US2626681A - Electromagnetic power mechanism - Google Patents

Description

Jan. 27, 1953 ca. H. LELAND ELECTROMAGNETIC PowEE MECHANISM Filed May 18, 1948 INVENTOR.

62 0665 M ZfZfi/VD 23 secured to a shaft 24 rotatably mounted in a frame member 25 on which the solenoid is supported and which is spaced from the rear or inner side of the solenoid. The ratchet wheel is preferably located on the inner side of the frame member and is rotatable about the axis of the armature shaft l6. Secured to the armature shaft for movement therewith is a power transmitting device which includes a supportin'g member 26, on which is mounted a transmitting element here shown as a pawl 27, the pawl being carried by an arm 28 which forms a part of the member 26 and is offset therefrom to support the pawl in the plane of and in operative relation to the ratchet wheel 23. The member 26 is also provided with a second arm 29 with which is connected one end of an expansion spring 36, the other end of which is connected with a fixed support, such as the frame member 25, the arrangement being such that when the magnet is deenergized the spring will move the pawl to and retain the same in its normal or idle position as shown in Fig. 6. When the armature and shaft are rotated by the energization of the magnet the pawl 27 is moved in a reverse direction with relation to the ratchet wheel and rides over the teeth of the ratchet wheel without imparting movement to the latter. This reverse movement of the member 26 and the pawl 21 extends the spring 33 and thus places the same under tension. At the end of a predetermined reverse movement of the pawl the magnet is automatically deenergized, thereby releasing the armature and the member 26 for rotation in an operative direction by the spring 36, that is in a direction in which the pawl will engage a tooth of the ratchet wheel and rotate the latter. Thus the power generated by the magnet merely retracts the power transmitting element or pawl and places the spring under tension, thereby storing in the spring the power generated by the magnet, and when the transmitting element is released by the deenergization of the magnet this power is utilized to impart operative movement to the transmitting element.

Only a slight axial movement of the armature and shaft is necessary to impart the desired rotation thereto but the pawl supporting member 26 being rigid with the shaft moves axially therewith and to prevent any adverse effect of this axial movement on the power transmitting element the latter has been provided with means to compensate for such axial movement. As here shown the pawl is mounted on a pivot pin 3| rigidly secured to the arm 28 and extending across the plane of the ratchet wheel. The axial movement of the member 26 and arm 28 will cause the pivoted end of the pawl to move laterally with the arm and with relation tothe ratchet wheel. To prevent the displacement of the nose of the pawl with relation to the ratchet wheel by this lateral movement the pivotedend of the pawl is so mounted on the pivot pin 3| that it may have a slight lateral tilting movement, that is the pivoted end of the pawl may move laterally with relation to the nose of the pawl which is in contact wtih the ratchet wheel. For this purpose the opening or hearing in the pawl through which the pivot pin extends is of a diameter slightly greater than the diameter of the pivot pin, as shown in Fig. 9, and the pawl is yieldably retained in its normal position by a coil spring 32 mounted about the outer portion of the pivot pin and bearing against the outer surface of the pawl. Preferably the convolutions 33 of the outer end portion of the coil spring are of such a diam eter that they will firmly grip the pivot pin and retain the spring in position thereon. The com volutions of the spring adjacent the pawl are of a diameter greater than the diameter of the pivot pin and of the bearing in the pawl so that the innermost convolution 34 engages the pawl on all sides of the pivot pin and thus offers resistance to the tilting movement thereof and retains the same normally in its proper position with relation to the ratchet wheel. In the present arrangement the spring 32 also serves to urge the nose of the pawl into engagement with the ratchet wheel and for this purpose the innermost convolution 34 is provided with an end portion 35 which extends over the upper edge of the pawl 21 at a point spaced from the axis thereof and thus constantly urges the nose of the pawl toward the ratchet wheel.

