US2318740A - Speed responsive device - Google Patents

Description

May 11, 1943. 11.1. BONE SPEED RESPONSIVE DEVICE Filed April 8, 1942A 2 Sheets-Sheet l May 1l, 1943. H. L BONE SPEED RESPONSIVE DEVICE Filed April 8, 1942 2 Sheets-Sheet 2 H15 Afro/wmf Patented May 11, 1943 SPEED RESPONSIVE DEVICE Herbert L. Bone, Forest Hills, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application April 8, 1942, Serial No. 438,107

8 Claims.

My invention relates to speed responsive devices, and particularly to governors which are adapted for use on trains in connection with automatic train control equipment to limit the speed at which the trains may operate under certain conditions.

One object of my invention is to provide a governor of the type described in which the effect of centrifugal force on the contact parts is reduced to a minimum.

Another object of my invention is to provide Va. governor of the type described in which the contact opens and closes with a reliable snap action.

Governors embodying my invention are an improvement upon those described and claimed in Letters Patent of the United States No. 2,113,645 granted to me on April 12, 1938.

According to one form of my invention, a pair of interconnected centrifuge members are pivotally mounted on a supporting member which is rotated at a speed which is proportional to the speed of the vehicle or other device with which the governor is connected. The centrifuge members are disposed for swinging movement toward and away from the axis of rotation of the supporting member to in and out positions,

vand are biased to their in positions by spring link assemblies arranged to provide va limited toggle action which causes the centrifuge members to swing all the way from either extreme position to the other when they start to move. A

contact finger is attached at one end to the one centrifuge member and is provided at the other end with a low resistance contact button which cooperates with a similar button mounted on a fixed arm secured to a slip ring forming part of the supporting member. For the purpose of eliminating the effect of centrifugal force on the contact nger, the finger is secured to the associated centrifuge member in such a position that it is disposed substantially on the radial line extending from the axis of rotation of the centrifuge member through the axis of rotation of the supporting member, and the contact button carried thereby is disposed substantially at the axis of rotation of the centrifuge assembly. Ex-

.temal connections with the contact members are made through the medium of said slip ring and ,another slip ring which is electrically connected with said contact nger and which is insulated from said first mentioned slip ring.

According to another form of my invention the centrifuge members are biased to .their in po,- sitions ,by springs which apply a force toi the members along a line extending parallel to the line passing through their pivots; and the centrifuge members each have their center of gravity disposedon a line located closer to the axis of rotation of the governor than a line normal to the line passing through the pivots, whereby the centrifugal moment exerted on the members increases rapidly as they move from their in" to their out positions.

vOther objects and characteristic features of my invention will become apparent as the description proceeds.

I shall describe two forms of speed responsive devices embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is an end view showing one form of governor embodying my invention. Fig. 2 is a side view of the governor shown in Fig. 1 as it appears when viewed kfrom the right in Fig. 1, with some of the parts broken away or sectioned to better illustrate the construction of the remaining parts. Fig. 3 is an isometric view of one of the centrifuge members forming part of the governor shown in the preceding views. Fig. 4 is a view similar to Fig. 1 showing a modification of vthe governor illustrated in Fig. 1.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1 to 3, inclusive, the device in the form here shown comprises a head made up of two annularconducting members i and 2 clamped by means of bolts 3 to the opposite sides of an insulating plate 4, which plate, in turn, is secured by means of bolts 5 to a flange 6 formed on one end of a drive shaft 1. The drive shaft 1 is operatively connected with the device to the speeds of which it is desired to have the governor respond, and when this device is a railway vehicle, the drive shaft may be connected with one of the vehicle axles by means of drive mechanism similar to that shown and described in an application for Letters Patent of the United States, Serial No. 373,132, filed by myself and 'another on January 4, 1941, for Generator and mounting means therefor. As will appear hereinafter, the outer surfaces of the annular conducting members I and 2 serve as slip rings, and

washers 8. y vMountedvin hushed bearingslj and Ii provided in the member 2 at the opposite ends of the'base of an isosceles triangle the apex of which is disposed at the axis of rotation of the governor head are two pivot pins I2 and I3 which pivotally support two centrifuge members I #l and I (see the pivot pin I3 shown in Fig. 2). These centrifuge members as here shown are each in the form of a crank, and each is provided with a straight arm (ifa, Ia) and with a weight armV so disposed that the center of gravity of the weight arm is located on a line extending through the pivotal axis of the member at right angles to the longitudinal axis of the straight arm. The

ends of the straight arms Illa and I5/ia are conl nected together by a toothed connection IB which' constrains the two centrifuge members to operate in unison, and the parts are so proportioned that gravitational and vibrational forces will balance out.

