US 977957 A
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Description (OCR text may contain errors)
Patented Dec. 6,1910.
G. 0. LEOPOLD. I RATGHET MECHANISM FOR SCREW DRIVERS APPLICATION FILED MAY 22, 1909.
TinrTnn sTaTns raTnnT orTrc GEORGE O. LEOPOLD, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO NORTH BROS IVIFG 00., 0F PHILADELPHIA, PENNSYLVANIA, A CORPORATIQN OF PENNSYL- VANIA.
RATCHET MECHANISM FQR SCREW-DRIVERS, 860.
Specification of Letters Patent.
Patented Dec. 6, 1910..
Application filed May 22, 1909. Serial No. 497,649.
To all whom it may concern:
Be it known that I, GEORGE O. LEOPOLD, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Ratchet Mechanism for Screw-Drivers, Drills, Etc, of which the following is a specification.
My invention relates to certain improvements in ratchet mechanisms especially applicable to screw drivers, ratchet drills and other small tools, but it is to be understood that it can be used for other purposes without departing from the essential features of the invention.
The object of my invention is to simplify the ratchet mechanism, to reduce the number of parts, and to prevent the accidental displacement of the pawls when in engagement with the ratchet wheel.
In the accompanying drawing :--F igure 1, is a view of a screw driver showing the application of my improved ratchet mechanism; Fig. 2, is an enlarged view of part of Fig. 1, with the casing removed; Fig. 3, is a longitudinal sectional view on the line 33, Fig. 2; Fig. 4, is a transverse sectional view on the line 4t, Fig. 8; Fig. 5, is a transverse sectional view on the line 55, Fig. 3; Figs. 6, 7 and 8, are views showing the different positions of the pawls; Fig. 9, is a perspective view of the ratchet wheel; F ig. 10, is a perspective view of the pawl; and Fig. 11, is a perspective view of the pawl spring. 7
A is the handle of a screw driver in the present instance. This handle has a portion D upon which is mounted the barrel D forming a support for the spindle B and the ratchet mechanism.
In the present instance the ratchet mechanism can be shifted into three different positions, in the first position the handle will drive the spindle to the right and ratchet to'the left; in the second position the parts will be locked so that the spindle will turn with the handle as in an ordinary screw driver; and in the third position the handle will turn the spindle to the left and ratchet to the right, as illustrated in Figs. 6, 7 and 8.
The spindle B of the screw driver extends into the barrel D which is secured to the handle A in any suitable manner, and the end Z) of the spindle is adapted to a bearing plate 0 within the barrel at the end of the handle.
B is the ratchet wheel having teeth cut as shown in Figs. 3, i and 5, and these teeth are beveled at each end 6 as illustrated, so as to clear the pawls and also to allow the pawls to more readily enter the space between the teeth when they are shifted.
c is a locking plate which projects through a slot in the barrel D and in front of the ratchet wheel B, as indicated in Fig. 4.
The barrel D is recessed for the reception of the sliding pawl E which is made as shown in Fig. 10 in the present instance, and in order to form slideways for the pawl I notch the barrel at (Z on each side of the recess for the reception of the extensions 0 and e 011 the pawl. These extensions are connected together by a longitudinal member c having a pin 6 in the present instance, which extends through the slot (Z in the casing D inclosing the barrel D. Projecting inwardly from one of the extensions 0 is a pawl z and projecting inward from one of the extensions c is a pawl both these pawls are made integral with the slide E; the central portion 6 of the slide being raised sufiiciently to clear the ratchet Wheel B.
In order to yieldingly hold the ratchet slide on its ways, I provide a spring G having ends 9, g which rest upon each end of the ratchet slide and have turned down portions g 011 each side of the ends, as shown in Fig. 11. These turned down portions rest on each side of the central member 6 of the pawl e and also rest against the end members 6, 6 so that the spring must move with the pawl. The spring is crimped at the center 6 on each side of the hole through which the pin 6 passes; the hole in the spring being of such diameter as to receive the head of the screw pin, as illustrated in Figs. 3 and 5. The crimped portions g are adapted to the notches (Z in the walls of the slot d Fig. 1, so that the pawl when shifted from one position to another is held in positionby the crimped portion 9 extending into the slots; the crimped portions being beveled at each side, as indicated in Fig. 10, allow the pawl to be shifted when pressure is applied.
