US2687456A

US2687456A - Sapeed controlled contact arrangement

Info

Publication number: US2687456A
Authority: US
Priority date: 1951-06-05
Filing date: 1952-06-14
Publication date: 1954-08-24
Anticipated expiration: 1971-08-24

Description

Aug. 24,- 1954 I A. BUCHMANN 2,687,456 SPEED CONTROLLED CONTACT ARRANGEMENT Filed June 4, 1952 2 Sheets-Sheet l INVENTOR B m/mm! Aug. 24, 1954 A. BUCHMANN spasm CONTROLLED cormcw ARRANGEMENT 2 Sheets-Sheet 2 Filed June 4, 1952 INVENTOR Am! Buc Hm) I; BY

Patented Aug. 24, 1954 UNITED STATES PATENT OFFICE SPEED CONTROLLED CONTACT ARRANGEMENT Albin Buchmann, Soleur to Scintilla Ltd., So

e, Switzerland, assignor leure, Switzerland Application June 4, 1952, Serial No. 291,751

Claims priority, application Switzerland June 5, 1951 16 Claims. (Cl. ZOO-80) of the rotatable member.

The novel features which are considered as characteristic for particular in the appended claims. The invention Fig. 2 is a view of the structure of Fig. l in a different position thereof;

3 is a plan view of the apparatus of Fig. 1; 4 is a side, sectional view of a different embodiment of the structure shown in Fig. 1; and

Fig. 5 is a fragmentary, sectional view of yet another embodiment of the invention.

Referring now to the drawings, there is shown a support having an insulating block 5 mounted thereon. This insulating block has fixedly connected thereto, by means of rivets 8 and 9, the springy, electrically conductive, respectively. As is apparent Fig. Fig

to be regulated illustrated in Fig. 2.

The shaft I may be interconnected with the motor to be regulated in any suitable way so as to rotate at a sped equal or proportional to the speed of the motor. For example, the shaft I may be part of the motor shaft. As is clearly illustrated in the drawings, the shaft l extends that shown in Fig. 1.

In a bore formed in a support l4 there is turnably mounted a shaft I5 having a knurled, manually engageable end If and carrying on its opposite end a cam Iii located against the top side of member I so that by turning of shaft It the cam I3 will adjust the position of stationary contact II. An insulating disc I3 is mounted on the member 3 about the opening I2 thereof, through which the shaft I extends, so as to be located between member 6 and disc 3.

The operation of the above-described structure is as follows:

In the position of rest, the parts assume the position shown in Fig. 2 member 6 keeps contact III in engagement with contact II and keeps insulating disc I3 against disc 3 to maintain the latter in an unbalanced position thereof. When the motor is started, the shaft I rotates and, by centrifugal action, the disc 3 will turn about the axis of pin i from the position shown in Fig. 2 toward that shown in Fig. 1. When the speed of the shaft I has increased to a predetermined value, the disc 3 will have assumed a certain tilted position at which the lowermost point thereof will contact the member I3 along a circle located about the axis of shaft I.

As is apparent from Figs. 1 and 2, the member 6 forms a lever arm. Thus, when the lowermost point of disc 3 moves along the contact circle on member I3, the disc 3 will encounter different counter forces from the lever arm formed by member 6, and these counter forces will be at a minimum when the lowermost point of disc 3 is most distant from contact II, since at this time the lever arm is longest, and when this lowermost point of disc 3 is located nearest to contact II, the lever arm of member 6 is shortest and produces the greatest counter force against the disc 3.

As a result of this construction, the shaft I will increase its speed until the disc 3 assumes a tilted position where the lowermost point thereof moves contact I away from contact I I when this lowermost point is located most distant from contact I I, so as to break the circuit to the motor. However when this lowermost point of disc 3 is nearest to contact I I, it is unable to overcome the counter force of the shortened lever arm and therefore the contact Iii moves back into engagement with contact II, by the springy force of member Ii, to again complete the circuit to the motor. Thus, the above described structure provides a means for making and breaking the engagement of contacts I3 and II at 180 intervals of the turning of the shaft I, and during the rotation of shaft I, at the speed for which the apparatus is set, the arm 6 vibrates at a relatively high frequency to continually make and break the circuit to the motor so as to control the speed of the latter.

