US3838371A

US3838371A - Mounting assembly for a transformer and relay control device

Info

Publication number: US3838371A
Application number: US00442980A
Authority: US
Inventors: M Willette
Original assignee: Honeywell Inc
Current assignee: Honeywell Inc
Priority date: 1974-02-14
Filing date: 1974-02-14
Publication date: 1974-09-24
Anticipated expiration: 1991-09-24

Abstract

A simplified and cost reduced mounting plate and cover are provided for a transformer and relay normally used in the heating and cooling control industry. A mounting plate with an integral end bell for the transformer mounts the transformer and relay so that a second member can be placed over a portion of the transformer and the relay to form a complete housing or enclosure.

Description

United States Patent Willette Sept. 24, 1974 MOUNTING ASSEMBLY FOR A 2.494.350 1/1950 Mittermaier 336/65 x TRANSFORMER AND RELAY CONTROL 2.699.531 1/1955 Massar i 336/67 X DEVICE 2903,66] 9/1959 Goffstein 336/65 [75] Inventor: Merton J. Willette, Edina, Minn. primary Harris [73] Assignee: Honeywell Inc., Minneapolis, Minn. Agent) or Firm Alfred Feldma" [22] Filed: Feb. 14, 1974 [57] ABSTRACT PP O- 2, 80 A simplified and cost reduced mounting plate and cover are provided for a transformer and relay nor- 52 us. Cl 335/278, 336/65, 336/67 mally used in the heating and Cooling Control industry- [51 Int. Cl. non 7 00 A mounting Plate with an integral end for the 58 Field Of Search 335/278; 336/65, 67 transformer mounts the transformer and relay so that a a second member can be placed over a portion of the 5 References Cited transformer and the relay to form a complete housing UNITED STATES PATENTS 6/1927 Thordarson 336/65 X or enclosure.

9 Claims, 6 Drawing Figures MOUNTING ASSEMBLY FOR A TRANSFORMER AND RELAY CONTROL DEVICE BACKGROUND AND SUMMARY OF THE INVENTION It has been common in the heating and cooling industry to provide furnaces with a low voltage control that operates line voltage fan motors and auxiliary circuits. These controls are generally referred to as fan centers and are usually built upon a mounting plate that covers a conventional electrical junction box. Placed on the mounting plate are a relay and its protective cover, along with a low voltage control transformer. Units of this type are commercially available from the Honeywell Inc.

Fan center or control devices of the type just mentioned are typically manufactured by starting with a flat, heavy mounting plate that covers a conventional 4 X 4 electrical box and then individually mounting a finished low voltage transformer and covered relay upon the mounting plate. The units are then interconnected to provide the necessary control circuitry. The mounting plate is adapted to be mounted on a 4 X 4 electrical junction box or other enclosure of similar size and connected to the circuit or circuits passing through the junction box as well as low voltage control circuits.

Due to the highly competitive nature of this particular market, any cost saving that can be generated creates-a competitive advantage. The present invention is directed to a fan center type device which utilizes a combined transformer and relay control device wherein a number of the conventional parts are eliminated and replaced by two parts that serve a multiple number of functions as compared to the prior art devices. The present invention utilizes a mounting plate that has formed integrally with it one end bell of the control transformer. The mounting plate provides a convenient mounting location for not only the transformer but also for the relay. The relay is then connected to a winding of the transformer, and the transformer and relay are enclosed by a second member. The mounting plate and the enclosure member thereby provide the function normally provided by four parts in a conventional fan center type of control. The economies in reducing the number of parts by one-half and the conservation of materials is very important in this competitive market, as well as, in the concept of the conservation of materials. The present device with its unique construction meets the safety requirements of Underwriters Laboratories for component recognition. It can be manufactured of a lighter gauge material than would be required if the parts were fabricated as individual members, as has been done in the prior art units.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a schematic representation of the transformer and relay of the present unit;

FIG. 2 is atop view of a preferred embodiment;

FIG. 3 is a side view of a preferred embodiment;

FIG. 4 is a cross section taken along lines 44 of FIG. 2;

FIG. 5 is an elevation of just the mounting plate means of the present invention, and;

FIG. 6 is a top view of a second embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 a schematic representation is provided of a combined transformer and relay control device 10 which includes a transformer 11 having a primary winding 12 and a secondary winding 13. The primary winding is connected through a hole 19 by conductors I4 and I5 to a source of alternating current potential 16 which would normally be I volts at 60 hertz.

