US 700763 A
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Description (OCR text may contain errors)
No. 700,763. Patented May 27, |902.
A. W. HAM.
(Application med occ. 2a, 1901.
V/NESSEE. y Y l www /ar /f/, 74%.., @Md/wf disturbs nor to any appreciable extent tends UNITED STATES PATENT GFEICE.
ALBERT WV. HAM, OF LANSINGBURG, NEV YORK.
SPECIFICATION forming part of Letters Patent No. 700,763, dated May 27, 1902. Application filed 0ctoher 23,1901. Serial No. 79,635. (No model-.l
To C/.ZZ wtont t may concern:
Be it known that I, ALBERT W. HAM, a citizen of the United States, residing in Lansing' burg, in the county of Rensselaer and State of New York, have invented a new and useful Improvement in Trolley-Catchers, of which the following is a specification.
My invention relates to trolley-catching apparatus; and it consists in a novel arrangement of clutching parts which produces great sensitiveness and reliability of action when action is required and is nevertheless unresponsive Linder any conditions except those of emergency, which call for the instant operation of the trolley-catcher. My improvements also are characterized by great simplicity in construction, which enables the trolley-catcher to be made strong and durable and free from liability to disarrangement.
The principle of operation of my improved trolley-catcher I believe to be wholly new. In all the other trolley-catchers with which I am acquainted the working parts depend for operation on centrifugal force, and therefore have to be nicely adjusted, so as to act only when a predetermined maximu m speed of rotation of the trolley-cord reel is attained. In many of these devices springs are relied on to give the required adjustment and to restrain the working parts from operation under all normal conditions. Asis well known, springs do not long retain their initial tension and are liable to changes in condition, especially when exposed to the action of rust or dirt. The working parts of my new trolley-catcher are balanced, so that any uniform speed of rotation of the trolley-reel or any steady increment in rotative speed neither to disturb their normal-arrangement; but a sudden increase of rotative speed of the trolleyreel, such as results when the trolley jumps the wire, is instantly responded to by the catching devices, which stop the further ascent of the trolley instantly. I employ to obtain these desirable results merely the inertia of movable parts and use a light spring only to hold these paris steady in their normal position under normal conditions. This spring performs no such function as do the springs of trolley-catchers heretofore constructed andis under no more tension when the trolley-reel is rotating rapidly and at uniform speed than when the trolley-reel is still.
In the drawings hereto annexed,which illustrate an embodiment of my invention, Figure I is a vertical cross-section of a trolley-catcher, and Fig. 2 is a rear section of the. same with the back plate removed to show the Working parts. Fig. 3 is a view similar to Fig. 2 and shows the clutching parts which embody my invention reduced to a simple and elementary form. Fig. 4 is a view similar to Fig. 2 and shows a variation in the specific application of my invention; and Fig. 5, a view similar to Fig. 2, shows still Vanother specific variation.
These several figures indicate that the principle of controlling the clutch members of a trolley-catcher by the inertia of movable parts may be expressed in many ways without deviating iu the least from the underlying idea. It is, I believe, best to employ some form of device in which the mass of the parts is sufficiently large to manifest considerable inertia on the application of any sudden increment of force, because the sure action of the contrivance will then be less likely to be interi fered with by any accidental impediments, such as the accumulation of rust or dirt. I prefer, therefore, the specific arrangement of parts shown in Figs. l and 2 and will devote the greater part of theffollowing description to that form of trolley-catcher, first, however, alluding to the elementary example shown in Fig. 3, which exhibits the principle of operation by perhaps the simplest structure.
E, Fig. 3, represents a rotating disk or reel, which turns in the direction of the arrow m. At a5 there is a fixed rack, Whose teeth a2 form the stationary member of the clutch. The
vother member of the clutch is a pawl P, loosely pivoted on the pin p.
P is the operating end of the pawl P, and P2 is a projection which balances the pawl evenly on its pivot, so that there is little or no tendency for it to turn on the pivotp under the influence of gravity or centrifugal force. A light spring S holds the pawl P against the stop p', which is fixed on .the disk or reel E. No matter how fast the disk E may revolve, so long as its speed is constant or only slowly increasing, the spring S,'though very `light, will hold the engaging point P out of reach of the rack-teeth a2. Centrifugalforce does not in the least tend to turn the pawl P on its pivotpin p, and it is better that 4it should not, for ifthe pawlP were not well balanced the spring S would have to be stronger than is consistent with sensitivity of the clutch to sudden increments of rotative speed'. If a disk, such as E, were to be rapidly rotated in the direction of the arrow m and then suddenly stopped, the pivoted pawl P would continue to rotatein the same direction, responding to the tangential' couple represented by `the arrows l and 2. Conversely, if the disk Eis suddenly started to rotate in the direction of the arrow mthe inertia of the pawl P, expressed by the tan-V gential couple 3 4, rotates the pawl (relatively to the reel E) in a direction opposite to the arrow m, and the engaging point P/ enters the first tooth-space of the rack 61,5; or, otherwise expressed, the operation is `as follows: When the disk E is suddenly started or is given a sudden increment of speed in the direction of the arrow m, the pivoted pawl P, by reason of inertia, resists deiiection from its previous position and moves directly into the tooth-space first presented to it.