Associated with each centrifuge member is a V recess formed in the weight arm of the associated centrifuge member, whereby thespring rods are rendered self aligning in all directions with respect to the associated weight arm. Each spring link assembly also comprises a compressed coil spring 26 which bears at one end against an v annular flange 2l provided on the headed end of the associated spring rod, and at the other end against an annular shoulder 28 provided on the associated guide 22.

The centrifuge members operate a contact comprising two cooperating contact buttons 30 and 3l. The contact button 30 is secured to a rigid arm 32 formed on the annular member I, whereby this contact butto-n is electrically connected with the annular member I. The other contact button `3| (see Fig. 3) is secured 4to a flexible contact finger 33 attached by means of an angle bracket Y34 to the weight arm |417l of the centrifuge member I4, which latter is electrically connected with the annular member 2 by means of a flexible connector 35. As was pointed out hereinbefore, the outer lsurfaces of the annular members I and 2 serve as slip rings, and it will be seen, therefore, that external electrical connections with the governor contact may bev readily made by providing suitable brushes (not shown) which bear against the slip rings.

The free end of the contact linger 33 is bent to form a U-shaped return bend 33a which extends between bifurcations I4c `(see Fig. '3) provided on a rigid finger 14d formed on the weight arm Mb of the centrifuge member I4. The finger 33 is biased by its own resiliency to such a position that it will swing clear of the nger Md to the extent permitted by the returnbend when the centrifuge members swing outwardly under the action of centrifugal force, and it will be seen, therefore, that the return. bend 3Sa. acts as a stop to limit the motion of the finger when the The motion of the centrifuge members away from the axis of rotation of the governor head under the action of centrifugal force is limited by stop screws 3E mounted in the lugs Z3. The stop screws are adjustable and are arranged to be locked in their adjusted positions by jam nuts 35.

For convenience I shall hereinafter refer to the positions of the centrifuge members to which they are biased by the toggle link assemblies as in positions and the opposite positions as ou positions.

The spring link assemblies are so positioned that when the weight arms occupy their in positions-the force applied by each spring link assembly will be applied along a line which makes an obtuse angle with the line on which the center of gravity of the weight arm is located. With the spring link assemblies arranged in this manner, when the centrifuge members swing outwardly, a limited toggle action takes place which causes the resultant spring force applied to the centrifuge members to decrease, whereby when the critical speed is reached at which the centrifuge members start to move from their in t0 their out positions, they will move all rofthe way with a snap action without further change in speed. Similarly, when the critical speed is reached at which the centrifuge members start to move from their out to their in positions, they will move all of the way to their in positions with asnap action. It will be apparent,- of course, that the obtuse angle formed between the1ine of force of the spring link assembly and the line extending through the axis of rotationrof Vthe centrifuge members and on which the center of gravity is located should never be great enough to cause the resulting toggle to reach its dead centerl position when the centrifuge members Iare swung to their out positions.

It is desirable in a governor of the type de.- scribed to be able to cause the governor to respond to any critical speed within a wide range of speeds, such for example, as a range between and 100 miles per hour,Y merely by selecting springs 26 having different characteristics. 4To be ablerto accomplish this result, it is 'necessary to Yeliminate any effect of centrifugal force on the contact parts, and in accordance with my present invention I accomplish this result by disposing the flexible contact finger 33 so that it lies substantially on the radial line extending between the axis of rotation of the governor head and the axis of rotation of the associated centrifuge member, and I attach the contact button 3l to this finger in such a position that it is disposed substantially at the axis of rotation ofY the governor head- This arrangement eliminates any necessity for'changing the tension of the 4,contact spring when the springs 2li are changed to cause the governor to operate at different speeds.

The operation, as a whole, of the governor will be apparent from an inspection` of the drawing and from thel foregoingdescription without .the necessity for further detailed description, i't ibeing obvious that the contact Sil-,3| will be 'opened or closed according as `the centrifuge members Hand I5 occupy their out yor their in posi*- j'tions, and that when the contact opens or closes,

to their out positions, the contact Sil-3l will not open until the arm Mb has moved far enough to cause the finger IlcL to engage the return bend 33a. This construction insures that the contact will not open in response to slight movements of the centrifuge members caused by vibration, or while the contact members are in their unstable conditions which they occupy when the governor is operating at very close to thecritical speed and thereby avoids chattering of the. contacts.

