US2300974A

US2300974A - Molded article

Info

Publication number: US2300974A
Application number: US328273A
Authority: US
Inventors: Albert B Rypinski
Original assignee: METROPOLITAN DEVICE CORP
Current assignee: METROPOLITAN DEVICE Corp
Priority date: 1940-04-06
Filing date: 1940-04-06
Publication date: 1942-11-03
Anticipated expiration: 1959-11-03

Description

lNav. 3, 1942,. .Q -B. RYPlNsKl v I 2,300,974

Y uoLnEn ARTICLE Filed April 6, `1940 INVFNTOR ALBERT B. RYPINSKI ATTORNEY o Patented Nov. 3, 1942 MOLDED ARTICLE Albert B. Rypinsk-, Laurelton, N. Y., assignor to Metropolitan Device Corporation, Brooklyn, N. Y., a corporation of New York Application April 6, 1940, Serial No. 328,273

7 Claims. (C1. 200k-168) The invention herein disclosed relates to an article constructed'from molded material and including elements fastened thereto, such for example as the case, base or support of an electrical de-vice.

UIn -certain articles, particularly electrical devices, it is expedient to mold or stamp certain parts such as supports, bases, cases, and other non-conducting partsffrom electrical insulating material such, for example, as Bakelite. Specific examples of this kind are switches and circuit breakers of the smaller sizes, the cases for which may be molded from moldable electrical insulating material. These cases have various parts secured thereon such as stationary contacts, conductor strips and terminals. Such parts must be Very secure so that strong pressure on terminalswill not cause displacement of the parts.

.- `It is one of the primary objects of this invention to secure relatively thin strip material, terminals or plates into a relatively thin wall of molded material. This maybe done after the wall is molded. Another ob-ject is to accomplish the securing of .thin plates in thin walls Without the necessity for lateral punches in the molding operation.

Articles of this kind are commonly molded in a two part mold, the parts of which are separable in a direction perpendicular to the plane of separation. Where an article has openings, grooves, etc., that require -punches or cores which extend perpendicular to the direction of separation of the mold parts, special, expensive equipment is required, the molding operation is slower and the yarticle is correspondingly more expensive. It is common lpractice in design of parts for molding to have a punch from the top of the mold meet a punch from the bottom of the mold, the two intersecting in a common plane but displaced one from the other, to form a lateral opening. This method is utilized herein to prepare a thin moldable wall to receive and retain parts secured thereto in accordance with the invention.

The walls of molded articles need to be relatively thin because the curing time or time required for lthe material to form a homogenous mass of adequate strength, varies with the thickness of the wall.

In accordance `with the invention a thin wall is molded with a slot from the top and with an intersecting but displaced slot in the same wall from the bottom. One loose member ie slid in tothe end of the slot from the top and a second loose mem-ber is installed against the end of the slot from the bottom. Then the members are secured together. The boundaries of the slots prevent movement of the members with relation to the wall, after they are secured together.

A circuit breaker embodying the invention is disclosed, by way of example, in the accompanying drawing and described in detail below. In the drawing:

Fig. 1 is a plan view with the cover partialli7 broken away;

Fig. 2 is an end elevation of the same; and

Fig. 3 is a transverse section taken on the line 3 3 of Fig. 1.

The circuit breaker illustrated in the drawing is of the kind disclosed in my copending applications, Serial Nos. 309,521 and 321,022, iiled December 16, 1939, and February 27, 1940, respectively. .These circuit breakers primarily include a case and an operating unit consisting of rotatable parts. The case constitutes an enclosure for .the operating parts and a support for the stationary contacts which are positioned within the 'case for cooperation with contacts on one of the movable parts. These stationary contacts are mounted on contact strips that are secured to the case in such relation that connections may be made thereto through terminal screws accessible on the outside of the case. The case is molded from Bakelite or some equally good electrical insulating material and the contact `strips must be mounted thereon such that strong pressure on the terminal screws will not cause displacement of the contact strips.

fThe circuit breaker disclosed for the purpose of illustrating this invention is a single circuit breaker and includes a case 'I open at the bottom and molded in one piece from Bakelite or other Inoldable electrical insulating material. This case has a compartment having an opening through the top. rIn the compartment there is mounted an operating unit, the unit 2. This operating unit is inserted in the compartment through the bottom of the case and a cover 3 is provided for the case and en-closes the unit within the case, the cover being provided with an opening through which a linger piece t extends. The ringer piece is provided for the manual operationof the circuit breaker.