Although the structure shown in Fig. 3 is entirely operative, it is, for reasons above stated, desirable to employ a clutch member of greater mass than that of the pawl P, Fig. 3, and I therefore prefer the device shown in Figs. l and 2. i
The cylindrical dashboard-casting A is provided with a front plate D and back plate B, suitably flanged at d and l), respectively, for convenience in attachment to the casting A. At the back of the casting A and diametri@- ally across the same there is provided a groove a, which registers with an aperture in the ange ofthe back plate B and affords the means for attaching the trolley-catcher to the dashboard of the car in the usual manner. A spindle ct', secured to or integral with the casting A, projects forward to the front plate D, to which it is secured by the screw CL3. The spindle ct serves as a bearing for the trolley-cord reel E. Back of the space occupied by the trolley-cord reel E there is provided a shallow cylindrical depression a4, of which the side walls a5 are provided with internal rack-teeth a2. A hollow hub e,- secured to or integral with the reel E, fits and turns upon the rear portion of the spindle a; A spring F, coiled within the hollow portion of the reel E,serves to keep the trolley-cord T under constant proper tension and to wind in slack as the trolley may descend. In crosssection in Fig. l there is seen the portion C of the clutch member which is carried by the rotative reel E. Theclutch arrangement is, however, better shown in Fig. 2. The clutch consists of two members, the stationary member being the rack a2, the other member being carried by the rotating reel E. This reelcarried clutch member comprisesthe pawl P, pivoted at p upon the back plate of the reel E, and the actuator C, which is connected with the pawl-P by the link p3, the latter being pivoted to the pawl and actuator at p2 and p", respectively. The actuator C is'pivotally hung upon the hub c, so as to turn freely and loosely` thereon when obliged to do so. A light spring S, secured to the actuator C at .s and to the reel E at s', serves to hold the reelcarried clutch member in position with the pawl P resting against the stop p. The pawl P is so proportioned that the ends P P2 substantiallybalance each other, and likewise' the actuator C is symmetrically balanced upon the reel-hub e. The trolley-cord T, as shown at Fig. 2,'emerges from the casting A through the hub as, which is suitably secured to or cast integralfwith the cylindrical shell portion of the casting A. In operation while the reel E is stationary or is rotating with only a gradual increment of speed the light spring S holds the reel-carried clutch member stationary with relation to the reel; but if a sudden increment of speedis imparted to the reel E, as by the trolley jumping from the trolley-wire,the yielding tension of the spring S, between the reel-carried clutch member and reel, -permits the inertia of the clutch member to assertitself and to move the clutch member with relation to thereel, and thus to advance the engaging point P of the pawl P into clutch with the teeth a2 ofthe rack. This of course stops the reel at once, and the trolley, if it has left vthe .trolley-wire, is restrained fromrising to adangerous height. In practice this clutch apparatus is so sensitive and prompt in action vthat the trolley itself cannot rise far from the wire or do any damage whatever to 4the trolley-wire supports. In many cases the impact which causes the trolley to jump from the wire depresses the trolley so far that its return is checked by the trolley-catcher above described before the trolley rises any higher than the wire itself. The advantage of my inertia trolley-catcher lies largely in the fact that it never tends to act while normal conditions are maintained, but revolves with the reel almost as an integral part thereof. When, however, a sudden jerk of the trolley calls for the instant action Y of the trolley-catcher, the inertia-controlled clutch mechanism acts at once. The location of the actuator C is such thatit can be given considerable mass, and thus it reinforces the lighter mass of the pawl P and actuates it in IOO IIO
case of emergency with more promptness and equivalent to the elementary structure (shown in Fig. 3) and also to the preferred structure. (Shown in Figs. l and`2.) In Fig. 4, for instance, I show the actuator C as provided With a pivot p, upon which is carried the pawl P. The hub c is provided with spring-anchorage s', and the spring S', secured therein, loosely engages the actuator at s. A stop P3 is fixed to the reel E, and the spring S, acting upon the pawl P, holds the same normally against the stop p', which is mounted on the actuator C. With this arrangement, again, under normal conditions the spring S retains the reel-carried clutch member substantially stationary with relation to the reel; but when the reel suddenly lstarts to rotate and the inertia of the actuator C causes the same to lag behind the reel for an instant the pin P3 strikes ,against the inclined edge of the pawl P and forces the engaging end P into a toothspace in the rack c2. In Fig. 5 the pawl P is mounted in a slide or groove p5, cut for the purpose in the back wall of the reel E. The gaging end P of the pawl P normally passes close to the ends of the rack-teeth a2 as the reel E revolves. The pawl P is provided with a base p6, the latter being perforated at 197 to receive the pin c, which is secured to or integral with the actuator C, which, as in the previous cases, is pivotallyhung at the center of the reel E. The spring S, secured to the actuator at s and to the reel at SQ normally holds the reel-carried clutch member in contact with the stop p, which in this case is the end wall of the slot or groove p5. A stop-pin e serves to reinforce the pawl P and to sustain the shock of stopping the reel. When a sudden increment of speed is given to the reel E, the inertia of the reel-carried clutch member causes the pawl Pto move toward the circumference of the reel and into engagement with the teeth in the rack CL2.