The magnet is energized and deenergized in accordance with the movements of the power transmitting pawlfi'l', and for this purpose a normally closed switch is connected in the magnet circuit and means are provided for opening the same when a predetermined reverse movement has been imparted to the pawl 21 by the magnet and for again closing the switch after the pawl has been actuated by the spring 36. As here shown the switch comprises a fixed contact member 36 mounted on the frame member 25, and a movable contact member 3? carried by a resilient arm 38, that end of the arm opposite the contact member being rigidly mounted on the frame member at 39. A normally stationary switch actuating member is mounted on the frame member 25 and operated by a moving part of the mechanism to open and close the switch. As here shown this switch actuating member is in the nature of a plate 40 pivotally mounted on the bearing 4| in which the shaft 24 is mounted. This member is, of course, formed of fiber or other insulating material and is retained on the hub and its movement frictionally resisted by a spring 42 connected at its end with the frame member 25 and having an opening through which the shaft 24 extends. This switch actuating plate is provided with two arms 43 and 44 which are arranged on opposite sides of a part connected with and moving with the pawl supporting member 26. In the present instance the outer end portion of the pivot pin 3| extends between the arms 43 and 44 and those arms are so spaced that when the member 26 and the power transmitting pawl are in the normal positions shown in Fig. 6 the pivot pin, or the coil spring, will be in engagement with the upper arm 43 of the switch actuating plate, as shown in Fig. 4, and the latter will be retained in that position; and the switch 36-31 will remain closed, until the magnet is energized, the initial energization being effected by a master switch, not shown. Theupper arm 43 is provided with a head 45 which upon the downward movement of the arm 43 will engage the resilient arm 38 which carries the movable contact 31 and move that contact out of engagement with the fixed contact 36. Preferably the arm 38 is provided adjacent the contact 31 with a projection 46 to be engaged by the head 45 of the arm. When the magnet is energized the rotation of the armature moves the power transmitting member in a reverse direction and causes the pin 3| thereof to engage the lower arm 44, thus moving both the arm 44 and the arm 43 downwardly and causing the head 45 to engage the arm 38 and open the switch, the arm 44 being spaced such amen a distance. from the normal position oi the pivot pin 3! that the magnet circuit will be opened when the armature, and therefore, the pawl, has completed 1a. predetermined movement. The opening of the switch, of course, deenergizes the magnet and the spring 30 moves the pawl in power transmitting direction, and as the power transmitting movement of the pawl approaches completion the pivot pin will again engage the upper arm 43 and move the same out of engagement with the resilient arm 38, thereby permitting the switch to close. Inasmuch as the master switch remains closed the closing of the switch 36-'37| will again energize the magnet and another cycle of operations will be effected. This cycle of operations can be and usually is repeated with great rapidity and the power transmitting element will continue to rapidly advance the 'ratchet wheel step by step until the master switch in the magnet circuit is opened.

While I have shown and described one embodiment of my invention I wish it to be understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. In an electromagnetic mechanism, an electromagnet, an axially movable armature for said magnet, means controlled by the axial movement of said armature for imparting rotary movement thereto, a shaft connected with said armature for rotation therewith, a ratchet wheel supported independently of said shaft for rotation about the axis of the latter, a driving member connected with said shaft for rotation therewith, a pawl for said ratchet wheel carried by said member and movable thereby in a reverse direction with relation to said ratchet wheel when said shaft is rotated by said armature, a spring connected with said member to move said pawl in a direction to rotate said ratchet wheel and adapted to be placed under tension by the movement of said member by said armature, and means controlled by said shaft to deenergize said magnet while said spring is under tension and thus release said member for movement by said spring.

2. In an electromagnetic mechanism, an electromagnet, an axially movable armature for said magnet, means controlled by the axial movement of said armature for imparting rotary movement thereto, a shaft connected with said armature for both axial movement and rotary movement therewith, a ratchet wheel mounted for rotation about the axis of said shaft, a member rigid with said shaft, a pawl mounted on said member for engagement with said ratchet wheel and for movement by said member in an inoperative direction when said shaft is rotated by said armature, said pawl being mounted for lateral tilting movement with relation to said member to compensate for the axial movement of said shaft, spring means connected with said member to move said pawl in an operative direction and adapted to be placed under tension by the movement of said member in said inoperative direction, and means controlled by said shaft for deenergizing said magnet when said pawl has been moved a predetermined distance by said armature.

