US2890308A - General purpose electric relay - Google Patents

Description

June 9, 1959 M. DEBREY 2,890,308

GENERAL PURPOSE ELECTRIC RELAY Filed Nov. 20, 1957 2 Sheets-Sheet 2 INVENTOR MICHAEL DE BREY ATTORNEY United States Patent O GENERAL PURPOSE ELECTRIC RELAY Michael Debi-ey, Springfield, Ill.

Application November 20, 1957, Serial No. 697,583 Claims. (Cl. 200103) This invention relates to improvements in electromagnets and switch mechanisms operated thereby, and it contemplates a general purpose electric relay which may be used in connection with electric refrigerators and freezers, automatic heating plants, ventilators, voltage regulators for alternating current generators, and various other electrical apparatuses,

One object of the invention is to provide an improved electromagnet for a relay or the like in which the energizing coil is totally enclosed by electrical conductive material so that the relay will not cause radio interference.

Another object is to provide an improved electromagnet of this character which is armatureless but has two coacting magnet elements of magnetizable material relatively movable toward and from each other and energized by a single solenoid coil, thereby greatly increasing the power and range of use of the electromagnet over one in which an armature moves toward and from the magnetic poles.

Another object is to provide an improved relay in which the magnet opens at the neutral line of the energizing coil in order to minimize sticking of the magnetized elements at the time of discharge.

Another object is to provide in a relay an improved electromagnet in which the magnetized elements totally enclose the coil so that no magnetism can go astray and no nearby outside magnetic substance can interfere with the operation of the relay.

Another object is to provide an electromagnet of the character indicated in the preceding paragraph, in which the coil is within two cup-shaped elements having concentric inner and outer portions with the closed ends of the elements disposed adjacent the true poles of the coil and with their open ends in spaced and opposed relation to provide the magnet with four operative poles, thereby providing a relay which will be highly effective in operation when the energizing current is of the low value used in many applications, and which will be powerful enough, when used in a voltage regulating system, to eifectively operate throughout a voltage range of 40 to 150 volts.

Another object is to provide an electromagnet of the above indicated character with means to ventilate and cool the enclosed coil.

With the above and other objects and advantages in View, the invention resides in the novel combinations and arrangements of parts and the novel features of construction hereinafter described and claimed, and illustrated in the accompanying drawings which show the present preferred embodiment of the invention.

In the drawings:

Fig. l is a side elevation, with parts broken away and in section, of the preferred embodiment of the invenwith the improved relay;

Fig. 2 is a vertical sectional view taken on the line 2-2 in Fig. 1;

Fig. 3 is a detail horizontal section taken on the line 3--3 in Fig. 2;

Fig. 4 is a detail vertical section taken on the line 4-4 in Fig. 2;

Fig. 5 is a detail horizontal section taken on the line 5-5 in Fig. 2; and

, Fig. 6 is a detail section showing one means for preventing turning or rotation of the movable switch-actuating element of the relay.

Referring more in detail to the drawings, the numeral 10 denotes an upright panel of insulating material from the front of which the improved relay is supported. The electromagnet comprises a coil 11 wound on a spool 12 of insulating and non-magnetic material, the coil being substantially enclosed by two preferably cup- shaped magnet elements 13 and 14 made of material which will be magnetized by a current passing through the coil but which will lose their magnetism when the coil is not energized, They are preferably made of a very soft steel, and preferably each has a solid but perforated end wall from which projects a tubular core portion and a cylindrical outer portion, such portions at the open ends of the cup-like elements being ydisposed in opposed but spaced relation, as seen in Figs. 1 and 2. The upper element or cup 13 is rigidly supported from the panel by fastening its end wall 14 by screws 15 to two laterallyspaced horizontal metal brackets 16, the reduced and threaded ends of which are passed through the panel and fastened by nuts 17. The cylindrical outer portion 18 of the upper cup surrounds and is spaced from the upper half of the coil and a few air holes 19 are provided in the end 14' to permit of air circulation over the coil. The cylindrical and tubular core portion 20 of the upper cup has a tight fit in the upper half of the spool 12, and an adhesive may be used to fasten these parts, so that the coil 11 will be supported in a perpendicular position by the upper cup.

The lower element or cup 14 is movable and has a closed lower end wall with perforations 19, an outer cylindrical wall 21 surrounding and spaced from the lower half of the coil and a cylindrical tubular core portion 22 with an outer diameter substantially less than the interior of the spool 12 so that the cup 14 may move freely upon the lower half of the coil. This movable magnet element 14 is xed to a central switch actuating stem or rod 23 which extends through both of the core portions 20 and 22. The upper part of the stem 23 is freely slidable in the bore of the core `20 while its lower portion is xed in the bore of the core 22, as by providing an enlarged or knurled portion 24 on the stem and driving it into the bore of the core 22. Stem 23 is made of suitable non-ferrous metal.

