth hereinafter.

Mounted to the side of the control member or arm 7 facing the actuating member 6 is a movable arm 16 having a contact 17 at the end remote from the point of connection to the control member '7. The movable control engages a stationary contact 18 which is fixedly connected to prong 2e in the base member 1. Since the control arm is connected to the prongs 2 and 2g a circuit may be controlled wherein the movable contact 17 is brought into and out of engagement with the stationary contact 18 in accordance with the time delay periods set. In this form of the invention, this is accomplished by adjusting the angle 19 so that the contact 16 may be spaced closer or further from the stationary contact 18 as the time delay setting requires.

Assuming the same amount of current is applied to the heater circuit of any actuating member, the length or time characteristic of the time delay setting will be a function primarily of the speed of movement of the actuating member. The speed of movement in turn is determined by the amount of material embodied in the actuating member. Thus, where the length of the actuating member remains constant, for a given amount of heat, it will expand to a certain length. To change the length of time that it takes to reach its ultimate length for a given heat application material may be added or subtracted from the total mass of the actuating member, more material lengthening the time delay and less material shortening the time delay.

If the angle 19 is so adjusted that the contact 16 will engage the contact 18 when the actuating member has reached approximately of its full length, the relay will operate even though lower voltage is applied to the heater.

The control member or arm 7 is shown in FIGURE 1 having a substantially elongated flat portion 24 and angled or bent portion 21 and a transverse portion 22 forming a single continuous element between the bracket 14 and the strip or element 15. The bend or angle section 21 is disposed closer to the point where the control member or arm 7 connects to the bracket 14 on the shell 8. Thus the transverse portion 22 is short and hence relatively stiff compared to the long relatively flexible flat portion 241.

This construction permits the actuating member 6 and the control member 7 to operate from a condition of equilibrium. When the actuating member 6 expands it stretches the stiff transverse portion 22 away from the fiat flexible portion 20. However, due to the fact that there exists a bend or angle 21 between these portions of the control member 7 there is a moment of force transmitted through the angle or bend 21 which works in a direction opposite to the transmitted moment of force. This is transmitted to the flexible portion 20 causing it to how, all of which is illustrated diagrammatically in FIG'URES and 6 of the drawings.

Since the arm 16 is connected to the relatively flexible flat portion 20 at the point 23 short of the angle or bend 21 when the flexible portion 20 bows the member or arm 16 will be canted so that the contact 17 at the end remote from its point of connection will be moved into contacting relationship with the stationary contact 18 and the contact 17 will be held in this position until the actuating member 6 cools and shortens. Since the gap between the contacts will determine the time setting this device will operate to produce the desired time delay in the circuit.

The transmission of the moment of force from the transverse portion 22 through the angle or bend 21 causes the elongated portion 29 of the control member 7 to change its position. This angle or bend 21 may therefore be termed a moment origin which is defined as the locus of the points about which the transverse portion 22 and the elongated portion 20 rotate in space when the actuating member is caused to expand or vary its length in accordance with variations in current through the heating element therein. This moment origin is a function of the predetermined angle of the bend.

4 FIGURE 7-MODIFIED FORM FIGURE 7 shows substantially the same structure described in the form of the invention shown in FIGURE 1. Hence, the same parts have been given similar character numerals. This form of the invention differs from the form of the invention shown in FIGURE 1 in that the movable arm 16' is connected to the transverse portion 22 between the bend or angle 21 and the point of connection of the control member 6 to the actuating member 7.

In this form of the invention, as the actuating member 5 lengthens, the control member will be stretched by upward movement of the transverse portion 22. Since the movable arm rs is connected to the transverse member 22 it will be canted so that the contact 17 will be brought into engagement with the contact 13 and once again the time delay obtained will be a function of the relative spacing between these contacts.

FIGURE 8MODIFIED FORM This form of the invention (litters from the form of the invention show in FIGURES l and 7 in that it provides an adjustable means on the movable arm for setting the time delay which is more accurate than the manual means for spacing the gap between the contact elements 1'7 and 18.

Thus, in the form of the invention shown in FIGURE 8, the time delay control device generally designated A is shown having a header or support base 31 of a nonconducting or insulating material.

The base 31 is provided with a plurality of circumferentially spaced contact prongs 32a not shown, 32b not shown, 32c 320., 32c, 32 and 32g not shown identical with that shown in the form of the invention illustrated in FIGURE 31. The base 1 is further provided with annular flange 33 about the outer periphery for mounting the container 34 as by welding or any suitable means to provide an airtight hermetically sealed joint.

