US2042762A

US2042762A - Pawl release

Info

Publication number: US2042762A
Application number: US21048A
Authority: US
Inventors: Ola L Berby
Original assignee: CLYDE IRON WORKS
Current assignee: CLYDE IRON WORKS
Priority date: 1935-05-11
Filing date: 1935-05-11
Publication date: 1936-06-02
Anticipated expiration: 1953-06-02

Description

June 2, 1936. 0. BERBY I 2,042,762

PAWL RELEASE Filed May 11, 1955 2 Sheets-Sheet 2 Patented June 2, 1936 PATENT OFFICE PAWL RELEASE 01a L. Berby, Duluth, Minn., assignor to Clyde Iron Works, Duluth, Minn., a corporation of Maine Application May 11, 1935, Serial No. 21,048

10 Claims. (0]. 192-2) My invention relates to an improvement in pawl release, wherein it is'desired to provide a means of releasing a pawl or dog which has been in engagement with a rotating member to prevent rotation in one direction against the pawl engagement.

I have shown my release in its application to an antenna winch often requiring power to lower as well as raise the load. Obviously, my release is applicable to all types of rotative members which are driven in one direction and which use a pawl or dog to lock the member against rotation in this one direction.

It is a feature of my invention to provide a simple mechanical means for releasing a pawl or dog from engagement with a rotatable member. This release is operated by a manually operated lever and acts in co-operation with a control for the driving means of the rotatable'member in such a manner that the pawl is entirely released before power can be applied to rotate the rotatable member against the pawl or dog. The simplicity of the device, and the small number of parts necessary to accomplish the desired result, add to the eiiectiveness and desirability of the release of my construction.

In hoisting devices, such as for example the winch illustrated, a positive lock such as a pawl is extremely desirable particularly where a load is to be suspended for any length of time. 'Where the load being hoisted is always sufficient to move thedrum in one direction, a motor which moves the drum in but one direction is necessary. Where the load is not always sufiicient'to unwind the cable drum, a reversible driving means isnecessary. The use of a positive lock with a reversible driving means is dangerous and undesirable unlessa safety device is provided for ascertaining that the positive lock is released before the power is applied to lower the load.

Costly electrically operated releasing means have been designed; but such means are disadvantageous due not only to their prohibitive cost but also because all such appliances must be water and weather proof, necessitating bulky packings and casings. My simple mechanical release is as positive in its operation, and as durable as the remainder of the hoist, and embodies no parts which are apt to wear out in use.

It is a feature of invention to provide a means which not only prevents operation of the controller of the driving means to drive the rotatable means in one direction when the rotatable means is locked against such rotation, but also which holds the locking means from engagement -with the rotatable member while the controller is in position to drive the rotatable member in that direction. The pawl which engages the ratchet gear on the drum cannot be engaged at the time the controller is actuated to drive the drum against the pawl; and once the controller has been operated to drive the drum in this direction the pawl is mechanically held out of engaging position. Thus at no time is it possible with my release to drive the rotatable member 10 against the positive lock.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of my speciflca- 15 tion:

Figure 1 is a plan view of an antenna winch embodying my pawl release.

Figure 2 is a side elevation view of the winch of Figure 1, disclosing the releasing means associated therewith.

Figure 3 is a detail view of the pawl releasing mechanism in assembled form.

Figure 4 is a side elevation of the pawl releasing mechanism illustrated in Figure 3. 05

The winch A comprises in general a frame IO M upon which is mounted a motor H A pinion 12 on the motor shaft drives a gear l3 to rotate a "sleeve l4 and a pinion l5 thereupon. Power is transmitted through several speed reducing gears 30 l6, l1, l8, and i9 and 20. The last named gear 20 is bolted to the drum 22 upon which the cable is wound, and the gear 20 and the drum 22 both are mounted upon a shaft 23 which is journalled in suitable bearings 24 upon the frame 10. 35

A controller 25 is provided for controlling the operation of the motor II. This controller is of any type well known in the art, and may be actuated by means of an operating handle 26.

When the handle 26 is moved in one direction, the 0 motor rotates the drum 22 in one direction; and movement of the handle 26 in the other direction acts to rotate the drum 22 in the opposite direction. The controller 25 is mounted in a water and weather proof casing, and allwires or op- 45 crating parts extending through the casing are provided with packed joints to prevent moisture from entering the casing of the controller.

On the side of the drum 22 opposite the gear 20 is secured a ratchet gear 21. This gear is 50 adapted to be engaged by a pawl 28, which is pivotally secured in a bracket 29 on the crossmember 30 of the frame l0. When the pawl 28 is in engagement with the gear 21, the drum 22 is positively locked from rotation in one direction.

A weight arm 32 extends outwardly from the pawl 28 to support an adjustable weight 33. The weight 33 tends to rotate the pawl 28 away from the ratchet gear 21, thereby holding the pawl out of engaging position when it has been moved away from the gear 21.

A shaft 34 is rotatably mounted transversely journalled in the frame It and extends into the housing of the controller 25. A crank arm 35 on the shaft 34 is connected pivotally by a pin 36 to an adjustable link 31, which in turn is connected pivotally by the pin 38 to an ear 39 on the pawl 28.

may be rocked to reciprocate the link31 and the pawl 28, which may thus be moved into and out of operative position engaging the gear 21.

Within the housing of the controller 25, the shaft 34 is provided with an arm 42 "rotatable .therewith. This arm 42 is pivotally connected to alink 43 which in turn is pivotally secured to ,arocker arm 44. The rocker arm 44 is pivotally supported intermediate its ends to a bracket 45 mounted on the top of the controller 25. Upon the operating shaft 45 of the operating handle 26 I provide a cam 41. A shoulder 48 on the cam 41 engages the end 49 of the rocker ,arm 44 when the pawl is in engagement with the ratchet. gear, thus preventing the operating shaft 46 and handle 26 from being rotated in one direction. As long as the pawl 28 engages the gear '21, the shoulder 48 abuts the end 49 of the rocker arm 44, and the controller 25 can not be operated to start the motor H in a direction against the pawl 28.

