US2654632A - Pivoted jaws forceps tool with locking means - Google Patents

Description

L. C. HERBERT 'PIVOTED JAWS FORCEPS TOOL WITH LOCKING MEANS 2 Sheets-Sheet 1 Filed Nov. 2, 1949 INVENTOR. v lows C. HERBERT v ATTORNEYS Oct. 6, 1953 1.. c. HERBERT PIV OTED JAWS FORCEPS TOOL WITH LOCKING MEANS Filed Nov. 2, 1949 2 Sheets-Sheet 2 JNVENTOR. [cu s C? HERBERT A TTORNE Y5 Patentecl Oct. 6, 1953 PIVOTED JAWS FORCEP-S' TOOL WITH LOCKING Louis '0. Herbert, Burley, Wash.

Application November 2, 1949, Serial No. 124,980

3 Claims. (01. 294-116) This invention relates to the art of forceps tools, and has for its general object the provision of a forceps tool having special jaw support and actuating mechanism which enables operating the jaws from a remote control location at the extreme end of an elongated forceps body or jaw support, the entire instrument being extremely compact and slim to enable reaching with the jaws into remote locations of restricted accessibility.

A related object is to provide such a tool further desirable in that the jaw support and elongated tool body are of such comparatively small cross-section as to enable following the narrow jaws with or without an object grasped between them through even very restricted openings to the hilt or extreme control end of the tool. At the same time such control end remains accessible for convenient control operation of the aws. resides in the characteristic of the jaw-operating mechanism, whereby the amount of operating space required by its handle element is only slight and varies inappreciably during opening and closing of the jaws thereby. This would not be true of'lever-operated forceps in which the lever handles require appreciable space for relative swinging in order to open and close the jaws.

Still another object is to provide in such a tool jaw-operating mechanism having a single control element which can either be operated by direct linear movement thereof to swing the jaws quickly and temporarily, or by rotational movement thereof to close the jaws positively with a greater force, which force is retained thereby until the control element is reversely actuated in positive manner.

Further objects include achieving a forceps of a durable and rugged construction lending itself to convenient and inexpensive manufacture.

Among the various uses of forceps constructed in accordance with the invention is that involved in the manufacture and repair of' radio and other electronic devices requiring placement, removal and relocation of small parts in otherwise inaccessible and remote locations. Still another example of its use is as a convenient tool for reaching into the gullet of a fish to grasp and remove a hook lodged therein. It has numerous additional uses also, such as in automotive work, many of which will become readily obvious from an understanding of the nature of the tool as herein described. The forceps may be made in various sizes, or in sets of several In this connection a further advantage similar tools of different size, to suit a wide range of uses. 7

Described briefly, features of the invention reside in the elongated slender tubular casing or body, carrying at one end pivoted forceps jaws, and at its opposite end a control or handle element which operates jaw-actuating mechanism including a plunger rod extending from one end to the other of the tubular body interior. Wedging cam action between the pivoted jaws and'the tapered end of the plunger rod effects relative closing movement of the jaws by advancement of the plunger rod, whereas opening movement of such jaws preferably is efifected by spring means when the rod is released for retraction or is retracted. Preferably such jaws are pivotally mounted between fiat end extensions of the casing formed by notching the end of the extensions of the casing formed by notching the end of the casing at opposite sides, and the spring means comprises a pair of leaf springs carried by the same end of the casing and extending over the respective notch openings defined between the edges of such end extensions.

A further feature resides in the provision of screw threads on the plunger rod cooperatively to engage a nut element guided for limited axial movement, but restrained against rotation relative to the casing, whereby the plunger rod may be advanced to operate the jaws by direct thrust applied to the plunger rod, or alternatively by rotating it.

Other features, objects and advantages of the invention, including certain details of construction of its preferred form will now be described in greater detail by reference to the accompanying drawings.

Figure 1 is a longitudinal, sectional view of the forceps tool in its preferred form.