The low voltage winding 13 is connected by conductor 17 to a terminal 20 mounted on an insulating terminal board 21. The terminal board 21 includes

additional terminals

22, 23, 24, and 25. The

terminals

22 and 23 are used for convenience in making circuit connections from incoming control devices. A typical incoming control device, when the present invention is used as a fan center in a heating-cooling furnace, would be a thermostat, a gas valve, and a contactor to control an air conditioning compressor. The present invention, while specifically described as a fan center for use with a heating and cooling type of control system, could be used for control of any type of relay controlled load by means of a low voltage control circuit, and therefore no specific external circuitry is disclosed.

The transformer secondary 13 is also connected by a conductor 26 to terminal 24 and by conductor 27 to a relay means generally disclosed at 30. The relay means 30 includes a relay coil 31 and relay contact 32. The relay contacts 32 are connected to three

conductors

33, 34, and to provide switching control between the conductor 34 and either 33 or 35 depending on the condition of the relay means 30. The relay means 30 is further connected by conductor 36 to terminal 25. g

In the schematic disclosed in FIG. 1, it is apparent that a step down type of transformer is provided so that a low voltage control circuit can be connected externally to the device to energize the relay means 30 by completing a circuit between

terminals

20 and 25. The operation of relay means 30 in turn operates the relay contacts 32 to switch between the

conductors

33, 34, and 35 in a well known fashion.

In FIGS. 2 and 3 are two views of the novel combined transformer and relay control device of the present invention. A mounting plate means 40 is formed from a relatively flat metallic member with two

upstanding portions

41 and 42. The upstanding member 42 has formed from it a box like housing 43 that in turn forms an end bell for a transformer. This mounting plate means is shown by itself in cross section in FIG. 5. A further upstanding projection 44 (FIGS. 4 and S) is formed through the mounting plate means 40 and acts as a convenient mounting for the relay means 30, which will be described in connection with the assembled device. A further upstandin g member 45 is provided in the mounting plate means 40 to provide a convenient stop for the transformer 11 which is mounted in the assembled device. It can be seen by considering FIG. 5 that a flat base member and two upstanding wall members are integrally formed from a single piece of material and that one of the upstanding members 41 has a box like or end bell configuration 43 that is designed to enclose a first side of a transformer coil means. The end bell 43 further has an upstanding projection 46 that acts as a convenient plate for attachment of the end bell 43 by means of the screw 47 to the balance of the device.

As will be noted in FIGS. 2 and 3 the transformer 11 is mounted on the mounting plate means so that the end bell 43 covers one side of the transformer 11 while the second side of the transformer 11 is covered by a second housing means 50. The housing means is made up of a number of

wall members

51, 52, 53, and 54 which extend adjacent to the mounting plate means 40 and the transformer 11. The member 51 abuts against the transformer 11 forming an end bell for that side of the transformer 11 as well as part of the housing means 50. A top member forms a general cover for the housing means 50 and further supports the terminal board 21 of an insulating character which in turn supports the

terminals

20, 22, 23, 24, and 25. As can be seen in FIG. 3,

wall members

52 and 54 abut the inside of upstanding member 42 to help hold housing means 50 in place.

In the preferred embodiment the housing means 50 is fabricated of a nonmagnetic material such as aluminum. This precludes magnetic fiux from the transformer ll finding a convenient magnetic path through the device and creating possible hum problems. The mounting plate means 40 and the second housing means 50 could be fabricated of molded plastic or fiberglass if that was found to be convenient and would not necessarily have to be formed from metal as is the normal custom. It can be seen that the second housing means 50 provides a convenient mounting area for the terminal board 21, as well as, forming an enclosure that completely encircles or contains the relay means 30 as well as forming a second end bell for the transformer 11.

