US 2498683 A
Description (OCR text may contain errors)
Feb. 28, 1950 HUBBELL 2,498 683 MAGNETICALLY OPERATED SWITCH Filed Feb. 3, 1945 7! INVENTOR ATTORNEYS,
Patented Feb. 28, 1950 UNITED STATES PATENT OFFICE 2,498,683 MAGNETICALLY OPERATED SWITCH Harvey Hubbell, Long Hill, Conn.
Application February 3, 1945, Serial No. 575,961
1 This invention relates to electrical switches. and has for an object to provide an improved and simplified construction of switch in which there is no direct connection between the movable switch element and the operating means, but the switch is operated magnetically and may or may not be enclosed in a sealed chamber, as desired.
It is also an object to provide such a construction in which the switch operating or control means may be located outside the sealed chamber enclosing the movable and stationary contacts. and the contacts may therefore be sealed and the device used in an explosive atmosphere and with no danger of igniting surrounding objects by arcing incident to make and break of the circult.
With the foregoing and other objects in view I have devised the construction illustrated in the accompanying drawing forming a part or this specification. It is, however, to be understood the device is not limited to the specific details oi construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.
In this drawing:
Fig. 1 is a longitudinal section through the device;
Figs. 2 and are transverse sections substan tially on lines 22 and 33 respective of Fig. 1;.
Fig.4isatoppian view; Figs. 5 and 6 are side elevations of movable switch contacts and the mounting means showing slight modifications;
Fig. '7 is a section of the stationary contact with a movable contact shown in elevation;
Fig. 8 is a similar section showing a slight modification, the stationary contact being in elevation and the movable contact in section, and
Fig. 9 is a plan view showing a modified means for operating the switch.
The switch construction, shown by way or example, comprises a body ll! of glass or other suitable molded insulating material enclosing a chamber H, which may be a sealed chamber if desired, with conductors l2 molded in the glass or other insulating material extending to this chamber and with their inner ends forming or connected with stationary contacts. Means may be provided outside the chamber for connecting lead wires to these conductors, such for example as the usual binding screws l3. Mounted in the chamber l I is a movable contact member it comprising sprlng arms l5 having substantially semispherical ends it to engage the stationary con- 2 tacts and to bridge these contacts to close the circuit. This movable contact member is mounted on a free floating permanent magnet l1 and may be secured thereto by an suitable means. In the construction shown it is connected to a metal strip 18 of conducting material by any suitable means such as the rivets l9, and the ends of this strip as indicated at 20 extend upwardly in notches 2| in the opposite ends of the magnet l1 and are each folded over onto a top wall 22 in this notch forming a shoulder to retain the contact in place. The spring arms is support the magnet and hold it against the top wall 23 of the chamber. To reduce friction against this wall and permit the magnet to turn more freely, the magnet may have a central boss 24 on its top wall engaging the wall 23.
Preferably, the stationary contacts, whether formed by the upper ends of the conductors id or separate contacts connected therewith, are located in surrounding recesses 25 in the bottom wall of the body member i6, and the top surface 26 may be concaved, as shown in Fig. 7, so that the semispherical contacts 3 may seat therein and be held by coaction between the two with the contacts in engagement to keep the circuit closed and prevent ordinary jarring separating them. If desired, the contacts may be reversed,
. as shown in Fig. 8, in which case the upper end iii" of each conductor l2 forming the stationary contacts is rounded or semispherical in shape, and the movable contact 28 is reversed so that the concave side may rest on this rounded end to retain the contacts in engagement. The rounded shape of the contacts H5 or 21 permits the movable contacts to slide more readily to and from the stationary contacts.
The side walls of the body in may be extended above the top wall 23, as indicated at 29, to form a second chamber 36 in which is mounted a control or operating magnet 3|. The two magnets l1 and 3| are preferably rectangular, straight, permanent bar magnets, and may be made of any suitable magnetic material, but preferably of some of the new alloys which will retain a high degree of magnetism for an indefinite period, such for example as alnico. The magnet at is also mounted to rotate in the plane of the magnet and parallel to the plane of the magnet i1, and it is located closely adjacent the upper side of the top wall 23, but. if desired, in order to reduce friction against this wall, it may have a central boss 32 on its under side to engage the wall and space the magnet a short distance therefrom. The top or open side of the chamher 30 is closed by a metal housing -33 which also encloses and protects the sides of the body It and may be secured to the body by turning in the lower edges of the side walls over the lower end of the body. as indicated at 34. Mounted in the top wall 35 of the casing is a bearing sleeve 36 for a rotatable shaft 31 connected to the magnet 3| for turning the magnet. Any suitable means may be provided for turning the shaft and magnet, such for example as a hand knob 33 secured to the shaft, and preferably made of some molded insulating material, such, for example, as bakelite."