Figure 2 is an exploded view of the jaw end of the tool.

Figure 3 is a side view of the jaw end portion and Figure 4 is acorresponding bottom view of such a tool having jaws of modified form; thereof.

Figure 5 isv a side view with parts broken away showing the initial position of the jaw-actuating mechanism when the jaws are opened and the mechanism ready to close them.

Figure 6' is a corresponding view of the tool with its jaws closed temporarily by direct linear thrust applied to the plunger rod.

Figure '7 is a corresponding view of the tool with its jaws closed positively by screw operation of the plunger rod.-

Figure 8 is a longitudinal sectional view of a fragmentary end portion of a tool, illustrating a modification pertaining to the jaw-actuating mechanism.

As shown in Figures 1 and 2, my improved forceps tool comprises the elongated slender tubular casing or tool body l terminating at one end in the flat extensions I2, between which the jaws l4 are received and from which they are pivotally supported. These extensions are conveniently formed, first by notching the end of the casing at opposite sides, and then flattening the resulting extension segments. Each J'aw swings independently about a pivot pin l6 passed through aligned apertures in the jaw and body extensions l2. The respective apertures 18 in the individual extensions are spaced apart by a distance which locates the base ends of the jaws as near together as possible within the dictates of clearance requirements. therebetween, in order to minimize the overall breadth of the jaw head. The jaws shown in Figures 1 and 2 are generally straight. In Figures 3 and 4-. jaws of modified form are illustrated, and these or other special types may be preferred for certain applications.

The base end of each jaw projects appreciably beyond the jaws pivot axis endwise of the tool toward the casing and its outside edge is engaged by a leaf spring 20. The free ends of these springs are bent toward each other to exert localized pressure against the jaws at locations between the tool body and their pivots in all moving positions of the jaws to urge the jaws normally toward open position. The two leaf springs 28 are carried by the jaw-end of the casing It, retained against flattened areas 22 thereon by the clamp collar 24. The collar and springs are permanently secured to the end of the casing. These leaf springs also act as closure members substantially to cover the open notch spaces 26 defined between the side edges of the jaw mounting extensions l2, as shown, preventing entrance of dirt to the space accommodating the pivoted jaw ends.

Within the general rectangular closure defined protectively by the opposite casing extensions l2 and the leaf springs 20, the inner edges of the inwardly projecting base ends of the jaws I l are scarfed, preferably rounded, to form divergent surfaces which constitute cam surfaces 28 mutually engageable by the conical tip of the plunger rod 38, reciprocable lengthwise in the tubular casing Ill. As this conical tip advances into engagement with the cam edges of the base ends of the jaws M, they are wedged progressively apart, and the jaws swung closed correspondingly about pivot pins I6. The cam curvature is preferably such that clamping pressure of the jaws produced by a given thrust of the plunger rod 38 is practically the same when closed upon a large object as upon a smaller object received between them. Moreover, the progressive divergence of the cam edges is so related to the cone angle of the tip of the plunger rod that contact of the cone surface with the cam edges occurs generally midway between between the base and apex of the cone in all operating positions of the jaws. It will be evident that variations in the cam edge curvature in forceps jaws of different design will result in difierent relationships between jaw pressure and plunger rod thrust, but preferably the cam surfaces are shaped so that, for a given increment of linear travel of the operating rod 30, the jaws handle element in the form of an actuating knob 32 fixedlymounted on the end of such plunger rod. The end of the casing adjacent to knob 32 fixedly mounts a hollow enlargement or head 34 having finger-grip extensions 36 projecting laterally from its opposite sides. In the recess of this head is received a nut 38, the threads of which engage complemental threads formed on the plunger rod 3Q over a portion of its length extending an appreciable distance on either side of the nut location generally. A washer 4d closes the open end or" the grip head recess and functions as a stop, limiting movement of the nut 38 in the direction away from the forceps jaws. Opposite movement of the nut is limited by the end of the casing 36 and adjoining annular base wall of the grip headrecess flush with it. The plunger rod may be turned freely in the casing ii) and nut 38, and the nut is free to reciprocate lengthwise of the casing between the described limits. However, the nut fixedly carries a key shown as pin 42 projecting from one side into a longitudinal keyway M in the adjacent recess wall, to prevent rotation of the nut in either direction relative to the casing as the rod is rotated relative to it.