Fig. 1 of the drawings shows one possible use of the relay in which three independent circuits may be used in the operation of a freezer or refrigerator system for example. Switch mechanism operated by the projecting lower end of the stem may be used to start and stop a compressor-driving electric motor M according to the operation of a thermostatic switch S in the freezer box controlling the ow of current through the relay coil from a generator G or other source of electrical power, while switch mechanism operated by the projecting upper end of the stem 23 operates an independent power circuit that might include a signal L to indicate that the load circuit through the motor M is open.

The switch for controlling the motor M, or lany other load, comprises a metallic contact-carrying arm 27 mounted to swing vertically beneath the electromagnet on a pivot 28 -in brackets 29 having reducedthreaded ends.

held in openings in the panel by nuts at the rear thereof. At the front end of the lever 27 is a switch contact 30 having a screw stem adjustably threaded through a vertical hole and held in adjusted position by a set screw 31. Set in an intermediate portion of the switch lever 27 is a tubular bushing 32 of insulating material that freceives a reduced screw threaded portion 33 formed on the bottom of the stem or rod 23. Nuts 34 on the end 33 above and below the bushing may be held in ad justed positions by set screws 35 to provide a connection that 'will permit lever 27 to swing but `without lost motion. A coacting switch contact 36 is carried by a leaf spring 37 on the top of a metal supporting and protecting arm 38 clamped on a bracket 39 on the panel. A screw 40 fastens the inner end of the spring to the arm 38 .and the reduced outer portion of the latter underlies the contact-carrying outer portion of the spring. The bracket 39 has a reduced threaded end fastened in an opening in the panel by a nut 41. The arm 38 is clamped on top of the bracket by a headed screw 42 so that when the latter is loosened the arm and its spring may be swung laterally to permit of easy access to the two contacts 30 and 36 for repairs or replacement. The circuit of the motor M includes a conductor 43 between the generator G `and a clip or lug under the nut 41 of the metal bracket 39, a conductor 44 between the generator and the motor, a conductor 45 between the motor and a binding post or bolt 46 in the panel and a flexible conductor wire 47 between that bolt and the switch lever 27. A manually actuated cutout switch 50 is included in the motor circuit. When switch 50 is closed and the contacts 30 and 36 are engaged, the current will flow from the generator through conductor 43, parts 39, 38, 37, 36, 30, 27, 47, 46, 45, 50 to the motor and from the latter through conductor 44 to the generator. It is to be understood that the motor M represents any suitable load depending upon the use of the relay.

As seen in Fig. l, the ends of the relay coil 11 are connected to two binding posts or bolts 53 and 54 mounted on the panel. The thermostatically operated switch S, or any other kind of switch depending upon the use of the relay, may be included in a conductor 55 extending between bolt 53 and the generator G, the latter being `also connected by a conductor 56 to the bolt 54. It will be seen that when the switch S` is closed the coil will be energized and each of the cups will receive an equal charge of magnetism.

The switch mechanism operated by the projecting upper end of the stem 23 includes a contact 58 adjustable on the top of the stem and coacting with a contact 59 carried by the outer free end of a leaf spring 60. The rear end of the spring 60 is fastened by a screw 61 and metal `spacing sleeve to the under side of a metal bracket arm 62 projecting forwardly from the panel and 0verlying the spring. This rigid arm has a reduced threadu ed end extending through a hole in the panel and fastened by a nut 63. At the outer end of the arm 62 in vertical alinement with the contacts 58 and 59 is un adjustable stop 64 which has a shank or stem 65 screw threaded through the arm 62. A screw driver kerf in 65 permits the stop 64 to be adjusted, and it is then locked by a set screw 66. This stop limits the upward movement of the stem 23 and with the rigid arm 62 absorbs the upward thrust of the stem and movable cup 13 'when the coil is energized. In order to brace the arm 62 a fixed cross bar 67 is disposed above its outer portion with a plate 68 of rigid electrical insulation, disposed between these parts and carried by the cross bar. This horizontal bar 67 is parallel with the panel and has its ends supported by tubular posts 69 which rest on the tops of the brackets 16 and are fastened to the latter by bolts 70 extending through the cross bar and posts.

The power circuit controlled by the contacts 58 and 59 includes a source 71 of electrical energy, usually of relatively low voltage, and the load L which is shown 4 diagrammatically as an electric lamp but which may take other forms depending upon the use of the relay. A conductor 72 connects one terminal of the battery 71 to a clip or lug under the nut 63. The other battery terminal is connected by a conductor 73 to the lamp. Another conductor 74 connects the lamp to `a lug under one nut 17. This power circuit also includes the two cups 13 and 14 and the stem 23. Since there is a loose sliding movement of the stem 23 in the core 20 and a positive electrical connection between the portion 24 of the stem 23 and the core 22, I provide a iiexible wire connection 75 between the two cups. This is `shown in Fig. l `as a wire `coil having its ends soldered to the outer portions `of the cups. The movable cup 13 may be prevented :from turning or rotating by any suitable means, but as seen in Figs. 1 and 6, the outer cylinder is formed with a vertical slot 76 which receives the at reduced end 77 of a bracket or 'stud 78 of nonmagnetic material tixed to the panel by having a reduced and threaded end fastened in a hole in the panel by a nut. As shown in Fig. 2, the contact 58 is made adjustable on the stem 23 by providing it with a reduced stem 81 screw threaded into the end of the stem and carrying a lock nut 82 as seen in Fig. 2. In Fig. 2 the numeral 80 designates a magnetic insulator applied to the lower end of the core portion 20 of the upper cup 1.3. lt may be a disk of any tough nonmagnetic metal having a thickness of from .025 to .050, and serves as a magnet buffer and permits of a more rapid vibration. The bottom face of this part 80 is below the bottom edge of the cylindrical outer portion 18 and it prevents any possibility of the cups 13 and 14 contacting each other.