The various FIGS. 2, 3, 4, and 5 disclose various views of the preferred embodiment and similar numbers have been assigned to the similar parts of the various figures and the schematic drawing of FIG. 1. It is believed that the description to this point makes it quite clear that a very highly simplified and inexpensive structure has been provided that eliminates many of the parts formally used in comparable prior art devices. This reduction in the number of parts provides a cost saving and a conservation of materials. As a result of this it is believed that the art has been distinctly advanced. Also the present device, since the mounting plate means 40 and the second housing means 50 form an enclosure, can be manufactured of a lighter gauge material than would otherwise be allowable under normal safety standards.

In FIG. 6 a second version of the combined transformer and relay control device is disclosed. A mounting plate means 40 is utilized which has an end bell 43 integrally attached to the mounting plate means 40. An upstanding portion 42 and an upstanding portion 41' are also provided which are similar in structure to that disclosed in FIGS. 2 through 5. The main difference between the device disclosed in FIG. 6 and that disclosed in FIGS. 2 through 5 is in the second housing means 60. The second housing means again mounts an insulating terminal board 21 but the second housing means 60 is of sufficient size so that it covers the transformer 11 thereby forming an end bell and enclosure for the relay means 30. The device disclosed in FIG. 6 can be used in place of that of FIGS. 2 through 5 if it is desirable to completely enclose and protect the transformer lamination structure as opposed to leaving the lamination structure exposed as is done in the embodiment disclosed in FIGS. 2 through 5. Once again the structure can be manufactured from a convenient metal or can be molded plastic, if desired.

It is quite obvious that a highly simplified form of combined transformer and relay control device known as a fan center is disclosed in the present invention. The simplification of parts is a distinct manufacturing advantage and saves material. This saving is passed on to the customers as a lower product cost and provides a new and unique device over a combined transformer and relay control made up of fabricated individual components mounted on a flat plate. The present invention could be modified in addition to those disclosed in FIGS. 2 through 6, and the applicant wishes to be limited in the scope of his invention solely by the appended claims.

The embodiments of the invention in which an exclusive property or right is claimed are defined as follows:

1. A combined transformer and relay control device, including: a transformer including a magnetic structure and electric coil means; relay means electrically connected to said coil means and adapted to derive an electrical operating potential from said coil means; mounting plate means to support said transformer and said relay means; said mounting plate means including first housing means attached to said plate means to form an end bell for said transformer to enclose a first side of said electrical coil means with said end bell adjacent said magnetic structure; and second housing means forming an enclosure for said relay means and a second side of said coil means by said second housing means including wall members adjacent said mounting plate means and said magnetic structure.

2. A combined transformer and relay control device as described in claim I wherein said enclosure wall members are adjacent said mounting plate means and a side of said magnetic structure adjacent said relay means and said second side of said coil means.

3. A combined transformer and relay control device as described in claim 2 wherein said enclosure wall members are formed as an integral unit.

4. A combined transformer and relay control device as described in claim 3 wherein said integral unit is formed of a nonmagnetic material.

5. A combined transformer and relay control device as described in claim 3 wherein said integral unit is fabricated of an electrically insulating material and supports terminal means.

6. A combined transformer and relay control device as described in claim 1 wherein said mounting plate means and said first housing means are formed from a single piece of material as an integral unit.

7. A combined transformer and relay control device as described in claim 6 wherein said mounting plate means and said first housing means are fabricated of an electrically insulating material.

8. A combined transformer and relay control device as described in claim 6 wherein said enclosure wall members are adjacent said mounting plate means and a side of said magnetic structure adjacent said relay means and said second side of said coil means.

9. A combined transformer and relay control device as described in claim 8 wherein said enclosure wall members are formed as an integral unit from a nonmagnetic material.

Claims

2. A combined transformer and relay control device as described in claim 1 wherein said enclosure wall members are adjacent said mounting plate means and a side of said magnetic structure adjacent said relay means and said second side of said coil means.