US2988941A

US2988941A - Pliers

Info

Publication number: US2988941A
Application number: US852322A
Authority: US
Inventors: Charles H Ortman
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-11-12
Filing date: 1959-11-12
Publication date: 1961-06-20
Anticipated expiration: 1978-06-20

Description

June 20, 1961 c. H. ORTMAN PLIERS 2 Sheets-Sheet 1 Filed NOV. 12, 1959 IN V EN TOR.

1 CHARLES/l 012mm BY A rroRNEY June 20, 1961 c. H. ORTMAN PLIERS 2 Sheets-Sheet 2 Filed NOV. 12, 1959 CHARLES H. ORT'MA Arr-we've) United States atentfOfiice 2,988,941 PatentedJune 20, 1961 Filed Nov. 12, 1959, Ser. No. 852,322 I 3 Claims. (Cl. 81-344) This invention relates to pliers and particularly to pliers of the pivoted jaw type having meansjassociated therewith for quickly exerting a powerful grip upon apiece to be gripped between the jaws.

It is one of the objects of this invention to construct a tool such as pliers of the above mentioned type which is capable of gripping an object between the jaws of the tool by the manual application of a relatively light closing force to the handles of the tool which force is thus multiplied many fold into a positive, powerful gripping force to the jaws for securely gripping a piece therebetween.

Another object of the invention consists in pliers comprising a fixed jaw and a movable jaw pivotally connected to the fixed jaw and the provision of means intermediate the movable jaw and an extension of the fixed jaw to apply a powerful gripping force to the jaws.

A further object of the invention is the provision of I compound leverage means for operating the movable jaw with relation to the fixed jaw.

Another object is the provision of a handle operated mechanism for selectively and quickly setting the jaws of the pliers to receive a workpiece of'selected size and to subsequently, by the manual application of a relatively light closing force on the handles, positively gripand hold the piece in the tool. I 1

A further object is a toothed dog and cooperating rack means associated with the handles of the pliers which may be operated by one of the handles first to progressively engage the toothed dog with the toothed rack by applying a force through one part of the dog and then to automatically shift the applied force through another part of the dog to apply the final positive gripping effort on the piece.

Another object is to eliminate accidental binding between the rack and dog by assuring proper inter-engagement of the teeth of these parts when the handles are operated to grip a workpiece.

Another object of the invention is to provide means which can quickly be adjusted to grip workpieces of different sizes and to thereafter apply a powerful gripping force to the pieces. 1

A still further object of the invention consists in pliers of the type disclosed which is simple of construction, is easy to operate and is positive in its action.

Other objects and advantages of this invention will become more apparent as thefollowing descriptions of two embodiments thereof progress, reference being made to the accompanying drawings in which like reference characters are employed to designate like parts throughout the same.

In the drawings:

FIGURE 1 is a side view of a tool embodying my invention showing the same partly in section longitudinally thereof and illustrating the positions of the jaws and intermediate mechanisms in gripping a workpiece;

FIGURE 2 is a view similar to that shown in FIGURE 1 and illustrates relative positions of the parts when the jaws are in substantially fully separated positions as is illustrated in broken lines and present these same parts in their relative positions when the handles are operated to bring the. jaws into a position about to grip the workpiece; I I 1 ,FIGURE3 is a side view of a tool embodying my invention illustrating a slightly modified construction, this view being similar to that shown in FIGURE 1 wherein the workpiece is gripped between the relatively movable jaws; and

FIGURE 4 is a view similar to that shown in FIGURE 3 showing the relative position of the parts in broken lines when the pivoted jaw is in relatively full open position with respect to the workpiece and in solid lines illustrating the approach of the jaws tothe workpiece but' slightly spaced therefrom.

In carrying out my invention, as illustrated in FIGS. 1 and 2, I provide a fixed jaw 1 which is integrally connected with a handle 2 extending rearwardly therefrom and which is substantially of U shape in cross section, said jaw having a working face 3 toothed for gripping engagement with a workpiece W.

A movable jaw -4 is pivoted at 5 to the rearwardly extending portion of the fixed jaw 1 at a point close to the head of the jaw and remote from the handle portion 2. The movable jaw 4 is formed with an 'arm 6 through which the pivot pin 5 extends, thus allowing the jaw 4 to move toward and away from the jaw 1 about the axis of the pin 5. The pivoted jaw 4 is also provided with a toothed work-engaging face, as at 7.

In further carrying out the invention, the movablebr pivoted jaw 4 is also formed with an arm 8 which extends rearwardly and in a direction diverging from that of the arm 6. A hollow handle 9 which is of inverted U shape is positioned along and in spaced relation and in substantially the same vertical plane as that of the handle 2 and extends forwardly toward the movable jaw, terminating at that end in a forward portion 10. A toggle comprising a single link or a pair of spaced apart parallel links 11 is pivotally connected at one end by means of a pin 12 to the arm '8 and is also pivotally connected by a pin 13 at the opposite end to the end portion ,10 of the handle 9.