,Asthe pawl 28 is moved out of engaging position by means of the lever 40, the shaft 34 is rotated by the lever 49 in a counter-clockwise direction, the crank arm 35 pulling the pawl 28 through the link 31 to disengage the pawl.

sirnultaneously, the link 43 is moved downwardly, pulling down the attached end of the rocker arm 44, and moving the end 49 upwardly out of theplane of the cam 41. It will be noted that the lower surface of the rocker arm 44 is :tapered so that when the end 49 is pivoted clear of the shoulder 48 of the cam 41, the shoulder 48 .and the body of the cam are free to move beneath :the rocker arm. When the controller 25 is driving the motor I l in a direction to lower the load, .or against the pawl 28, the rocker arm 44 is pivoted with the end 49 thereof above the cam LL41. Thepawl can therefore not accidentally be moved into engaging position while power is applied to lower the load as the cam 41 holds the end 4530f therocker arm 44 in a raised posi- -tion all during the time the power is turned on.

I"-have. provided a simple mechanical ,means :foraccomplishing a decidedly important purpose. -preciable wear, -nism provided which is apt to fail. My release provides a positive means of preventing the "motor from operating when the pawl is in 'operating position; and a positive means of preventing the engagement of the pawl during operatidnof the motor in one direction. :I have described the releasing means in com- No parts of the release are subject-to apnor is there any delicate mecha- While j bination with a particular type of winch, I desire tohave' it understood that this means is applica- Zble to any pawl or dog engageable with a ratchet gear on a rotatable member used in combination with a ,means .of driving the rotatable member in the direction of rotation against which the A handle lever 49 is connected to the shaft 34' by means of which the shaft 34 prevent motion thereof.

rotatable member is locked when the pawl is in engaging position. 7

In accordance with the patent statutes, I have described the principles of operation of my pawl releasing means, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that this is only illustra tive of a. means of carrying out my invention, and that obvious changes can be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1'. In combination with a controller for a driving means, a rotatable member driven by said driving means, a ratchet gear rotatable with said rotatable member, a pawl engageable with said ratchet gear to prevent rotation of said rotatable member in one direction, means for actuating said pawl into engaging or non-engaging positions, and means actuated by said pawl actuatingineansfor engaging said controller to prevent actuation thereof in one extreme position of said pawl.

2. In combination with a rotatable member, a motor for rotating said member, a manually op erable controller for starting said motor, means e ging said rotatable member for locking the same against rotation in one direction, individually operated means for moving said locking means into and out of operative position, and means operated by said moving means engageable with said controller to prevent actuation thereof to start said motor.

3. In combination with a rotatable member, a motor for rotating said member, a controller for starting said motor to selectively rotate said motor in either direction, means for engaging said rotatable member to prevent rotation thereof in onedirection, means for moving said engag- V 7, ing means into and out of operative position, and

engaging gear, means for rotating said rotatable member, means for controlling said means for rotating said rotatable member to start said rotatable member in a direction of movement preventable by said pawl.

r 5. "A pawl release in combination with a rotatable member having a pawl engaging means thereupon comprising a pawl engageable with said pawl engaging meansto prevent rotation of said rotatable member in one direction, a motor for operating said rotatable member in said one direction, manually movable means for starting and'stopping said motor, and means connected to said pawl and engageable with said manually movable means in one position of said pawl to 6. A release in combination with a rotatable member including means for holding said rotatable member from rotation in one direction, means for moving said holding means into and means for rotating said rotatable member, and

'out of operative position, means for rotating said rotatable member in said one direction, manually movable means for starting and stopping said means connected to said holding means engage- Q able with said manually movable means when said '75 holding means is in operative position to prevent starting of said rotating means in said one direction.

7 A pawl release in combination with a rotatable member including a pawl engageable with said rotatable member to prevent rotation thereof in one direction, a motor for operating said rotatable member in said one direction, a movable controller for starting and stopping said motor, a cam operated by said movable controller, and means connected to said pawl movable into engaging position with said cam when said pawl is moved into engaging position to prevent movement of said controller to start said motor.

8. In combination, a rotatable member, means preventing rotation of said member in one direction, means for moving said rotation preventing means into and out of engaging position, means for rotating said rotatable member in said one direction, means for starting and stopping said means for rotating said rotatable member, means connected with and operating in unison with said moving means engageable with said starting and stopping means in one extreme position of said moving means, to prevent operation of said starting and stopping means, and means on said starting and stopping means engageable with said means connected with said moving means to prevent actuation of said moving means while said starting and stopping means is in position to actuate said rotating means to rotate said rotatable member.

9. In combination, a rotatable member, means for holding said rotatable member from rotation in one direction, means for moving said holding means into and out of operative position, motor means for rotating said rotatable member, a movable controller for starting and stopping said motor, means on said movable controller engageable with said moving means in one position of said moving means, and means on said controller engageable with said moving means to prevent actuationof said holding means when said controller is actuated to start said motor.

10. In combination, a drum, a ratchet gear secured for rotation with said drum, a pawl engageable with said ratchet gear, means for moving said pawl into and out of engagement with said ratchet gear, a reversible motor connected to said drum to rotate the same in either direction, a movable control means for controlling the direction of rotation of said motor, means on said movable control engageable with said pawl moving means when said pawl is in engagement, said means on said movable control engageable with said pawl moving means when said pawl is out of engagement to hold the same out of engagement when said control is moved into position to cause rotation of said motor in one direction.

OLA L. BERBY.