3. In an electromagnetic mechanism, an electromagnet, an axially movable armature for said magnet, means controlled by the axial movement of said armature for imparting rotary 6 movement, thereto, a shaft, connect d with said armature for both axial movement and rotary movement, a ratchet; whe l m unted for. rotation about the axis of said shaft. 9.- m mb r e nn 't d with said shaft for rotation thereby in one direction when Said shaft is rotated by said armature; spring means to rotate said member in the other direction, a pivot pin on said member, a pawl mounted on said pivot pin to engage and actuate said ratchet wheel and having a limited lateral tilting movement with relation to said pivot pin, means to yieldably resist the tilting movement of said pawl, and means controlled by said shaft to deenergize said magnet w n said sha t. has. b en. r tated. a p edete mined distance by said armature.

4. In an l ct ma n ti m chanis an e ecr ma n t. an axially movab e rma ure fo said ma net, m ans ontrolled by th a a mo ement of said armature for imparting rotary movement thereto, a shaft connected with said armature for both axial movement and rotary movement, a ratchet wheel mounted for rotation about the axis of said shaft, a member connected with said shaft for rotation thereby in one direction when said shaft is rotated by said armature, spring means to rotate said member in the other direction, a pivot pin on said member, a pawl mounted on said pivot pin to engage and actuate said ratchet wheel and having a limited lateral tilting movement with relation to said pivot pin, a coil spring mounted about said pivot pin with its inner end in engagement with said pawl, the convolutions adjacent the outer end of said spring being in gripping engagement with said pivot pin and the convolutions adjacent the inner end of said spring being of an internal diameter greater than the diameter of said pivot pin to yieldably resist tilting of said pawl, and means controlled by said shaft to deenergize said magnet when said shaft has been rotated a predetermined distance by said armature.

5. In a device of the character described an electromagnet, an axially movable armature for said magnet, means controlled by the axial movement of said armature for imparting rotary movement thereto, a member connected to said armature for both rotary movement and axial movement thereby, a ratchet wheel rotatable about the axis of said member, a pivot pin carried by said member, a pawl supported on said pivot pin for movement about the latter and for lateral tilting movement with relation thereto, a coil spring mounted on said pivot pin with its innermost convolution in engagement with said pawl, the outer convolutions of said spring gripping said pivot pin, and the inner convolutions of said spring increasing in diameter progressively toward said pawl, means for deenergizing said magnet as said pawl approaches one limit of its movement, and spring means for moving said pawl to the other limit of its movement.

6. In a device of the character described, a ratchet wheel, a rotatable member supported in axial alinement with said ratchet wheel, means for imparting oscillatory movement to said member, a pivot pin on said member, a pawl for said ratchet wheel mounted on said pivot pin for movement about the axis thereof and for limited lateral movement with relation thereto and a coil spring mounted about said pivot pin on the outer side of said pawl, the convolutions ,adjacent the outer end of said spring for gripping engagement with said pivot pin and the convolutions adjacent the inner end of said. spring being of greater diameter than said pivot pin, the innermost convolution engaging said pawl to yieldably resist the lateral movement of the latter and having a part engaging said pawl and urging the same toward said ratchet wheel.

'7. In a device of the character described, a ratchet wheel, a rotatable member supported in axial alinement with said ratchet wheel, means for imparting oscillatory movement to said member, a pivot pin on said member, a pawl for said ratchet wheel mounted on said pivot pin for movement about the axis thereof and for limited lateral movement with relation thereto, a frustro-conical coil spring mounted about said pivot pin with its outer and smaller end portion in gripping engagement with said pin, and with its larger end portion engaging said pawl to yieldably resist the lateral movement thereof, the innermost convolution of said spring having a part engaging said pawl at a point spaced from the axis thereof and urging said pawl toward said ratchet wheel.

- GEORGE H. LELAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,089,280 Loefller Aug. 10, 1937 2,164,976 Whitehead July 4, 1939 2,260,525 Hobbs Oct. 28, 1941 2,340,697 Russell Feb. 1, 1944 FOREIGN PATENTS Number Country 7 Date 826,906 France Jan. 18, 1938 659,975

Germany Apr. 21, 1938

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