US1372868A

US1372868A - Operating mechanism for lifting-jacks

Info

Publication number: US1372868A
Application number: US365173A
Authority: US
Inventors: Charles D Derby
Original assignee: Joyce Cridland Co
Current assignee: Joyce Cridland Co
Priority date: 1920-03-12
Filing date: 1920-03-12
Publication date: 1921-03-29
Anticipated expiration: 1938-03-29

Description

c. 0. DERBY. OPERATING MECHANISM FOR LIFTING JACKS- APPLICATION FILED MAR. 12, I920- 1,3?fi868 Patented Mam 2Q, 1921..

CHARLES D. DERBY, 01F D.-.YTO1\T, OHIO, ASSIGNOB TO THE JOYCE-CRIDLAND CQM'PANY, 01-5 DAYTON, OHIO, A CORPORATION OF OHIO.

Specification of Letters 2atent.

or ented 29, 15521.

Application filed March 12, 1920. Serial No. 365,173.

To all whom it 722( concern Be it known that l, Crrannns D. DERBY, a cijaen of the United States, residing at too, in the county of Montgomery and Ohio, have invented certain new :ful improvements in Operating hanIsm for Lifting-lacks, of which the owingz is a specification, reference being therein to the accompanying drawing. is invention relates to operating -mecha nism i r lifting jacks and the like, and more particularly to what is known as a fine toothed ratchet mechanism.

@ne object of the invention is to provide a mechanism or" this kind which will be simple in its construction and operation; and in which the pawl will engage the ratchet wheel with a strong gripping action and will have no tendency to slip.

A further object of the invention is to provide a mechanism of this kind which can be easily reversed by the manipulation of the lever and without the necessity of the operator crawling under or reaching under the load.

Other objects of the invention will appear as the mechanism is described in detail.

Figure l is a perspective view of a jack embodying; my invention; Fig. 2 is a transverse sectional view. taken through the ratchet wheel; and Fig. 3 is a side elevation of the ratchet mechanism.

In these drawings I have illustrated one embodiment of my invention and have shown the same as applied to a lifting jack of a well known construction and which is designed in the present case, as a truck I It will be understoood, however, that this embodiment of the invention has been chosen for the purpose of illustration only and that the invention be applied to jacks or various kinds, or to other devices, in which a ratchet mechanism may be employed.

its here illustrated, the jack comprises a base 1 having mounted therein a screw 2 in which is mounted a second screw 3 to the upper end of which is secured the cap, or load engaging member, 4. The telescoping screws 2 and 3 constitute the lifting mem ber of the jack and are threaded in opposite directions so that the rotation of the outer sirew 2 will not only cause this screw to be moved lengthwise of the base 1 but will also cause the inner screw 3 to be moved length- ,M o. a no to wise relatively to the outer screw. Rotatory movement is imparted to the outer screw by means oi. a. suitable actuating member, such as a ratchet wheel 5 which is rigidly secured to the upper end thereof and which in the present instance is provided with radial teeth which are of a ll-shape. Rotatably mounted for movement about the axis of the ratchet wheel is a lever supporting structure which, as here shown, comprises two

plates

6 and 7 arranged respectively above and below the ratchet wheel. are preferably rigidly connected one to the other and in the present instance they are united by a semi-circular flange 8 which is formed integral therewith and extends about approximately one half of the ratchet wheel. The plates and flange thus constitute a housing inc-losing the ratchet wheel but open along one edge to expose the teeth of the ratchet wheel for engagement by the pawl. The

plates

6 and 7 are provided with outwardly extending portions 9 to receive between them the end portion of a lever 10, which preferably comprises a socket portion adapted to receive a bar, or spike, 11. Rigidly secured to the lever and extending; in opposite directions therefrom along the edge of the actuating member are two projections or

pawls

12 and 13 each having' near its outer end a portion adapted to he moved into and out of operative engagement with the actuating member by the manipulation of the lever. When the actuating member is in the form of a ratchet wheel the pawl may be provided with teeth and, in the present instance, each pawl is shown a having a series oi t -shaped teeth adapted to mesh with the teeth of the ratchet v reel. The

