US1278936A - Centrifugal switch. - Google Patents

Description

JJT. JANETTE, y CEYNTRIFUGAL SWITCH. APPLICATION FILED )ums 16. 1911.

1,278,936. Patented sept. 17,1918.

. few parts which-,may be JOHN T. JANETTE, OF CHICAGO, ILLINOIS.'

CENTRIFUGAL SWITCH.

Application inea June 1s,

To all whom t may, concern.'

Be *it known that I, JOHN T.'JANET1E, a. citizen of the United States, residing at Chi cago, in the county of Cook and State of Illinois, have invented certain new and useful -Improvements in Centrifugal Switches, of which the following i's-a specification.

This .invention relates more particularly to improvementsin switches which are used in connectlon with alternating current mo'- tors for introducing and cuttingout the split phase starting coils or elements.

The objects of this invention are to provide a centrifugal switchv of the character indicated which will be light, ineX ensivein construction, and durable and e cient in operation; to provide a switch of this character which is constructed of comparatively readily assembled; to provide a switch havin an auxiliary contact where thefina-l break 1s madein order to prevent arcing or burningl of the main contact;` and in general, to provide such an 1mproved structure as will appear more fully from the following description. In the accompanying. drawlngs illustrating this invention: y

Figure l is a plan applied to a motor; y

Fig. 2 is a front vjiew of the same;

Fig. 3 is a' fragmentary kview showing the switch open; and,

Fig. 4 is a -sectional view taken onthe line 4 4 of-Fig. 2. .v

The general construction-of single phase alternating current motors having split phase starting coils iswell understood in the art, and is therefore not4 illustrated. In the accompanying drawings, 5 indicates the motor frame and 6' the shaft which engages with a bearing 7 in the frame, these parts. being of any ordinary or preferred form of construction. The centrifugal switch is mounted on the shaft 6 and rotates theref with. This switch comprises 'two rings or disks 8 and 9 which are lnsulated from each other. These disks are engaged respectively by brushes 10 andall which are connected with the circuit leading through the starting coils, so that when a connection is made between these two lringsor disks, the current will be supplied tothe coils. A substantially semi-circular s witch 12 'is pivoted at 13 to the disk 9, and its free end is adapted to engage and make electrical 'connection with `a contact l14, which is connected by view ofthe switch as Spcication of Letters Patent.

l J means of a the wiper 22 Patented Sept. 17, 191.8. l

1917. serial No. 175,158.

pin or rivet 15 with the disk 8.' The contact 14 and rivet 15 are insulated from the disk 9,`as indicated in Fig. 4.

The contact arm or switch arm l2 is urged into contact position by a spring 16, one end of which engages with a shoulder 17 in said arm, the other end being secured in a plate 18 Iwhich is fastened to the disk 9 by means-of rivets 19, or in any other suitable manner. The free end-of the arm 12 is pro-A vided with aslot 20 to receive 21 forlimiting the movement of said end. wiper or auxiliary contact 22 i's pivoted at 23 to a projection on the arm 12. This wiper has a finger 24 which engages withwa hole 25,1n the arm for limiting the movement of said wiper. end of the wiper is curved or shaped, as indicated, at 26 for making wiping .contact with a projection -27 i wardly from the stationary contact 14. An -insulating; plate 28 separates the contact points from the disk 9, and prevents any arcing to ythe disk. The operation-of the switch is as follows: When the motorv swings the arm 12 so that the end thereof is 1n engagement with the contact 14, and thereby closes the circuit from the disk 9 to a guide pin The forwarder free which extends outthe disk 8, and consequently closes the circuit through the starting coils. `When current is supplied to the motor and the speed increases to a predetermined amount, the free end of the arm 12 moves outwardly by the centrifugal force, thereby opening the circuitl through the main switch contacts which are the end of the arm and the 'contact 14. The free end of the wiper 22, however, remains in contact with the lug 27, so that the circuit is not broken until the wiper passes away from such lug. This` wiper is pivoted so that the centrifugal force tends. Ato hold'itsgfree end in engagement, and the positions shown in dotted lines in Fig. 2 indicate .the positions of the parts just previous to thebreaking of the circuit through the auxiliary contact. When the end of the arm 12 reac es the position shown in Fig. 3, has broken the contact with the lug 27, and the spark formed by breaking the circuit will be between the wiper and the lug,'thereby protecting the main switch con-A tacts from injury. When the motor comes to rest, thefsp'ring'l will swing'the free end of the arm 12 back to its original position, the contact rst being made through the iov lcentrifugal switch, the parts of which may `be very readily manufactured, and this switch has proven highly efficient and satisfactory in practice. It will, however, beobserved that changes may be made in the details of construction without departing from the spirit of this invention and therefore, I