As a result of the foregoing construction characterizing the preferred form of jaw actuating mechanism employed in my improved forceps tool it is possible to close the jaws quickly in opposition to the pressure of springs 28 simply by direct longitudinal thrust applied to the plunger rod 39 without rotating it, moving the rod and jaws from their positions of Figure 5 to those of Figure 6. Alternatively the jaws may be closed positively under comparatively great pressure, although more slowly, by rotating the plunger rod relative to the casing, and hence threading it through the nut 33. As a result the nut will remain in contact with washer [3E and thescrew will react from it to press the conical tip of rod 30 against the cam surfaces of-the jaws. Moreover, this screw-effected pressure of the jaws is retained on any object clamped in them until the plunger rod is retracted by counter-rotation relative to the casing H and nut 38.

As another aspect of tool operation, if, for instance, the jaws have been closed on a particular object by direct or non-rotational actuation of the plunger rod, it is possible, while such object continues to be held between the jaws through a continuation of the direct thrust force applied to the knob 32, to rotate such knob until the nut 38 has progressed into firm engagement with the stop washer M, at which time the thrust force applied to the knob 32 may be removed and the jaws will still firmly clamp the particular object; now by virtue of the nuts pressure reacting from thestop washer 38, on the plunger rod. Alternatively, if the jaws have already been closed on an object by screw action of the plunger rod, and it is desired to release them in a single rapid movement to be executed more quickl than vcan be accomplished by the comparatively slow progressive counter-rotation of the plunger rod, the rod may first be counterrotated at the same time a direct thrust force is steadily applied manually to the knob 32, to hold the jaws closed, as the nut 38 moves away from the stop washer. After the nut 38 has progressed a sufficient distance away from the stop washer the jaws may be opened deftly in a single quick movement by sudden release or retraction of the knob 32, to permit the springs 2t to swing the jaws open as the conical tip is retracted. i

The foregoing modes of operation may be readily appreciated by reference to'Figures 5, 6 and 7. In Figure 5 the nut 38 is located in starting position on the threaded portion of the plunger rod, and in relation to the stop washer 40, so that closure of the jaws may be accomplished by advancing the plunger rod by direct longitudinal force applied to the knob 32, into the position of Figure 6, as explained, for instance, by pressure of the thumb with the first and second fingers of the same hand hooked around the respective finger grips 36. If, instead of using a single hand for this operation, the fingers of one hand press against the grips 36 and the fingers of the other hand are used to press knob 32, the latter fingers may further be manipulated after the initial gripping operation to rotate the knob and rod for moving the nut 38 from the position of Figure 6 into that of Figure 7 thus positively retaining the jaws in gripping position.

Conversely, if the jaws have been closed by rotation of the knob 32 until, by reaction from nut 38 engaging the stop washer 40, the rods conical tip is pressed positively against the cam edges of the jaws, they may be opened quickly in the following manner. Holding the grips 36 with one hand the knob can be rotated by the fingers of the other hand, while axial inward pressure is maintained on the knob, until the nut 38 has been shifted from the position of Figure 7 to that of Figure 6. Then, if the axial pressure is released quickly, the springs 20 will open the jaws immediately and reciprocate the rod 30 and nut 36 back to the position of Figure 5.

In gripping objects positively by rotation of knob 32, the attainable jaw pressure may be great because of the combined effects of screw action of the rod and nut and wedging action of the rods tip against cam surfaces. The large size of knob 32 provided for rotating the plunger rod is of direct aid in the same regard. Preferably the periphery of this knob is knurled, so that it may be turned more readily against resistance of the jaws holding a particular object.