pawls

12 and 13 are of such length and are so arranged with relation to the lever that when the lever is moved about its axis the pawl on that side toward which the lever is moved will be moved in a substantially radial direction into engagement with the teeth of the ratchet wheel, thus causing the teeth of the pawl to be seated firmly in the recesses be tween the teeth of the ratchet wheel and to the same with a gripping action, which will eii ectually prevent any slipping or" the pawls relatively to the ratchet wheel. It will be apparent that when the lever is actuated it will first move about the axis of its pivotal connection to the supporting These plates structure to cause the pawl on that side thereof toward which it is moved to engage the teeth of the ratchet wheel and that at ter this engagement has been established, the continued movement of the lever will cause the supporting structure and the ratchet wheel to rotate thus actuating the lifting member. Upon the return movement of the lever it will be first moved about the axis of its pivotal connection to the supporting structure to disengage the pawl from the ratchet wheel and the further movement thereof will'rotate the supporting structure relatively to the ratchet wheel to permit the lever, and the pawl to be returned to their initial positions, Means provided to so limit the pivotal movement of the lever in a return direction that the pawl on the opposite side thereof will. not be moved into engagement with the ratchet wheel but will be held in a neutral position while return movement is imparted to the lever and to the supporting structure. To this end I have mounted on the supporting structure a stop 14 arranged in the path oi a dog 15 mounted upon the lever and so arranged that when the lever has been moved to sul stantially a central position with relation to the supporting structure, the dog will engage the stop and check the pivotal movement of the lever. The dog is preferably yieldable so that it can be moved across the stop to permit the mechanism to be reversed, to move the lifting member in the opposite direction. In order that the lever may assume its central, or neutral, position when the dog'15 is located on either side of the A stop 14 l have pivotally mounted the stop,

as shown at 16, and have provided the same with oppositely extending projections 17 and 18 arranged to engage the opposite sides of a fixed stop 19 on the supporting structure, this fixed stop comprising, in the pres ent instance, the head of a bolt 20 by means of which the lever is pivotally connected with the supporting structure. The projections 17 and 18 on the movable stop 1st are so arranged with relation to the lined stop 19 that the movable stop will have a limited pivotal movement, which is suficient to position the same on either side of a central line, that is, a line extending through the axis of the ratchet wheel and through the axis of the lever. The arrangement, of the movable stop is also such as to permit this stopto move with the lever until the pawl has engaged the ratchet wheel, as shown in Fig. 2. Upon the return movement of the lever, from the position shown in full lines in Fig. 2, the stop will move about its axis 16 until the projection 17 engages the fixed stop 19 and thus checks the pivotal movement of the lever and causes the supporting structure to move therewith. W hen it is desired to reverse the operation of the ack this may be accomplished by applying suflicient force to the lever to cause the pawl 15 to yield and ride over the end of the movable stop 14. This may be quickly and easily acconplished by a jerk on the end of the lever, thus avoiding any necessity for the operator crawling under, or reaching under, the load.

The operation of the mechanism will be readily understood from the foregoing d scription and will be apparent that l have prvided an operating mechanism which is very simple both in its construction ent that the operating mechanism may be very quickly and easily reversed from a point remote from the jack.

l hile l have shown and described one embodiment of my invention 1 Wish it to he understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention what I claim as new and desire to secure by Letters Patent is: l

1. in a lifting jack, a lifting member, a ratchet wheel operatively connected therewith, a lever supporting structure mounted :lor rotation about the axis of said ratchet wheel, a lever pivotally; mounted on said structure, pawls carried by said lever and extending in opposite directions therefrom about said ratchet wheel and so arranged that the movement of said lever about its axis will cause that pawl toward which the lever is moved to engage said ratchet wheel, and means to limit the return movement of said lever about its pivotal connection to said supporting structure, said means being reversible by the manipulation o1 said lever to enable the movement oi said lever to be limited in either direction.

2. In a lifting jack, a lifting member, a

ratchet wheel operatively connected there- 7 with, a lever supporting structure mounted and cooperating stops carried by said lever and said supporting structure to limit the return movement of said lever about its pivotal connection to said supporting structure, one of said stops being yieldable to permit it to pass the other stop and to re verse the operation of the jack.

3. In a lifting jack, a lifting member, a ratchet wheel operatively connected therewith, a lever supporting structure mounted for rotation about the axis of said. ratchet wheel, a lever pivotally mounted on said structure, pawls carried by said lever and extending in opposite directions therefrom about said ratchet wheel and so arranged that the movement of said lever about its axis will cause that pawl toward which the lever is moved to engage said ratchet wheel, a stop mounted on said supporting structure for a limited pivotal movement, and a dog yieldably mounted on said lever and arranged to cooperate with said stop to limit the movement of said lever in one direction about its pivotal connection with said supporting structure.