Means is provided for retaining the contro magnet 3| in different'angular positions in its plane of rotation. For this purpose an inwardly extending bead 39 is formed on the inner side of the top wall 35, but the head is made in segments as indicated in Fig. 4, with seats or gaps 40 and 4| between them in which may seat the transversely rounded feet 42 of spring arms 43 carried by the magnet and shaft 31 to rotate therewith. As these feet run into these notches or gaps 40 and 4| they will yieldingly retain the control magnet 3| in different positions at 90 degrees to each other. The arms 43 may extend outwardly and upwardly in an inclined position from a substantially U-shaped inverted body portion 44 seated on and embracing the magnet 3| so as to rotate with it. As shown in Fig. 3, although the stationary contacts formed on the upper ends of the conductors l2 are arranged in recesses 25 in diametrically opposite positions, similar recesses 45 are arranged at ninety degrees to these first recesses with no contacts in them to permit the I movable contacts i6 to rest in them when the switch is in the oil or open circuit position, and to yieldingly retain the contacts in this position until operated by shifting the magnet 3|.
In Fig. is shown a slightly modified construction of the lower or floating magnet. In this construction the movable contacts H; are mounted on inwardly bent spring arms 46 of a conductor strip 41 secured to the under side of a bar 48 of insulating material by any suitable means such, for example, as the rivets 49. On the outside of the bar 43 are secured two spaced blocks 50-of magnetic material, as soft iron, or permanent magnets, to cooperate with the control magnet 3| for shifting the contacts l5.
In Fig. 6, instead of using the intermediate bar 48 of insulating material, the magnetic blocks of soft iron or magnets 50 are mounted directly on the conductor strip 41.
In Fig. 9 is shown a slightly different means for operating the control magnet 3| for controlling the switch. In this case, mounted on the shaft 31 is a small gear 5| meshing with a segment gear 52 formed with a hand lever 53 pivoted at 54. In this case the casing 33 embracing the body member is provided with a lateral extension 55 having a flange 56 by which the whole device may be mounted in any suitable support, lever 53 operating in a slot 51 in this flange. It will be seen that by swinging the lever 53 back and forth, the gears 52, 5| will turn the control magnet 3| through a quarter revolution to shift it between the off and on positions.
In operation, with the switch in the closed position of Figs. 1 and 2 and the movable contacts I6 engaging the stationary contacts at the inner end of the conductors l2, the two magnets I1 and 3| are in substantial alignment and in substantial parallel relation in adjacent laterally spaced parallel planes. The fee 42 of the spring arms 43 will be seated in the notches 4| of the bead 33 to retain the magnet 3| in this position. As the north and south poles of the control magnet 3| are adjacent the opposite or unlike south and north poles, respectively, of the free floating magnet ll, they will attract each other and the magnet II will be held in the parallel relation to magnet 3|. If now the control magnet 3| is rotated in the plane of this magnet by the operating means, such as the knob 38 or the hand lever 53, the floating magnet II will turn with it in its plane parallel to the plane of the magnet 3|, as the north and south or unlike poles, being adjacent, attract each other. If the magnet 3| is turned ninety degrees to the position of Figs. 1 and 2, the magnet II will follow with it, shifting the movable contacts l6 from the stationary contacts to the recesses 45, Fig. 3, thus opening the circuit. During this movement the spring arms 43 move with the magnet 3| along the top of the bead 39 and in this new or intermediate position the'feet 42 will seat in the notches 40, retaining the magnet 3| in this position, and the switch in the open position. To close the switch again, magnet 3| is merely turned ninety degrees in either direction to bring it to the position of Fig. 1, causing the magnet to follow with it and bring the movable contacts l3 into engagement with the stationary contacts, or with the operating means of Fig. 9 the lever is merely swung in the opposite direction. As shown more clearly in Fig. 1, the spring arms |5 of the movable contact may cross or be extended beyond each other so that each contact i6 engages the stationary contact nearest the opposite end of the bar II. This permits the use of a longer spring arm giving a more yielding and flexible arm.
It will be seen from Figs. '7 and 8 that the cooperation of the concave stationary contact 28 with the convex contact I6 carried on the spring arms |5 will yieldingly hold them in engagement against accidental separation, supplementing the action between the two magnets l1 and 3|. In the form of Fig. 8, the rounded end 21 of the stationary contacts, seating in the concave side of the movable contact 28, will have the same effect.