The operation of the ratchet mechanism is as follows :The sliding pawl, when shifted to the position illustrated in Fig. 6, is in position to turn the spindle toward the right; the pawl 2' being in engagement with the ratchet wheel and the pawl a" being free shown in Fig. 8, then the pawl z" is in engagement and the pawl i is free and the spindle can be turned to the left by turning the handle, but when the handle is turned to the right the pawl will ratchet so that the handle will turn without turning the spindle.
It will be noticed that the ends of the pawls i, i are beveled (Fig. 10), and by beveling the ratchet wheel, as shown, the pawls will, when moved forward, ride upon the ratchet wheel and into engagement. Furthermore, the beveling of the pawl enables it to more readily enter the spaces be tween the teeth of the wheel,
1. The combination in ratchet mechanism, of a support, a spindle mounted in the support, a ratchet wheel on the spindle, a sliding pawl piece having two pawls adapted to slide on the support, one of said pawls extending toward the center from one end of the pawl piece and the other extending toward the center from the other end of the pawl piece, said pawl pieces lying parallel to the axis of the ratchetwheel, the pawls terminating short of the center so that they will not overlap, the width of the ratchet being less than the length of the pawl so that either one or the other or both of the pawls will engage the ratchet wheel.
2. The combination in ratchet mechanism, of a support, a spindle mounted in said support, a ratchet wheel on the spindle, a sliding pawl piece having end members and a connecting central member, the pawl extending from one end member toward the center at one side of the central member, a second pawl ext-ending from the other end member toward the center on the other side of the central connecting member, said pawls lying parallel to the axis of the ratchet wheel, the ends of the pawl stopping short of the center of the oawl piece so as not to overlap, the said ratdhet wheel being less in width than the length of the pawls so that the pawl piece can be shifted to throw into engagement either one or the other or bot-h of the pawls with the ratchet wheel.
The combination of a barrel, a spindle mounted in the barrel and having a ratchet wheel thereon, the teeth of the ratchet wheel being beveled at each end, the barrel having slideways, parallel to the axis of the ratchet, a sliding pawl piece having end members adapted to the slideways and a central connecting piece with pawls projecting toward the center from each end piece, said pawls having beveled ends, and means for holding the pawl piece onto its slideways.
4. The combination of a barrel, a spindle adapted to bearings in the barrel, a ratchet wheel on the spindle, a sliding pawl piece having pawl's arranged to engage the ratchet wheel and having a central member, a spring mounted above the pawl piece and having project-ions resting on the end of the pawl piece and turned down portions extending on each side of the central member ofthe pawl piece so as to keep the spring central,
and a casing inclosing the above described parts. 5. The combination of a. barrel, a spindle mounted in the barrel, a ratchet wheel on the spindle, slidew-a'ys on the barrel, a pawl piece having a "central member and end members, said end members resting upon the 'slideways, a pawl projecting from each end piece toward the center, a spring resting upon the pawl piece and held so as to move with it, a casing, a slot in the casing having a series of notches in its walls, a pin projecting from the pawl piece through the slot in the casing, the spring having a central opening for the free passage of thepin 9 5 7. A spring for ratchet mechanism 'co n- U sisting of a body portion having ends shaped to bear upon a pawl piece and having downwardly projecting portions at each end to hold the spring laterally to the pawl piece and having a central opening throi'igh which an operating pin may pass, and V=shaped projections on each side of the central opening to engage notches in the inclosing casing of the ratchet mechanism to which the spring is applied. o
8. The combination in a ratchet screw driver, of a handle, a hollow barrel mounted on the end of the handle, a spindle, a ratchet wheel on the spindle, said ratchet wheel being mounted within the barrel, a bearing plate in the barrel receiving the inner end of the spindle, a locking plate bearing against one end of the ratchet wheel and acting with the bearing plate to hold the spindle position, said barrel having slideways, a one piece double pawl having extensions resting on the slideways, said pawl through an opening in the spring and having members shaped to engage the teeth through the slot in the casing, and by which of the ratchet wheel, a casing secured to the I the pawl is shifted. barrel and inclosing the mechanism, said I In testimony whereof, I have signed my 5 casing having a slot therein and notched on name to this specification, in the presence of 15 each side of the slot, a spring shaped at each two subscribing Witnesses. 7 end to engage the pawl so that it will slide GEORGE O. LEOPOLD. with the pawl and having a projection Witnesses: adapted to enter the notches in the casing, 21 WVM. E. SHUPE,
10 pin projecting from the pawl and passing WM. A. BARR.