For the circuit breaker unit, there a pair of stationary contacts (not shown), one at each end of the compartment in which the unit is mounted. These contacts are connected to or mounted upon contact strips which extend through openings in the case andthat .are secured to the case. fIhe contact strips are identical and mounted in the same Way. For this reason lbut one of the contact strips and the mounting thereof on the case will be described.

At the end of the section of the case in line with the compartment in which the unit 2 is mounted, there are provided two grooves, entering from opposite edges of the end wall and having overlapping sections intermediate the opposite edges of the end wall. One of these grooves, 5, enters from the top edge of the case; it is at the inner surface of the end wall 6, parallel to the plane of the wall and terminates at a point I intermediate the edges of the wall. The other groove 8 which is of lesser width than the groove 5 enters from the opposite or lower edge of the end wall; has a section 9 which overlaps the groove 5 and terminates at a point I0 intermediate the edges of the wall. The grooves lie in parallel planes and are so related that an opening is effected through the wall at the overlapping sections of the grooves. Since the overlapping section 9 of the groove 8 is of lesser width than the groove 5, shoulders are formed on each side of the opening effected by the grooves at the point of communication of the overlapping sections or intermediate the ends of the opening.

As will be observed from the drawing, the case I is rectangular. It is molded in a die which separates along a plane transverse to the side and end walls and the parts of which separate by relative movement parallel to the grooves 5 and 8. All of the cavities of the case are thus made by cores or punches extending from the mold parts and parallel to the line of movement along which separation of the mold parts is eiected. Thus the compartment for the operating unit and the groove 8 are formed by cores or punches extending from the mold part which forms the bottom of the case. Similarly the groove 5 and the passage I I inwardly of the groove 5 are formed by punches extending from the mold part that forms the top of the case and parallel to the line of separation of the mold parts.

In the groove 5, there is placed a square nut I2y of a width, between flats, such that opposite edges engage the sides of the groove and the face engages the shoulders formed intermediate the ends of the opening effected by the overlapping sections of the grooves 5 and 8. When this nut is inserted in the groove, it is provided with a central, extruded, cylindrical extension I3 axially aligned with the tapped opening through the nut. The nut seats in the bottom of the groove 5 and the extension I3 extends through the opening eected by the overlapping sections of the grooves. The nut is thus engaged on three edges and part of one face.

Within the groove B the end section of a connector strip I4 is received. This connector strip carries on its inner end a contact (not shown) and extends along the bottom of the end wall and along the groove 8. The end portion of the connector strip is received in the section 9 of the groove 8. An opening is provided through which the cylindrical extension I3 passes when the conductor strip is placed in the groove. The end of the strip abuts against the upper edge of the groove 8.

When the nut and conductor are in the respec- 7 tive grooves as above described, the cylindrical extension is rolled over forming a flange or bead I5 by which the nut and conductor strip are rigidly secured together. The passage II provides space in which an anvil may be held to take up fil) all)

the strains incident to the rolling over 0f the eX- tension I3. In addition, it simplies the placing of the nut in place, and in the finished case forms a vent through which gases resulting from arcs may freely pass out of the case. The nut I2 forms a tapped hole for the terminal screw I6 through which a conductor may be connected to the strip I4.

