US2112235A - Hand brake - Google Patents

Description

P. B. CAMP HAND BRAKE 7 Filed Sept. 28, 1936 March 29, 1938.

5 Sheets-Sheet l P. B. CAMP HAND BRAKE March 29, 1938.

3 Sheets-Sheet 2 Filed Sept. 28, 1956 March 29, 1938. P, BCAMP 2,112,235

HAND BRAKE Filed Sept. 28, 1956 3 Sheets-Sheet 3 Patented Mar. 29, 1938 UNITED STATES FFEQE.

PATENT HAND BRAKE tion of Illinois Application September 28, 1936, Serial No. 102,851

3 Claims.

The invention relates-to the type of hand brake-operating mechanism for railway cars which is attached to a vertical wall of the car and actuated by means of a hand wheel turning on a horizontal axis, the mechanism including a winding drum to which the pull rod of the brake is connected.

The objects of the invention are to provide for an improved control, both automatic and manual, of the operating mechanism.

A desirable embodiment of the invention is fully hereinafter described, and is illustrated in the accompanying drawings, in which Fig. 1 is a vertical central section; of the mechanism taken on the plane of the axis of the winding drum and the shaft of the hand wheel;

Figs. 2 and 3 are views in perspective of parts of the mechanism;

Fig. 4 is a sectional view on the general planes of the line 4-4 of Fig. 1;

Figs. 5 and 6 are similar views, the controlling elements being in different positions; and

Fig. 7 is a sectional view on the line 'l-'! of Fig. 6.

The operating mechanism is, as usual, enclosed in a casing which is to be attached to the end of a railway car, and comprises a back or wall plate Ill, and a cover plate, shown in two sections, the lower section I I being integral with the back plate and enclosing the winding drum and its gear, and the upper portion 12 being detachably secured to the back plate and overlapping the upper margin of the lower section II.

The winding drum l3, to which the pull chain l4, leading to the brake mechanism proper is attached, is journaled upon a shaft I5, supported in the wall plate I0 and the cover. section II. The gear wheel I 6, through which the drum is actuated, is shown as being cast integral with the drum. This gear meshes with and is driven by a pinion I'l, loosely mounted on the shaft l8 of the hand wheel I9, the front face of the hub of this pinion being provided with a series of clutch teeth 20, with which cooperates a sliding clutch element 2| splined upon the shaft IS.

A ratchet wheel 22, cast on the hub of the pinion 11, and located between it and the clutch teeth 20, cooperates with a longitudinally reciprocable pawl 23, for holding the winding drum against turning in releasing direction. The clutch and ratchet mechanisms are controlled by a hand lever 21, journaled in the casing and which occupies the position as illustrated in Figs. 6 and 7 when both of these devices are in release position, and shifts both to engaging positions when moved to the position of Fig. 4, as hereinafter explained. The pawl 23 is advanced by the weight of the controlling lever 2'! into engagement with the ratchet wheel 22, and is held against lateral movement under the backward pressure of the ratchet wheel by an oscillatable abutment 24, journaled on a bearing boss 25 projecting inwardly from the casing wall Ill, and

within which the inner end of the shaft 26 of the control lever 21 is journaled. The abutment 24 is turned to and from operative position (Figs. 4 and 5) and to release position (Fig. 6) by a lug 28 formed on the shaft 26, and engageable with shoulders 29, 30 formed on the hub of the element 24.

The clutch element 2! is controlled by means of a circumferentially channeled spirally disposed fiange 3| carried by a hub 34 mounted upon the shaft 26 and interlocked therewith by means of a lug 32, formed upon such shaft and engageable with a channel 33 in the hub 34. The circumferential channel 35 receives an annular flange 36 on the movable clutch element 2|, whereby the clutch is fully engaged and disengaged by the turning of the shaft 26 through approximately 180 degrees by means of the control lever 21.

A counterweighted lever 3! loosely pivoted on a shaft 38 fixed in the back wall ill of the casing and an instanding web parallel to such wall (Fig. 1) engages by its power end in a pocket in the upper end of the pawl 23, the opposite end 40 of this lever being of sufficient weight to raise the pawl when not under load out of engagement with the ratchet wheel 22. A shoulder 4|, formed on the arm 40 of the lever 3?, projects into the path of a lug 42 on a radial face of the flange 3|, whereby the counterweighted. arm 40 is raised when the clutch elements are in engagement, as in Fig. l, and the pawl 23 is urged downwardly by the lever 37 and is held in this advance position by the weight of the controlling lever 21. As the hand wheel I9 is turned for setting the brake and the pawl 23 clicks over the ratchet teeth, the control lever is caused to vibrate, its weight insuring the re-engagement oi the pawl with the ratchet as it clicks over the teeth thereof.