When the motor M is stopped by the separation of the contacts 30, 36, the power circuit is closed by the engagement of the contacts 58, 59. Current then l'lows from the battery or other source of power 71 through conductor 72, stop arm 62, spring 60, contacts 59 and 58, stem 23, connection 24, cup 14, flexible connector 75, cup 13, and the bracket 16 to which conductor 74 is fastened to the lamp or other load L, and then `from the latter through conductor 73 to the battery. This circuit is broken when the thermostatic switch S opens, or another form of switch is opened, to deenergize the cups so that the weight of the parts 23, 14 and 27 causes the contacts 30, 36 to close the motor circuit. The weight of these parts makes it unnecessary to employ springs in the relay.

The disclosed multiple circuit relay has many uses and advantages. The cups 13 and 14 not only protect the coil from outside mechanical injury but they shield it against l nearby magnetic substances that might interfere with the operation of the relay and also prevent radioactive waves radiating beyond the cups. The relative movement of the cups and the provision of the air holes in their closed ends causes an air pumping action around the coil to aid in cooling it. But more importantly, the cups, if they have the core portions, form two electromaanetic elements which are equally energized by the true poles of a single coil, and thus the device is provided with four effective poles to produce a very powerful magnetic relay that will operate eiciently on a minimum amount of energy for a given operation. The relay magnet opens at the neutral line of the coil, and when a current is passed through the coil each cup will get an equal charge, one from one pole of the coil and the other from the opposite pole. If the current is passed through the coil in a given direction the polarity will be as indicated in Fig. 2, in which the outer portion of the cup 13 is designated South while its core portion is designated North, and the outer portion of the cup 14 is designated North while its core portion is designated Southf By thus operating the electromagnets at the neutral line of the charging coil, the relay is given a double amount of power for making and breaking the switch contacts. This eihciency permits of the use of much less current in the coil, and results in a longer life for the contacts of the switch S.

From the foregoing, taken in connection with the accompanying drawing, it will be seen that novel and advantageous provision has been made for carrying out the objects of the invention, and while preferences have been disclosed, attention is invited to the possibility of making variations within the scope of the invention as claimed.

I claim:

l. In a relay, an upright supporting plate of insulating material, a pair of laterally spaced brackets of conducting material projecting horizontally from the front of said plate, a pair of upper and lower cup-shaped electromagnet elements each having an end portion from one face of which projects a tubular core and an outer concentric wall, the open ends of the elements being in opposed and spaced relation, means for electrically connecting the end portion of the upper element to said brackets, a tubular solenoid coil within said elements and having its upper half supportingly fixed to the core of the upper element and its lower half spaced from the core of the lower element; a switch-operating rod of conducting material extending through the cores of the two elements and iixed electrically to the core of the lower element to support the latter, a switch contact on the projecting upper end of said rod, a stop arm of conducting material projecting horizontally from said plate in a plane above said brackets with its outer end disposed over the longitudinal axis of said rod, a resilient switch lever carried by and disposed under said arm and carrying a coacting switch contact, a vertically adjustable stop on said arm engageable by said switch lever to limit the upward movement of said rod when said coacting contacts are engaged, and means for bracing said stop arm comprising a pair of laterally opposed upright posts rising from the intermediate portions of said brackets, and a cross bar tixed to said posts and extending in bracing contact with the top of said stop arm, and a ilexible electrical connection between the outer concentric portions of the two elements.

2. The relay of claim l in which the upper end of said coil is spaced from the end portion of said upper cupshaped element and the last mentioned end portion is formed with a plurality of air holes, and in which the end portion of said lower cup-shaped element is also formed with a plurality of air holes, whereby when said rod and the attached lower element are moved the air surrounding said coil will be agitated.

3. The relay of claim 1 in which a magnetic insulator is carried by an end of one of the opposed tubular cores of the cup-shaped elements to prevent the'latter from coming into contacting engagement.

4. The relay of claim l together with means for preventing the lower cup-shaped element and its supporting rod from rotating, said means comprising a stud carried by said plate and having an end projecting into a vertical slot formed in the outer concentric wall of said lower element.

5. The relay of claim 1 together with a second switch mounted on the lower portion of said plate and operatively connected to the projecting lower end of said rod.

References Cited in the tile of this patent UNITED STATES PATENTS 506,282 Timmis Oct. 10, 1893 706,012 Bourne Aug. 5, 1902 985,509 Carpenter Feb. 28, 1911 1,000,074 Collier Aug. 8, 1911 1,019,045 Horton Mar. 5, 1912 1,559,738 Brockway Nov. 3, 1925

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