4. In a lifting jack, a lifting member, a ratchet wheel operatively connected therewith, a lever supporting structure mounted for rotation about the axis of said ratchet wheel, a lever pivotally mounted on said structure, pawls rigidly secured to said lever and extending in opposite directions therefrom about said ratchet wheel and so arranged that the movement of said lever about its axis will cause that pawl toward which the lever is moved to engage said ratchet wheel, a dog yieldably mounted on said lever, a stop pivotally mounted on said support ing structure and having a part arranged to cooperate with said dog to limit the movement of said lever in one direction about its pivotal connection with said supporting structure, said movable stop having oppositely extending projections, and a fixed stop carried by said supporting structure and arranged between the projections of said movable stop to limit the pivotal move ment of the latter.

In a lifting jack, a lifting member, a ratchet wheel operatively connected therewith, a lever supporting structure mounted for rotation about the axis of said ratchet wheel, a lever pivotally mounted on said structure, pawls rigidly secured to said lever and extending in opposite directions there from about said ratchet wheel and so arranged that the movement of said lever about its axis will cause that pawl toward which the lever is moved to engage said ratchet wheel, and cooperating stops carried respectively by said lever and said supporting structure to limit the movement of said lever in one direction about its pivotal connection with said supporting structure, one of said stops being of such a character that the rela- ,scs.

tive positions of the two stops can be reversed by the manipulation of said lever.

6. In a lifting jack, a lifting member, a ratchet wheel operatively connected therewith, a lever supporting structure mounted for rotation about the axis of said ratchet wheel and comprising upper and lower members, a lever having a part extending between the upper and lower members of said supporting structure and pivotally connected therewith, said lever also having pawls formed integral therewith and extending in opposite directions therefrom about said ratchet wheel, a dog yieldably mounted on said lever, and a stop mounted on said structure to cooperate with said dog and having a limited pivotal movement to permit it to be positioned on either side of said dog when said lever is in a neutral position.

7. In a lifting jack, a lifting member, an actuating member operatively connected with said lifting member, a lever supporting structure mounted for rotation about the axis of said actuating member, a lever pivotally mounted on said structure, and pawls rigidly secured to said lever and extending laterally therefrom in different directions, each pawl having a portion arranged to be moved into and out of gripping engagement with said actuating member by the move ment of said lever about its axis, and means to limit the return movement of said lever, said means being reversible by the manipulation of said lever.

8. In a lifting jack, a lifting member, an actuating member operatively connected with said lifting member, a lever supporting structure mounted for rotation about the axis of said actuating member, a lever pivotally mounted on said structure, pawls secured to said lever and extending laterally therefrom in difierent directions, each pawl having a portion arranged to be moved into and out of gripping engagement with said actuating member by the movement of said lever about its axis, and cooperating stops to limit the return movement of said lever about its pivotal connection to said supporting structure, one of said stops being reversible to engage either side of the other stop and said other stop being adjustable relatively to the reversible stop.

9. In a lifting jack, a lifting member, an actuating member operatively connected with said lifting member, a lever supporting structure mounted for rotation about the axis of said actuating member, a lever pivotally mounted on said structure, pawls secured to said lever and extending laterally therefrom in different directions, each pawl having a portion arranged to be moved into and out of gripping engagement with said actuating member by the movement of said lever about its axis, a stop pivotally mounted on said lever supporting structure, means to limit said lifting member, a lever supporting structure mounted for rotation about the axis of said actuating member, a lever pivetally mounted on said structure, pawls secured to said lever and extending laterally therefrom in different directions, each pawl having a portion arranged to be moved into and out of gripping engagement with said actuating member by the movement of said lever about its axis, a stop mounted on said lever supporting structure, a second stop pivotally mounted on said lever supporting structure and having parts arranged on the opposite sides of the first mentioned stop to limit the movement of said pivoted stop, and a yieldable stop carried by said lever and adapted to engage either side of said pivoted stop.

11. In a lifting jack, alifting member, an actuating member operatively connected With said lifting member, "a lever "supporting structure mounted for rotation about the axis of said actuating member, a lever pivotally mounted on said structure, and paWls rigidly secured to said lever and extending laterally therefrom in different directions, each pawl having a portion arranged to be moved into and out of gripping engagement with said actuating member by the movement of said lever about itsaxis, and cooperating stops carried by said lever and said supporting structure, respectively, to limit the return movement of said lever about its pivotal'connection to said supporting structure, one of said stops being yieldable to permit it to pass the other stop and to reverse the operation of the V In testimony whereof, I atlix my slgnature hereto.

CHARLES l). DERBY.