US2058855A - Ratchet screw driver - Google Patents

Description

Oct. 27, 1936. J. w. CHAPMAN 2,058,855

RATGHET S CREW DRIVER Filed Oct. 9, 1955 INVENTOR John W Chapman.

ATTORNE Patented 9ct. 27, 1936 PATENT OFFICE m'rcnnr scnnw 1mm John w. cam xeminmh. Conn. Application October-9, 1935. Serial No. 44,244

This invention relates to screw drivers, and more particularly to a ratchet screw driver which will be readily reversible.

One object of this invention is to provide a. ratchet screw driver in which the ratchet mechanism is encased within the interior of the handle and the ratchet head is provided on its opposite sides with a pair of opposed selectively used screw "driver blades of different sizes.

A further object is to provide a ratchet screw driver of the above nature in which the handle is made of two complementaryhalves having abutting marginal flanges and alined flanged holes adapted .to serve as bearings for a double-ended A further object is to provide a ratchet screw I driver of the above nature in which the ratchet control pawl is laminated, and is adapted to journal about a hardened steel washer.

A further object is to provide a ratchet screw driver of the above nature which will be simple in construction, inexpensive to manufacture, easy to assemble and manipulate, compact, and very efficient and durable in use.

With these and other objects in view, there have been illustrated on the accompanying drawing two forms in which the invention may be conveniently embodied in practice.

In the drawing:

Fig, 1 represents a. perspective view of the ratchet screw driver embodying the invention.

Fig. 2 is a plan view of the screw driver with the upper half section of the handle removed to show the interior construction.

Fig. 3 is a transverse sectional view of the ratchet head end of the handle, the section taken along the line 3-3 of Fig. 2.

Fig. 4 is an exploded perspective view of the screw driver'showing the detailed construction of the several parts prior to assembly.

Fig. 5 is a perspective view of a modified form of ratchet head having the standard type of screw driver blade attached thereto.

Fig. 6 is a longitudinal sectional view of the laminated pawl member.

Referring now to the drawing in which like reference numerals denote corresponding parts throughout the several views, the numeral ill indicates generally thehandle of the ratchet screw tions II and I2, respectively. Each section II,

i2, is formed 'with upstanding marginal flanges I3 and I4, extending around its entire periphery.

The handle i is preferably made tapered, and

' has a rotatable ratchet head If: fitted in the large end thereof.

The ratchet section of the head i is embraced by the curved end flange at the large end of the handle, and said head has a pair of oppositely extending cylindrical shanks l3 and I1 joumaled within a pair of outstanding alined annular flanges l8, IS on the handle sections ii, The outer flat surfaces of the cylindrical shanksv I6 and I! are formed with a pair of opposed upstanding screw driver blades 2l and 22 preferably made of two sizes to accommodate different sizes of screws, and also preferably arranged at right-angles to each other. In order to selectively lock the ratchet wheel l5 according to the direction of operation desired, provision is made of an elongated reversible pawl member 24v provided with a pair of detent teeth 25, 25 located on the opposite sides of the forward end thereof for engaging between the teeth of the ratchet wheel 20. The pawl member 24 is held in its two operating positions by means of a flexible elongated flat leaf-spring 26, one end of which engages in a notch 21 formed in the rear end of the pawl member 24, the oppositeend of said spring being seated within a notch 28 formed in an anchor block 29 located in the smaller end of the handle Ill.

The pawl member 24 is adapted to be manually thrown from one of its extreme positions to the other by means of a reversing lug 30 formed on the upper section of said pawl 24, which lug 30 projects upwardly through an arcuate slot 3| provided in the upper half section II, so as to be readily accessible for manual operation.

The pawl member 24, as best shown in Fig-2, is formed with two pairs of diametrically opposed substantially parallel flattened edges 32, 33 and 34, 35 which, when *1 use, are adapted to abut solidly against the marginal flanges l3 and [4 of the stampings II and i2. .This construction serves to reinforce the ratchet wheel l5 when the screw driver is being operated.