In the forms of Figs. 5 and 6 the magnetic soft iron blocks 50, or if they are made of permanent magnets, will follow the control magnet 3| the same as will the form of the device shown in Figs. 1 and 2, but if the magnetic elements connected with the movable contacts are permanent magnets, as indicated in Fig. 1, there is greater mutual attraction between them and the control magnet;
giving more positive operation.
It will be seen from the above that this makes a very simple construction, involving a minimum number of parts; also that the movable and stationary contacts may if desired be mounted in a sealed chamber so that they are cut off from surrounding atmospheres, permitting use of this switch with perfect safety in explosive atmos-. pheres and also preventing any possibility of igniting adjacent elements, and the switch may be operated by a control member located entirely outside the sealed chamber with no mechanical connection between them.
Throughout the specification and claims the term magnetic material is used in a generic sense to indicate a material which is affected by magnetic action whether it is suiflciently hard or retains sufl'lcient magnetism so that the member made of it is itself a permanent magnet, or it is soft iron or some other material which is affected by another magnet but itself does not retain sufficient magnetism so that the member made of it would be called a magnet when not under the influence of the other magnet.
Having thus set forth the nature of my invention what I claim is:
1. An electric switch comprising a body member of insulating material enclosing a chamber, a pair of permanent bar magnets located one on each of the opposite sides of the upper end wall of the chamber adjacent thereto and adapted to rotate in planes substantially parallel to said wall, a contact connected to said inner magnet and including spring fingers located under the magnet to support it and provided with contacts on the lower'end wall of the chamber, stationary contacts in said latter wall-arranged to be bridged by said movable contact, and means for rotating the outer magnet to cause the inner magnet to move with it by mutual attraction between the magnets to shift the movable contact.
'2. An electric switch comprising a permanent bar magnet mounted to turn in the plane of the magnet, a free floating element of magnetic material located adjacent the magnet and adapted to turn in a plane substantially parallel with the magnet, a body provided with a chamber in which said element is located, a movable contact connected with said element to move therewith and including yieldable spring contact fingers engaging a wall of the chamber to support and position the element, a stationary contact toward and from which the first contact moves, and means for turning the magnet to shift the element by mutual magnetic action between them to shift the movable contact.
3. An electric switch comprising cooperating stationary and movable contacts, a control magnet comprising astraight bar mounted to turn in the plane of the magnet, a member of magnetic material connected to the movable contact, said member an contact being enclosed in a chamber and free floating so as to be movable in a direction normal to the plane of the magnet and free to turn in a plane adJacent and parallel to the plane of the magnet, and means for rotating the magnet to cause the member and contact to turn with it.
4. An electric switch comprising a body of insulating material enclosing a chamber, a bar of magnetic material located in the chamber adjacent one end wall of the chamber and free floating in the chamber so that it may move in a direction normal to the wall and rotate in a plane parallel to said end wall, stationary and movable contacts in the chamber, said movable contact being connected with said bar to move therewith, a magnet located on the opposite side of said end wall adjacent thereto and mounted to turn in a plane parallel therewith, and means for turning the magnet to cause said bar to turn with it by mutual magnetic action between the bar and magnet to shift the movable contact.
5. An electric switch comprising a body of insulating material enclosing a chamber provided with an end wall, a pair of bars of magnetic material mounted one on each of the opposite sides of said wall to rotate in adjacent planes substantially parallel therewith, one of said bars being a permanent magnet, the inner bar being free floating in the chamber, cooperating stationary and movable contacts in the chamber, the stationary contact being mounted on the opposite wall of the chamber from said end wall, the movable contact being a yieldable spring contact connected with the inner bar to move therewith and riding on the second end wall of the chamber, and means for turning the outer bar to cause the inner bar to turn with it by mutual magnetic action between the bars to shift the movable contact.
6. An electric switch comprising a body of insulating material enclosing a chamber, a free floating bar magnet located in the chamber adjacent one end wall thereof and free to rotate in a plane substantially parallel with said wall, cooperating movable and stationary contacts in the chamber with the movable contact connected with said magnet to move therewith and comprising a yieldable spring contact riding on the opposite end wall of the chamber, the stationary contact being mounted on said latter wall, a second bar magnet located adjacent and on the opposite side of said wall to turn in a plane substantially parallel therewith, and means to turn the second magnet to cause the first magnet to move therewith through mutual magnetic action between the magnets to shift the movable contact.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,277,981 Mathers Sept. 3, 1918 1,499,236 McMillan June 24, 1924 1,818,987 Duffy Aug. 18, 1931 1,874,199 Lingo et al. Aug. 30, 1932 1,887,312 Krueger Nov. 8, 1932 1,917,317 Nacey July 11, 1933 2,421,881 Heasty June 10, 1947