Figure 8 illustrates a modification of the rod shifting mechanism wherein the casing, designated if! in this view, is itself threaded at its handle or jaw-actuating control end for direct engagement with a threaded portion of the plunger rod 30'. In this case opening and closing of the jaws of the forceps tool is always positive, depending solely upon screw action of the rod in the casing. The effect is the same as if the nut 38 in the other form of tool were fixed in the cavity of the casing instead of being shiftable axially in it.

In the use of my improved forceps tool, if, for instance, it is desired to retrieve a small radio part, such as a resistor, which has been accidentally dropped through a maze of wires and other assembled elements into an otherwise inaccessible and remote location inside the radio chassis,

ordinarily the jaws 14 would first'be closed to avoid catching on intervening objects during insertion of the tool until it is advanced to the location of the misplaced'resistor- In efiectby remote control the jaws are then opened and the resistor clamped between them for withdrawal with the tool. In this retrieving operation control of the jaws is accomplished entirely by manipulations at the extreme opposite or outer end of the forceps tool. In fact, the entire length of the tool, except for the head 34 and knob 32, can be inserted through an opening into a confined space to perform a desired operation without inconvenience in the control of knob 32 operating the jaw actuating mechanism according to any of the described modes of operation.

A further special use of the tool is in retrieving fishhooks from the gullet of fish. In this and other cases I may prefer jaws of the curved form, shown in Figures 3 and 4. In fact, the shape of the jaws may be adapted to the particular application without departing from the invention herein described.

I claim as my invention:

1. A forceps tool comprising a tubular casing, cooperating jaws pivotally mounted on one end of said casing, a rod separate from said jaws extending through said casing and having an externally threaded portion remote from said jaws, jaw-actuating means separate from and engageable with said jaws and operable by said rod moving lengthwise toward said jaws to swin them toward closed position, spring means operable to urge said jaws toward open position and said rod lengthwise away from said jaws, a nut threadedly received on the threaded portion of said rod, means interconnecting said nut and said casing and operable to guide said nut for limited movement axially of said casing and to restrain appreciable rotative movement thereof relative to said casing, stop means carried by said casing, engageable by said nut and limiting axial movement thereof away from said jaws, and handle means on the end of said rod remote from said jaws and operable to reciprocate said rod non-rotatively and said nut conjointly lengthwise toward said jaws for effecting relatively rapid tweezer jaw closing lengthwise movement of said rod and turnable to rotate said rod relative to said nut and jaws for effecting positive locking of the jaws in clamped position.

2. A forceps tool comprising a tubular casing, coperating jaws pivotally mounted on one end of said casing, a rod separate from said jaws extending through said casing and having an externally threaded portion adjacent to the end of said casing remote from said jaws, jaw-actuating means separate from and engageable with said jaws and operable by said rod moving lengthwise toward said jaws to swing them toward closed position, spring means operable to urge said jaws toward open position and said rod lengthwise away from said jaws, a nut threadedly received on the threaded portion of said rod, a recessed head larger than said casing in cross section, carried by the end of said casing remote from said jaws and having a socket therein receiving said nut, guiding the same for axial movement relative to said casing and restraining appreciable rotation of said nut relative to said casing, stop means carried by said head, engageable by said nut and limiting axial movement thereof away from said jaws, and handle means on the end of said rod remote from said jaws and operable to reciprocate said rod alteferences Cited in the :file of this patent UNITED STATES PATENTS Number Number "Name Date Howell Jan. 19,1869 'Huthinson Nov. 14, 19.05 Torvick July 10, I917 "Hirsch Mar. '3, 1936 Hanchock 7.. Sept. 2, 1941 LFOREIGN "PATENTS Country Date Norway June 6, 1921 Norway 'Sept.21, 1942

Images