The parts I5-I'I are adapted to set the contacts I0 and II to be separated at a predetermined speed of shaft I. Thus, if shaft I5 is in the position shown in Fig. 2 and is turned to move contact II downwardly, as viewed in Fig. 2, it is apparent that the contact I6 and member 6 will be moved downwardlly to locate the free right-hand end of member 6, as viewed in Fig. 2, at a further distance beneath the pin 4, when the apparatus is in its position of rest, than is the case with the position of the parts shown in Fig. 2. Therefore, in order to separate contacts It and II, the disc 3 would have to turn through a greater angle about the axis of pin 4 than is the case with the setting illustrated in Fig. 2,

and since a higher speed of rotation of shaft I is where the resiliency of required to increase the angle through which disc 3 turns about the axis of pin 4, the adjusted speed of the motor would be appreciably increased.

It is therefore apparent that the member 6, and contact It therewith, are movable from an initial position, where the free end of member 6 is directly beneath the disc 3 and maintains the latter normal to the shaft I, as shown in Fig. 2, when the parts are at rest, to another position, controlled by adjustment of contact I I, further away from the pin 4 than the initial position, the member 6 and contact IIltherewith being periodically movable by rotation of shaft I, away from its actual, adjusted rest position located at the initial position or at a predetermined distance from the initial position.

With conventional speed regulators, it is usual that the motor speed will fluctuate in the lower speed ranges so that control at such lower speed ranges is practically non-existent. The disclosed structure is particularly suited for high sensitivity at such lower speed ranges by structures similar to those shown in Figs. 4 and 5. In Fig. 4, the motor shaft I8 and shaft I are interconnected by gearing I9, 23 which causes the shaft I to turn at twice the speed of shaft I8. Thus, even when the motor shaft I8 turns at a relatively low speed, the shaft I is still turning at a speed sufficient to cause an efficient operation of the speed controlled apparatus for making and breaking the engagement between contacts If! and II, this apparatus which is illustrated in Fig. 4 being exactly the same as that described above except for the connection of shaft I8 to shaft I by gears I9 and 20.

It may be desirable in some instances to adjust the ratio between the speeds of shafts I and I8, and for this purpose the structure of Fig. 5 is suitable. As is shown in Fig. 5, the shaft 2 carries a friction wheel 24 of relatively small diameter adapted to be contacted and turned by the friction member 23 having a conical outer face 23 and being formed with an annular groove 23". This member 23 is slidable along shaft I8 while being constrained by a key to rotate therewith, and the position of member 23 is regulated by turning of lever 22 which is pivotally mounted on support 2I and has a free end located in groove 23". Thus, as the member 23 is moved upwardly, as viewed in Fig. 5, the turning speed of shaft I will constantly increase with respect to the turning speed of shaft I8.

It is evident that some means must be provided to maintain friction wheel 24 in contact with member 23 during adjustments of the latter. This means may take any suitable form. For example, the support may be furnished with swivelling means 25 (see Fig. 5) in connection with a bracket 26, such swivelling means being suitably positioned in such a way as to enable shaft I to be urged to approach the motor shaft It by the action of a spring 21, or to diverge from the same, according to whether the friction member 23 is lowered or raised, as the case may be.

In another example, wherein the support is stationary, directly beneath the bearing 2, shaft I may be provided with a universal joint interconnecting the lower portion of shaft I, on which wheel 23 is located, with the remainder of the shaft I.

In the former example, one end of the spring 21 is fixed to a post 29 on the bracket 26 and the other end is attached to a second post 30 on the support, whereas, in the latter example,

made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention t others can by applying current knowledge readily adapt it for meaning and range of equivalence ing claims.

What is claimed as new secured by Letters Patent is:

1. A speed controlled of the follow and. desired to be 3. A speed controlled electrical contact arrangement, comprising, in combination, support means; a pair of contacts mounted on said supproportional to the shaft portion.