Mounted in the container is a primary or actuating member 36 and a secondary or control member 37.

T e actuating member 36 is identical with that described in the form. of the invention shown in FIGURE 1 and hence includes a shell or expander element 38 which is struck from an integral piece or member so that it provides a T-bracket 39 at one end to connect the actuating member 36 to the prongs 32a not shown and 32d in the base or header 31 as is shown in FIGURES 3 and 8 of the drawings.

Since the control member 36 is identical with that shown in FIGURE 1 of the drawings it is not more fully illustrated. Its electric conducting wire 40 will be connected by a contact 41 to the prongs 32b not shown and 320 which communicate with the circuit in which the control device is connected. The circuit delivers a variable current to the electric conducting wire 4% and thereby varies the amount of heat delivered by the heating element to the expander element 38 of the actuating member.

' Since the control member 36 is identical with that of the form of the invention shown in FIGURE 1 the materials therein consist of stainless steel or like type of alloy having a high coefiicient of expansion and the relative mass to surface area of the expander element or shell 6 will therefore be regulated by the added thickness of the elements contained therein and the insulation therebetween in order to obtain the desired degree of expansion and contraction with variation in the heat developed by the current delivered to thecoil or wire 40 in the heater.

The end of the expander element or shell 3% remote from the end fixed to the point of reference or base 31 is free to expand and contract relative to the base and is provided with a bracket 44 for connecting the free end of the expander element 38 of the actuating member 36 to the control member 37. The other end of the control u member 37 is connected as by a strip or element to the prongs 32 and 32g not shown in the base 1 as is shown in FIGURES 3 and 8, which prongs are a spaced distance from the prongs 3211 not shown and 32d to which the corresponding end of the actuating member 36 is connected.

FIGURES 8 and 9 further show that the control member 37 comprises an integral element including an elongated relatively flexible portion 50, a bent or angled portion 51 and a relatively short stiff transverse portion 52 which construction is identical with that above described for the form of the invention shown in FIGURE 1 and hence will operate in substantially the same manner. This member, however, differs from that shown in the form of the invention described for FIGURE 1 in that a movable arm 53 is struck from the elongated flexible portion 59 as is more clearly shown in FIGURE 9 of the drawings.

Ailixed to the upper end of the movable arm 53 is a thinner strip-like element 54 which extends downwardly so that a contact 55 at the end remote from the point of afiixation to the movable arm may be spaced from a stationary contact 56 by means of the threaded element 57 threadably mounted in the movable arm 53. The threaded element 57 extends through the movable arm 53 for contact with the strip-like element 54 so that the element 54 may be moved relative the movable arm 53 on threading action of the threaded element 57.

The stationary contact 56 will be connected to one of the prongs 32c and when the actuating member 36 elongates with application of current to the heater member 49 it will, as in the operation of the form of the invention shown in FIGURE 1, cause the control member 7 to stretch, and since the transverse portion 52 is relatively stifi once again the moment of force exerted by this stretching action will work in the opposite direction through the moment origin at the bend or angle 51 and cause the elongated relatively flexible portion to how; the movable arm 53 struck in this portion will move therewith along with its member 54 afiixed thereto so that the contact will be moved into engagement with the stationary contact 56 and the circuit will be closed for the time delay period adjustably set by setting the space gap between the contacts with the threaded member 57.

It is believed obvious that while a make type circuit is shown in the present disclosure that the circuit could also be a break type circuit, that is, the movement of the movable arm would open the switch contacts 17 and 13 or 55 and 56 in the respective forms of the present invention instead of closing them in that this would not constitute a departure from the present invention but a mere matter of design which is well known in the art.

Further, in the present structure, we distinguish this structure from that shown and described in the copending application in that there will be a lag in operation in the present structure on expansion of the actuating member 6 because the control member 7 will have to stretch a certain distance efore the effect of the moment of force will be exerted through the moment origin on the control member to cause the elongated portions thereof to bow.

In the structure shown in the copending application the members are pro-stressed and thus on actuation of the actuating member the response bythe control member '7 and hence the movable arm is instantaneous.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. In a time delay control device to be connected in a current-carrying circuit, a thermally responsive actuating member having one end connected to a point of reference in said control device and communicating with said circuit to allow the free end of said member to expand longitudinally relative to said point of reference in response to thermal changes caused by variations in the current in said circuit, a control member connected between said point of reference a spaceddistance irom said actuating member and directly to the free end of said actuating member, said control member including an angular bend at a point thereon relatively close to the point of connection to said actuating member, said control member having a relatively stilt portion between said bend and the point of connection to the actuating member and a relatively flexible portion on the side of the bend remote from the relatively sitfr' portion, and means in operable relation with the flexible portion of said control member including a switch to be opened and closed on expansion and contraction of said actuating member.