The conductor strip I4 extends under the end wall of the case, a space I'I being provided for this purpose. These strips are covered and insulated by the bottom I8 Which is secured to and closes the bottom of the case. The circuit breaker unit has an adjusting screw I9 with which the breaker is set for its rated capacity. Since the operating parts must be assembled from the bottom of the case, once the terminal ttings have been secured to their respective nuts, these parts are xed in the case. Since they prevent the removal of the circuit breaker unit once they are in place, the securing means become one means for rendering the adjustment of the circuit breaker inacessible. The cover is permanently secured on the case by -rivets or screws 20 and 2| which extend through the cover, the case and the bottom strip I3.

From the foregoing description of the embodiment of the invention illustrated in the drawing, it will be seen that by this invention there is provided an arrangement by which parts may be rigidly secured in a thin wall of a molded article without the necessity of utilizing lateral cores or punches in the forming of the article. In addition there is in the specic circuit breaker disclosed an arrangement whereby the breaker, before the cover is assembled thereon, may be tested and adjusted and when the cover is in position the adjusting screw is inaccessible.

It will be obvious that various changes may be made by those skilled in the art in the details of .the embodiment of the invention disclosed in the drawing and described above within the principle and scope of the invention as expressed in the appended claims.

I claim:

l. In a device of moldable material, the combination comprising a wall having an opening therethrough effected by overlapping sections of grooves lying in parallel planes entering from different points at the edge of the wall and of different width at the overlapping sections, an element in one of the grooves having an opening therethrough, and an internally threaded fastening element in the other of said grooves having an extension thereon passing through the opening in the rst mentioned element and securing the two elements together.

2. In a device of moldable material, the combination comprising a wall having an opening therethrough effected by overlapping sections of grooves lying in parallel planes entering from diierent points at the edge of the wall and of diierent widths at the overlapping sections, an element in one of the grooves having an opening therethrough, and an internally threaded fastening element in the other of said grooves having a cylindrical extension thereon extending through the rst mentioned element and securing the two elements together.

3. In an electrical device, the combination comprising a support of moldable, electrical insulating material including a wall having an opening therethrough effected by overlapping grooves lying in parallel planes, entering from opposite edges of the wall and of diii'erent Widths at the overlapping sections, a conducting strip having an opening therethrough in one of the grooves, a tapped fastening device and terminal screw socket in the other groove having a cylindrical extension extending through the conducting strip and securing the strip.

4. In an electrical circuit closing and breaking device the combination comprising a case of molded electrical insulating material including a Wall having an opening therethrough eiected by overlapping sections of grooves lying in parallel planes and entering from opposite edges of the Wall and of different widths at the overlapping sections, a contact strip in one of the grooves having an opening therethrough, a tapped nut in the other groove having a tapped, axial, cylindrical extension extending through the opening in the contact strip and rolled over to secure the contact strip thereto, and a terminal screw in the nut.

5. In a device of moldable material, the combi nation comprising a Wall having an opening therethrough intermediate the edges thereof effected by grooves entering from different points at the edges of the Wall and having sections overlapping transversely of the plane of the wall forming the opening through the Wall, an element in one of the grooves engaging the side edges thereof, and another element in the other groove engaging a wall of the groove and secured to the rst mentioned element.

6. In a device of moldable material, the combination comprising a Wall having an opening therethrough effected by grooves in opposite side faces of the Wall, entering from different points at the edges of the Wall and having sections overlapping transversely of the plane of the Wall forming the opening through the Wall, an element in one of the grooves at the overlapping section, and a fastener in the other of said grooves securing the iirst mentioned element in position in the groove.

'7. In a device of moldable material, the combination comprising a Wall having an opening therethrough effected by grooves of different widths in opposite side faces of the Wall, entering from opposite edges of the Wall and having sections intermediate the edges of the Wall overlapping transversely of the plane of the Wall, an element in one of the grooves at the overlapping section, and a fastening element in the other of said grooves securing the rst mentioned element in position in the groove.

ALBERT B. RYPINSKI.