5. An arrangement as defined in claim 4 and wherein an adjusting means is operatively conincluding said second to moveithe same, and said contact portion thereof, away from said stationary contact when said shaft portion turns at a speed sufficient to turn said weight means about said second axis through such an angle that said weight means engages said contact member.

, '7. An arrangement as defined in claim 6 and wherein said weight means is in the form of a disc formed with a central aperture through which said shaft portion extends, and being formed with a pair of recesses respectively located on opposite sides of said shaft portion and in opposite faces of said disc.

8. A speed controlled contact arrangement, comprising, in combination, support means; a shaft mounted, for rotation about its own axis, on said support means; elongated springy contact means having a contact portion intermediatethe length thereof, being fixedly connected at one end thereof to said support means, and having an opposite free end portion formed with an opening through which said shaft extends; a stationary contact mounted on said support means, being located on one side of said contact means, and contacting said contact portion thereof to maintain said contact means, against its own resilient force, in a predetermined position; a weight disc formed with an aperture through which said shaft extends, being pivotally mounted on the latter for turning movement about a. pivot axis normal to said shaft axis, being located on said one side of said contact means, and being formed with a pair of recesses respectively located on opposite sides of said shaft and in opposite faces of said weight disc, the latter being located adjacent to said contact means so that upon rotation of said shaft at a predetermined speed said weight disc engages said contact means about a circle having its center in said shaft axis so as to move said contact portion of said contact means from said stationary contact.

9. An arrangement as defined in claim 6 and wherein an adjusting means is operatively connected to said stationary contact for locating the same at a predetermined distance from a plane normal to said axis of said shaft portion and axis.

x 10. An arrangement as defined in claim 9 and wherein said stationary contact is in the form of a springy contact member and wherein said adjusting means comprises a turnable cam located against said stationary contact for adjusting the location thereof.

l1. An arrangement as defined inclaim 6 and wherein a motor shaft is interconnected with said shaft portion by a transmission means for turning said shaft portion at a speed approximately twice that of the motor shaft.

12. An arrangement as defined in claim 6 and wherein a motor shaft is interconnected with said shaft portion by an adjustable transmission means for adjusting the turning speed of the motor shaft to a predetermined fraction of the turning speed of said shaft portion.

13., A speed. controlled contact arrangement, comprising, in combination, support means; a first contact member mounted on said support means for movement in a predetermined direction from an initial position and permanently tending to return to said initial position; a second contact member mounted on said support means also for movement in said predetermined direction and being located in the path of said first contact member and abutting against the same; means for adjusting the position of said second contact member so as to move said first contact member, from said initial position thereof, an adjustable distance in said predetermined direction; a rotatable member rotating at a variable speed; and means actuated by said rotatable member and adapted to move said first contact member periodically in a direction away from its initial position to a position spaced from said initial position by av distance varying and proportional-to the speed of said rotatable member so that said distance increases with an increase in the rotative speed of said rotatable member,

whereby when said distance is greater than the said first contact member from actual distance of its initial position, obtained by ad ustment of said second contact member, said first contact memher will be periodically moved out of contact with said second contact member.

14. A speed controlled contact arrangement as defined inclaim l3 and wherein said first contact member is in the form of an elongated springy element fixedly connected at one end thereof to said support means and having an opposite free end portion formed with an aperture through which said rotatable member extendsv 15.. A speed controlled contact arrangement as defined in claim 14 and wherein said means actuated by said rotatable member is in the form of a disc formed with an aperture through which said rotatable member extends, mounted on said rotatable member for free pivotal movement about an axis normal to the axis of rotation of said rotatable member, and being formed with a pair of recesses respectively located on opposite sides of said rotatable member and in opposite faces of said disc, the latter being located adjacent to said free end portion of said first contact member. r

16. A speed controlled contact arrangement as defined in claim 15 and wherein said second contact member also is in the form of an elongated springy element fixedly connected at one end thereof to said support means, and wherein said means for adjusting the position of said second contact member is in the form of a turnable cam engaging said second contact member at .an intermediate part thereof.

References Cited in the file of this patent UNITED STATES PATENTS