2. In a hermetically sealed time delay control device to be connected in a current-carrying circuit, a thermally responsive actuating member having one end connected to a point or reference in said control device and communicating with said circuit to allow the free end of said met her to expand longitudinally relative to said point of reference in response to thermal changes caused by variations in thecurrent in said circuit, an integral control member connected between said point of reference a spaced distance from said actuating member and directly to the free end of said actuating member, said control member having a long portion and a short portion continuous with said long portion disposed at an angle to said long portion, said short portion being relatively stiff and said long portion adapted to flex on longitudinal expansion of said actuating member, and means in operable relation with said relatively long portion of the control member including a switch to be opened and closed when said long portion flexes due to the movement of said actuating member.

3. In a time delay control device to be connected in a current-carrying circuit, a thermally responsive actuating member having one end connected to a point of reference in said control device and communicating with said circuit to allow the free end of said member to expand longitudinally relative to said point of reference in response to thermal changes caused by variations in the cu rent in said circuit, an integral control member having a length greater than said actuating member and connected between said point of reference a spaced distance from said actuating member and directly to the free end of said actuating member, said control member having a long portion and a short portion continuous with and at an angle to the long portion, said short portion being relatively stiff and said long portion adapted to flex on longitudinal expansion of said actuating member and means forming a switch having a stationary contact and a movable contact, said movable contact connected to and movable with said flexible portion of the control member to open and close said switch.

4. In a hermetically sealed time delay control device to be connected in a current-carrying circuit as claimed in claim 3 wherein means are provided to adjust the relative position of the stationary contact to the movable contact.

5. In a time delay control device to be connected in a current-carrying circuit, a thermally responsive actuating member having one end connected to a point of reference in said control device and communicating with said circuit to allow the free end of said member to expand longitudinally relative to said point of reference in response to the thermal changes caused by variation in the current in said circuit, an integral control member having a length greater than the length of said actuating member and connected between said point of reference a spaced distance from said actuating member and directly to the free end of said actuating member, said control member including an angular bend at a point thereon relatively close to the point of connection to the actuating member, said control member having a relatively short stilt portion between said bend and the point of connection to the actuating member and a relatively long portion on the side of the bend remote from the stiff portion whereby on longitudinal expansion of said actuating member said long portion will flex, and switch means including a stationary contact, and a movable contact, said movable contact mounted on an arm having the end remote from said contact con nected to said flexible portion of the control member whereby said switch will be opened and closed on flexing movement of the flexible portion of the control member.

6.. in a time delay control device to be connected in a current-carrying circuit, a thermally responsive actuating member having one end connected to a point of reference in said control device and communicating with said circuit to allow the free end of said member to expand longitudinally relative to said point of reference in response to thermal changes caused by variation in the current in said circuit, an integral control member having a length greater than the length of said actuating member and connected between said point or"; reference a spaced distance from said actuating member and directly to the free end of said actuating member, said control member having a long portion and a short portion continuous with and disposed at an angle to the long portion, said short portion being relatively stilt and said long portion adapted to flex on longitudinal expansion of said actuating member, a switch including a stationary contact and a movable arm having a contact at the end thereof to coact with said stationary contact, said movable arm having the end remote from said contact connected to said flexible portion near the angle formed in the control member and movable on flexure of the flexible portion of said control member.

7. In a hermetically sealed time delay control device as claimed in claim 6 wherein means are provided on said movable arm for adjusting the stationary contact and movable contact relative to each other.

8. In a hermetically sealed time delay control device as claimed in claim 6 wherein said movable arm is struck from a section of the flexible portion of said control member.

9. In a hermetically sealed time delay control device as claimed in claim 6 wherein said movable arm is provided with means for adjustably positioning the movable contact relative to the stationary contact.

10. In a hermetically sealed time delay control device as claimed in claim 6 wherein the angle on the control member is disposed within 33 /s% of the distance along the control member from its point of connection to the actuating member.