As shown in Fig. 4, the pawl 24 is preferably laminated, being built up from three superposed metal blanks 36, 31 and 38, each of said blanks having alined apertures 39 adapted to be journaled about a hardened steel washer 40 rotatably mounted upon a rivet 4|, the latter also serving to hold the handle sections II and I2 together. In order to prevent relative twisting of the laminated blanks 36, 31 and 28 of the pawl 24 with respect to each other, the two lower blanks 31 and 38 are provided with cooperating alined drifted interfitting raised cups 42. The cup 42 on the intermediate blank 31 is adapted to engage in an aperture 43 in the upper blank 36. The reversing lug 30 previously referred to is preferably struck up from the body of the upper blank 36.

As clearly shown in Fig. 6, the cylindrical upper projections of the cups 42 on the two lower blanks 31 and 38 are made slightly less in diameter than the bottom sockets 42a of said cups. This construction causes the sections of the pawl 24 to snugly interflt with each other and be held in substantially rigid lateral relationship. It will be noted that the blanks 31 and 38 are identical. and hence, interchangeable in use. They also may obviously be made from the same set of tools.

The anchor block 29 at the rear of the handle Ill is likewise laminated, consisting f three superposed metal blanks 44, 45 and 4%, provided with alined apertures 41, through which projects the shank of a rivet 48 which serves not only to hold said anchor block in position, but also to attach the rear ends of the handle half sections permanently together. If desired the middle blank 45 of the anchor block may be integrally formed with a screw driver blade extension 49 which is adapted to project through cut-out sections 50 and Si in the smaller rounding portions of the upstanding flanges l3 and I4. While the pawl 24 and anchor block 29 are shown as made out of laminated blanks, it is also within the scope of the invention to make said parts out of a single blank. The washer 40 may also be laminated if desired.

Operation In operation, to remove a screw, assuming the pawl 24 and the leaf-spring 26 to be in the positions shown in full lines in Fig. 2, with the lower detent tooth 25 engaged between two adjacent teeth of the ratchet wheel 20, the movement of the handle Ill in a counter-clockwise direction will cause the ratchet driven blade 22 to twist the screw outwardly a short distance. The handle in will then be swung in a clockwise direction without turning the screw, the pawl swinging backwardly suificiently to permit the teeth of the ratchet to pass by the tooth 25.

When it is desired to insert the screw, it will merely be necessary to move the lug 30 manually upwardly to cause the pawl and spring to assume the dotted line positions shown in Fig. 2.

One advantage of the present invention is that the tapered form of the handle I ll permits the easy attachment of a tubular extension member whenever it is desired to increase the mechanical advantage of the ratchet screw driver. a

In Fig. 5 'is shown a modified form of ratche head I511, in which a regulation type of screw driver blade 52 is substituted for the relatively short screw driver blades 2| and 22 as disclosed in the first form of the invention.

While there have been disclosed in this specification two forms in which the invention may be embodied, it is to be understood that these forms are shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosures but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new and for which it is desired to secure Letters Patent, is:

1. In a ratchet tool, a handle comprising two complementary hollow half sections each having upstanding marginal flanged edges adapted to define a chamber within said handle, a tool carrying ratchet wheel journaled in one end of said handle, a spring controlled rockable multisided elongated pawl having a double-pointed end engaging said ratchet wheel, said pawl having two sets of opposed flat sides so arranged that selectively both sides of either set will abut against the respective opposite flanged edges of said handle simultaneously to provide a pair of anchoring faces for reinforcing said pawl, for both the forward and reverse rotation of said ratchet wheel.

2, In a ratchet screw driver, a hollow flat casing having an arcuate slot in one face thereof and having its opposite sides slightly inclined with respect to each other and provided with marginal upstanding flanged edges, a ratchet wheel and a cooperating ratchet locking pawl unit journaled in said casing, said pawl having two sets of opposed straight sides so arranged that selectively both sides of either set will engage said opposite flanged edges and a manual shifting lug on said pawl extending, up through said slot, the opposed sides of said pawl being inclined at the same angle as the opposite sides of said casing.

JOHN W. CHAPMAN.

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