W'hat I claim, and desire to secure by Letters Patent, is L l. The combination of a reel, its windingspring, a clutch, whereof one member is stationary, the other carried by the reel and loosely mounted thereon, in such manner that the inertia of the said reel-carried clutch member moves it in to clutch with the stationary clutch member when the rotative speed of the reel is suddenly increased.
2. The combination of a reel, ilswindingspring, a clutch, whereof one member is stationary, the other carried by the reel and loosely mounted thereon, in such manner that the inertia of the said reel-carried clutch member moves it into clutch with the stationary clutch member when the rotative speed of the reel is suddenly increased, and a yielding connection between the reel and the clutch member carried thereby.
3. In a trolley-catcher, the combination with areel mounted on a fixed support, a winding-spring for the reel, a clutch, whereof one member is stationary and the other member is movably mounted on the reel and comprises a loosely-mounted clutch-actuator,the clutchactuator a yielding connection between the said actuator and the reel, the several parts arranged so that the inertia of the clutch-actuator changes the relative positions of the actuator and reel when the rotative speed of the reel is suddenlyincreased, and moves the clutch members together.
4. In a trolley catcher, the combination with a reel, mounted on a fixed support, a
winding-spring for the reel, a clutch, whereof one member is stationary, and the other member is movably mounted on the reel and comprises a clutch-actuator, the clutch-actuator,
consisting of a piece loosely mounted on the reel, a yielding connection between the acnection between the actuator and the reel,
the several parts so arranged that the inertia of the clutch-actuator changes the relative positions of the actuator and the reel and moves the clutch members together when the rotative speed of the reel is suddenly in'- creased.
6. The combination, in a trolley-catcher, of the reel, winding-spring, stationary support, rack thereon, pawl mounted on the reel and connected to an inertia-controlled pawl-actuator, the said pawl-actuator, consisting of a bar loosely mounted on a hub attached to and concentric with the reel, and a spring connecting the reel and actuator-banwhereby the pawl is normally held clear of the rack, substantially as described.
7. The combination of a reel, its windingspring, a clutch, whereof one member is stationary, the other carried by the reel, loosely mounted thereon, and balanced With respect to centrifugal force, in such manner that the inertia of the said reel-carried clutch member moves it into clutch with the stationary clutch member when-the rotative speed of the reel is suddenly increased.
8. The combination of a reel, its windingspring, a clutch, whereof one member is stationary, the other carried by the reel, loosely mounted thereon, and balanced with respect to centrifugal force, in such manner that the inertia of the said reel-carried clutch member moves it into clutchvwith the stationary clutch member when the rotative speed of the reel is suddenly increased, and a yielding connection between the reel and. the clutch member carried thereby.
9. In a trolley-catcher, the combination with a reel mounted on a fixed support, a winding-spring for the reel, a clutch, whereof one member is stationary, andthe other member is movably mounted on the reel in balance with respect to centrifugal force, and
comprises a loosely-mounted clutch-actuator, the clutch-actuator, a yielding connection between the said actuator and the reel, the several parts arranged so that the inertia of the clutch-actuator changes the relative positions of the actuator and reel when the rotative speed of the reel is suddenly increased, and moves the clutch members together.
10. In a trolley-catcher, the combination with a reel mounted on a iixed support, a Winding-spring for the reel, a clutch, whereof one member is stationary and the other member is movably mounted on the reel and comprises a clutch-actuator, the clutch-actuator, consisting of a piece loosely mounted concen- ALBERT W. HAM.
.FRANCIS J; MoLLoY,
GEO. F. MARKHAM.