do not wish to limit myself to t 'e exact construction or arrangement herein shown or described, except as specified in the following claims, in which I claim:`

l. A centrifugal 'switch for motors, comprising two co-axial contact disks 8 and 9 insulated from each other, a contact 14 connected with the disk S and arranged on the face of the disk 9, a contact arm 12 pivoted at one end to the disk 9 and adapted to make contact with the contact 14, a spring tending to hold said contact arm in engagement with the contact, a lug on said contact, and a wiper pivotally mounted on said contact arm and having limited movement with respect thereto, said arm and wiper being adapti ed to act under the influence of centrifugal force, the arrangement being 'such that the connection will first be broken between the contact arm and the contact 14, and will `finally be broken between the wiper and said In a centrifugal switch, the combination of two contact rings insulated from each other, a contact electrically connected with one of said rings and arranged adjacent to the face of the other ring, a substantially semi-circular switch pivotally mounted at one end on the other ring and having its free end adapted to engage with said contact, a spring tending to hold the switch in engagement with the contact, a projection on said contact, a wiper pivotally mounted on the free end of said switch and having a curved `end for engagement with said projection, an arm on the opposite end of said wiper which engages with a hole in the switchfor limitnig the movement Vof the wiper, the arrangement being such that when the switch is open, the final break will be made between the wiper and the projection. l

3. The combination with a rotatable shaft, of a Contact ring or disk mountedthereon, a second contact ring or disk arranged adjacent to the first-named disk and insulated therefrom, a contact arranged adjacent to said last-named disk and insulated therefrom, an electrical connection betweenl the contact and the rst-named disk, a switch arm pivoted at one end to said second disk with its Jfree end adapted to engage with said contact, a fiat4 spring having one end secured to said second disk and the other end engaging with the opposite end of said switch arm and tending to hold the free end of the switch arm in engagement with the contact, a projection from said contact, and an auxiliary contact pivotally mounted on the free end of said switch arm and havin limited movement with respect thereto,.sai auxiliary contact having a curved terminal for engagement with said projection, the arrangement being such that when the switch opens under the influence of centrifugal force, the iinal break is made between the auxiliary contactvand said projection.

4. In a centrifugal switch, the combination of a relatively fixedcontact, a contact arm which is adapted to be actuated by centrifugal .force t'o open the switch, means tending to hold the contact arm in engagement with the fixed contact, a stop for limiting the-movement of the arm, and an auxiliary contact member coactin with the arm and fixed contact to make t e final break between the arm and the fixed contact when the switch opens.

5. In a centrifugal switch, the combination of a rotatable member, a relatively xed contact mounted on said member, a substantially semi-circular switch arm havingr one end pivoted to the rotatable member on the opposite side of the axis from thel contact, the free end of said arm being adapted to engage with said contact, resilient means for ho ding said arm in engagement with the contact,'said arm having a slot therein, a stop pin for engagement with said slot, and an auxiliary contact member coacting with said arm and said contact, and adapted to make the iinal break when the switch is opened.

-JOHN T. JANETTE.

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