11. in a time delay control device to be connected in a current-carrying circuit, a thermally responsive actuating member having one end connected to a point of reference in said control device and communicating with said circuit to allow the free end of said member to expand longitudinally relative to said point of reference in response to the thermal changes caused by variation in the current in said circuit, an integral control member having a length greater than the length of said actuating member and connected between said point of reference a spaced distance from said actuating member and directly to the free end of said actuating member, said control member having a long portion and a short portion continuous with and disposed at an angle to the long portion, said short portion being relatively stiff and said long portion adapted to flex on longitudinal expansion of said actuating member, a switch including a stationary contact and a movable arm having a contact at the end thereof to coact with said stationary contact, said movable arm having the end remote from said contact connected to the relatively stifl portion at a point intermediate the angle formed on said control member and the point of connection to the actuating member.

12. in a time delay control device to be connected in a current-carrying circuit, a thermally responsive actuating member having one end connected to a point of reference in said control device and communicating with said circuit to allow the free end of said member to expand longitudinally relative to said point of reference in response to thermal changes caused by variation in the current in said circuit, an integral control member having a length greater than the length of said actuating member and connected between said point or" reference a spaced distance from said actuating member and directly to the free end of said actuating member, said control member having a long portion and a short portion continuous with and disposed at an angle to the long portion, said short portion being relatively stiff and said long portion adapted to flex on longitudinal expansion of said actuating member, an arm struck from said flexible portion of the control member and movable on movement of said flexible portion, a switch including a stationary contact and a movable element having a contact at the end thereof to coact with said stationary contact, said movable arm having'the end remote from said contact connected to said arm near the angle formed in the control member and movable therewith when said actuating memberexpands.

13. in the hermetically sealed time delay control device as claimed in claim 12 wherein adjustable means are provided on the arm to adjustably position said movable element to space the movable and stationary contact relative each other.

14. In a time delay control device to be connected in a current-carrying circuit, a thermally responsive actuating member having one end connected to a point of reference in said control device and communicating with said circuit to allow the free end of said member to expand longitudinally relative to said point of reference in response to thermal changes caused by Variations in the current in said circuit, a control member connected between said point of reference a spaced distance from said actuating member and directly to the free end of said actuating member, said control member and said actuating member normally disposed in a state of equilibrium, said control member having a relatively stiff short portion and a relatively long flexible portion continuous with and at an angle to the short portion, said long flexible portion adapted to flex on longitudinal expansion of said actuating member, a switch including a stationary contact and a movable arm having a contact at the end thereof to coact with said stationary contact, said movable arm having the end remote from said contact connected to said flexible portion near the angle formed in the control member and movable on flexure of the flexible portion of said control member.

References tilted by the Examiner UNITED STATES PATENTS 1,111,789 9/14 Freas 200-122 1,118,608 11/14 Wilkinson 200-122 1,215,665 2/17 Landis 200-122 2,243,563 5/41 Hottenroth 200-113 2,321,049 6/43 Schmidinger 200-113 2,412,483 12/46 Warrington 200-122 2,664,483 12/53 Broekhuysen 200-122 2,674,730 4/54 Klebanofl et al 200-113 2,689,289 9/54 Bell 200-122 2,700,084 1/55 Broekhuysen 200-122 2,777,969 1/57 Svensson 200-122 2,809,253 10/57 Broekhuysen 200-122 FORElGN PATENTS 21,540 3/ 13 Great Britain.

20,085 9/ 13 Great Britain.

456,414 5/49 Canada.

BERNARD A. GILHEANY, Primary Examiner.

MAX L. LEVY, RlCHARD M. WOOD, Examiners.

Claims (1)

1. IN A TIME DELAY CONTROL DEVICE TO BE CONNECTED IN A CURRENT-CARRYING CIRCUIT, A THERMALLY RESPONSIVE ACTUATING MEMBER HAVING ONE END CONNECTED TO A POINT OF REFERENCE IN SAID CONTROL DEVICE AND COMMUNICATING WITH SAID CIRCUIT TO ALLOW THE FREE END OF SAID MEMBER TO EXPAND LONGITUDINALLY RELATIVE TO SAID POINT OF REFERENCE IN RESPONSE TO THERMAL CHANGES CAUSED BY VARIATIONS IN THE CURRENT IN SAID CIRCUIT, A CONTROL MEMBER CONNECTED BETWEEN SAID POINT OF REFERENCE A SPACED DISTANCE FROM SAID ACTUATING MEMBER AND DIRECTLY TO THE FREE END OF SAID ACTUATING MEMBER, SAID CONTROL MEMBER INCLUDING AN ANGULAR BEND AT A POINT

Images