Referring now to Fig. 5, the governor here shown differs from that shown in the preceding view in the construction by virtue of which snap action of the contacts is obtained. AsA here shown, the centrifuge members which are here designated 50 and 5I are so constructed that their centers of gravity, instead of being located on lines extending through the pivots at right angles to the straight arms, as is the case with the centrifuge members I4 and I5 shown in Figs. 1 and 2, are located on lines drawn through the pivots closer to the axis of rotation of the governor than the first mentioned lines. In other words, the center of gravity of the centrifuge member 50 instead `of being located on dash line T is located on dash line TI.

Furthermore, as here shown, the centrifuge members are biased to their in positions by compression springs 52 and 53 positioned at thei:` outer ends by spring guides 54 and 55 screwed through threaded openings in the lugs 23, and held in place at their inner ends by spring guides 56 and 51 provided on the centrifuge members 50 and 5I, respectively. The springs are so disposed that the lines of the spring forces extend substantially parallel to the linedrawn through the pivots. The remainder of the governor shown in Fig. 5 is similar in all respects to the governor shown inv Figs. 1 and 2.

`'Ihe object of this modified construction is to provide av considerably increased centrifugal moment when the centrifuge members move from their in to their out positions without the necessity for resorting to spring link assemblies of the-toggle type suchas those shown in Fig. 1. For example, the moment arm of the .centrifugal force acting on the centrifuge member" 5B `when this member occupies its in position is distanceY which is at right angles to a line drawn between the center of rotation oi' the centrifuge assembly and the center of grav- `ity Z of the centrifuge member 50. The centrifugal moment is the centrifugal force acting at Z times its moment arm Y. When the centrifuge members move out under the action of centrifugal force, the center of gravity of centrifuge member 50 moves to a point ZI which gives a moment arm YI which it will be noted is considerably larger than the moment arm Y. There isalso some'a'ctual increase in the value of the centrifugal force because the radial distance of the center of gravity from the center of rotation has also increased. By proper proportioning of the parts the increase in centrifugal moment as the centrifuge members move out can be made considerably greater than the increase in the spring force exerted by the springs 52 and 53, and therefore a snap action of the contact can be obtained.

This arrangement has the disadvantage that it is affected slightly by gravity and vibration because the center of gravity is not located so that these forces will balance out. However, it

can be satisfactorily employed in high speed governors because the effects of gravity'and'vibration at high speeds are small compared with the centrifugal force.

y Although I have herein shown and described only two forms of speed responsive devices embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A speed responsive device comprising a rotatable supporting element, a centrifuge member pivotally supported on said supporting element for movement toward and away from the axis ofrotation of said supporting element, and a contact finger secured to said centrifuge member and carrying a contact button which cooperates with a fixed contact button mounted on said supporting element to form a contact, said contact finger being disposed substantially on the radial line extending from the axis of rotation of said supporting element to the pivotal axis of said centrifuge member and the button carriedby said finger being disposed substantially at the axis of rotation of said supporting element to eliminate the effect of centrifugal force on the contact parts.

2. A governor comprising a centrifuge member pivotally mounted on a rotatable supporting element, and contact mechanism operated by'said centrifuge member and comprising a contact spring secured to the centrifuge member and disposed substantially on the radial line extending from the axis of rotation of said supporting member through the pivotal axis of said centrifuge member, said contact spring being provided with a contact button disposed substantially at the axis of rotation of the supporting member and cooperating with a fixed contact button mounted on the supporting member.

3. A governor comprising a rotatable supporting member, two centrifuge members pivotally mounted on said supporting member at the .opposite ends of the base of an isosceles triangle the apex of which is disposed at the axis of rotation of said supporting member, each said centrifuge member comprising a straight arm and a weight arm having a center of gravity disposed on a line extending through the pivot substantially at right angles to the straight arm, said weight arms being movable toward and away from the axis of rotation of the supporting member to in and ou positions and said straight arms being interconnected to cause the two centrifuge members to operate in unison, the parts being so proportioned that gravitational and vibrational forces balance out, two spring link assem- -blies one operatively connected with each weight arm for biasing the weight arms to their in positions, said links assemblies being disposed to apply a force to the weight arms along a line extending at an obtuse angle to the line on which the center of gravity is located, whereby a limited toggle action is provided which causes the weight arms to swing between their in and out positions with a snap action, a contact finger secured to one weight arm and disposed substantially on the radial line extending from the axis of rotation of said supporting member through the pivotal axis of the associated centrifuge member, and a contact button secured to said finger substantially at the axis of rotation of the supporting member and cooperating with a fixed contact element mounted on the supporting member to form a contact.