A spring, as 43, is provided to facilitate a gradual release of the brake when such action is desired and for returning the control lever to its advance position of Fig. 4 after a full releasing operation. This spring, as shown, is in the form of a wire, one end of which is anchored to a post 14- instanding from the cover plate l2 and being located near the left side of the casing. This wire extends upwardly and is curved to the right and thence downwardly past the ratchet wheel, and is continued upwardly to the left thereof, its extreme end being formed into a downturned hook 46, which normally is substantially at the level of the shaft 26. A post or lug 45 projecting from and formed integrally with the web of the clutch control element 3| is so positioned that it comes into engagement with the hook 45 as the control lever is raised and passes the vertical position. (Fig. 5.)

The spring is held in place by lugs 47, 48 and 49 projecting from the inner face of the cover plate l2, and which permit reduction in the size of its loop as the spring is tensioned. The free end of the spring is inclined toward the shaft 26 to insure engagement of the hook 48 by the post 45.

To facilitate the gradual release of the brake, the lever 27 is moved from the position (Fig 4) to which it had been shifted to eifect the engagement of the clutch elements, and to advance the pawl 23, to the position of Fig. 5, where it is retained by the spring as. The hand wheel 19 is manually urged in the direction to tighten the brake to relieve the pressure of the ratchet wheel upon the pawl. The lever 31 is now raised by its counterweighted end and lifts the pawl out of the path of the ratchet teeth. The clutch mechanism remains in engagement, though the ratchet is released. The operator may permit the gradual release of the brake pressure, either partially or completely, and has the use of both hands in controlling this action. If it be desired to maintain a reduced brake pressure, the lever 27' may be returned to the position of Fig. 4, thereby re-engaging the ratchet mechanism. Slight manual movement of the lever to either the right to further tension the spring 13, or left to bring it under the influence of gravity, will insure its automatic return to this position.

The brake may be fully released by throwing the control lever to the position of Figs. 6 and 7, effecting the disengagement of both the clutch and ratchet mechanisms and putting the spring 43 under sufficient tension to promptly restore 'the lever to the position of Fig. 4, thus reengaging the clutch elements and also insuring the reengagement of the pawl with the ratchet wheel. The spring 63 thus simplifies the operation of gradual release and provides for the prompt return of the various parts of the controlling mechanism to full engaging position (Fig. 4).

Various changes may be made in the embodiment of the invention within the scope of the appended claims.

I claim as my invention:

1. In a hand brake operating mechanism, in combination, a hand wheel, a winding drum, gearing for actuating the drum, a clutch for connecting the wheel with the gearing, pawl and ratchet mechanism for holding the drum against releasing movement, a hand lever for controlling the pawl and clutch and arranged to provide for the withdrawal of the pawl in advance of the disengagement of the clutch elements, and for the reengagement of both ratchet and clutch mechanisms on its return to normal position, and a spring for yieldingly arresting the advance of the control lever after the release of the pawl and before the disengagement of the clutch.

2. In a hand brake operating mechanism, in combination, a hand wheel, a winding drum, gearing for actuating the drum, a clutch for connecting the wheel with the gearing, pawl and. ratchet mechanism for holding the drum against releasing movement, a hand lever for controlling the pawl and clutch and arranged to provide for the withdrawal of the pawl in advance of the disengagement of the clutch elements and for the reengagement of both ratchet and clutch mechanisms on its return to normal position, such lever having a range of movement beyond the vertical in each direction, a spring for holding the lever against further advance by gravity immediately after it has passed the vertical, and being sufliciently tensioned by the advance of the lever to clutch disengaging position to cause its return to normal position.

3. In a hand brake operating mechanism, in combination, a casing, a hand wheel, a winding drum, gearing for actuating the drum, a clutch for connecting the wheel with the gearing, pawl and ratchet mechanism for holding the drum against releasing movement, a hand lever for controlling the pawl and clutch and arranged to provide for the withdrawal of the pawl in advance of the disengagement of the clutch elements and for the reengagement of both ratchet and clutch mechanisms on its return to normal position, such lever having a range of movement beyond the vertical in each direction, a spring wire having one end attached to the casing and being looped to enclose the clutch mechanism and the shaft of the control lever and having its free end in hook form and positioned for engagement by a projection from the pivot of the hand lever as the lever is advanced, and to be thereby tensioned to cause the return of the lever to normal position after the release of the clutch.

' PERCY B. CAMP.

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