4. A governor comprising an insulating'plate secured to a driving member, two annular conducting members secured to said insulating plate, a spring biased centrifuge member pivotally attached to the one annular conducting member and provided with a contact finger disposed substantially on the radial line extending from the axis of rotation of said plate through the pivotal axis of said centrifuge member, said nger Abeing electrically connected With the one annular conducting member, and a contact button secured to said nger substantially at the axis of rotation of said plate and cooperating withl a iixed contact button mounted on a rigid arm formed on the other annular member, said two annular members serving as slip rings to facilitate making external electrical connection `with'the contact formed by said two contact buttons.

5. A governor comprising a centrifuge member pivotally mounted on rotatable supporting means, said centrifuge member being movable to in and out positions and being biased to its in position in such manner that it will move between its in and fout positions with a snap action, a contact finger secured to said centrifuge member and disposed substantially on the radial line extending from the axis of rotation of. said supporting means through the pivotal axis of said centrifuge member, a contact button secured to said finger substantially at the axis of rotation of said supporting means and cooperating with a fixed contact button mounted on the supporting means to form a contact, a rigid finger formed on said centrifuge member and cooperating with said contact finger at the side opposite to the contact button to determine the in position of the centrifuge member, said rigid linger being provided with a bifurcated end and said contact ringer being provided with a return bend which extends between the bifurcations on `said rigid finger, said contact finger being biased away from said rigid finger by .its ownresiliency to a position determined by said return bend. L i

6. A governor comprising a rotatable supporting means, two centrifuge members pivotally sup'- poi'ted on said supporting means at the opposite ends of the base of an isosceles triangle the 'apex of which is disposed at the axis of rotation of said supporting means, each said centrifuge member comprising a straight arm and a weight arm, said vstraight arms being connected together to cause the centrifuge members to operate in unison, said weight arms being movable toward and away from the axis of rotation of said supporting means to in and out positions, spring means associated with the weight arms and efe fective to bias them' to their in positions by a force acting on a line extending substantially parallel to the straight arms, a contact finger secured to one weight arm and disposed Lalong the line extending from the axis of rotation of the supporting means to the pivotal axis of the associated centrifuge members, and a contact button secured to said finger substantially at .the pivotal axis of said supporting means and coop# erating with a xed contact button secured to the supporting means to form a contact, said cen-e trifuge members being so constructed that their centers of gravity are located on lines extending through their pivots closer to the axis of rotation of the supporting means than the lines extending through their pivots at right angles to the straight arms, whereby the centrifugal moment increases as the arms move outwardly to provide a snap action of the contact.

7. A governor comprising a centrifuge member pivotally mounted on a rotatable supporting element and including a weight arm rotatable toward and away from the axis of rotation of said supporting element, a Contact operated by said centrifuge member, and spring means associated with said weight arm and effective to bias said weight arm toward the axis of rotation vof said supporting element by a force acting nor# mal to a line extending through the pivotal axis of said centrifuge member farther from the axis of rotation of said supporting member than the line passing through the center of gravity of said Weight arm and the axis of said centrifuge member, whereby the centrifugal moment increases as the -weight arm moves outwardly to provide a snap action of said contact.

8. A governor comprising a rotatable supporting means, two centrifuge members pivotally supported on said supporting means at the opposite ends of the base of an isosceles triangle the apex of which is disposed at the axis of rotation of said supporting means, each said centrifuge member comprising a straight arm and a weight arm, said straight arms being connected together to cause the centrifuge members to operate in uni son, said weight arms being movable toward and away from the axis'of rotation of said sup# porting means to in and out positions, spring means associated with the Weight arms and effective to Abias them to their in positions by a force acting on a line extending substantially parallel to the straight arms, and a contact op erated by said centrifuge members, said centrifuge members being so constructed that their centers of gravity are located on lines extending through their pivots closer to the axis of rotation of the supporting means than the lines extending through their pivots at right angles to the straight arms, whereby the centrifugal moment increases as the arms move outwardly to provide a snap action of the contact.

HERBERT L. BONE.

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