In order to prow'de for quick selective preliminary adjustment between the jaws 1 and 4 to receive a workpiece of selected size, I provide a mechanism operable by the handle 9 and which includes a rack 16 which is rigidly secured to the handle 2 at points rearwardly'of the pivot 5 as at 17. This rack 16 is provided with a series of teeth 18 along its upper surface which are adapted to be engaged by mating teeth 19 formed in the lower surface of a dog 15. i

A coil spring 20 has one end attached to the movable jaw and its other end is attached to the dog 15 so that there is a normal tendency of the spring to draw the dog 15 and the arm 6 of the movable jaw toward each other. When an object W is gripped between the jaws 3 and 7, the spring 20 will be placed under increased tension as the thickness of the object is greater and under less tension where a thinner object is gripped. j

A transverse pin 22 is located in the forward end 10 of the handle 9 near the pivot 13 which carries the link 11 at the end of the handle. The dog 15 is preferably in the form of a flat plate having the teeth 19 formed along its lower surface for engagement with the teeth 18 of the rack 16 and is provided with a rather deep notch 23 which has at its inner end a rounded bearing surface indicated at 23' which is adapted to receive and have bearing engagement with the pin 22 when the parts are in the position shown in FIGURE 1. The pin 22 thus acts as a fulcrum for the handle 9 when it is in the bearing seat 23' and the dog is in the position shown in 3 FIGURE 1.

- which is carried in the forward portion of the handle 9 and projects through the opening 24 and operates therein. As shown in FIGURE 1, pin 28 is out of contact with the walls of the opening 24 which occurs when the pin 22 is seated in the bearing notch 23, as also shown in this figure. Thus, when the jaws are gripping a workpiece W, as illustrated in this figure, as a result of a squeezing pressure put upon the handles 2 and 9 to bring them into the position shown, the fulcrum of the handle 9 will be rotated on the axis of the pin 22 and an upward pressure will be exerted through the pin 13 and the toggle 11 to the pivoted jaw 4, thus bringing the jaw 4 into positive gripping relation with the workpiece W. At the same time the dog 15 is forced into positive gripping relation with the rack 16 through the respective teeth 19 and 18.

Due to the leverage arrangement through the forward end of the handle 9, the links 11 and the movable jaw 4 together with the relative positions of the centers identified by the

pins

22, 13, 12 and 5, a tremendous gripping pressure can be imposed through the jaws to the piece W as a result of a relatively light closing pressure placed manually on the handles 2 and 9.

When the workpiece W is to be released from the jaws of the tool, an upward movement of the handle 9 relative to the handle 2 and about the pin 22 will tilt the jaw 4 out of engagement with the workpiece. As the handle 9 is moved from the position shown in FIGURE 1 to the position shown in FIGURE 2 in solid lines, it will be noted that the pin 28, which heretofore has been out of contact with the

walls

25 and 26 defining the opening 24, will assume a position in contact with the

walls

25 and 26 adjacent their intersection 27. In this position the pin 22 will be withdrawn from the bearing seat 23 and an upward pressure is exerted on the dog 15 tending to tilt the dog in a clockwise direction so that its teeth 19 will progressively be disengaged from the teeth 18 of the rack 16. This is illustrated in solid lines in FIG. 2 and, under this condition, further upward movement of the handle 9 toward the broken line posi tion in FIG. 2 will cause the pin 28 to engage the intersection 27 and lift the dog 15 to the broken line position and will further withdraw the bearing surface 23 from engagement with the pin 22, thus shifting the movable jaw 4 to the broken line position in this figure.

The forward end of the handle 9 is formed with a surface 31 which is in contact with the stop pin 32 carried by the links 11 at a point intermediate the ends of the links to limit forward movement of the forward end of the handle relative to the links 11 only when the teeth 18 and 19 are disengaged and will therefore prevent too great a counterclockwise movement of the links during such disengagement of the teeth. It will be seen that as the handles 9 and 2 are relatively moved to a widely separated position as in broken lines in FIG. 2 and with the teeth 18 and 19 disengaged, the links 11 will be drawn to the right to open the jaws, while a rela tive movement of the handles to the full line position in FIG. 1 with the teeth 18 and 19 engaged will operate through the links 11 and the pins 12 and 13 to close the jaws about the workpiece W in positive gripping relation thereto.

As the handle 9 is brought from the broken line position in FIG. 2 downwardly to the position shown in full lines in FIG. 2, it will also be seen that the teeth 19 on the right hand end of the dog 15 will begin to engage the teeth 18 on the rack 16. At this point the pin 28 will move downwardly and out of engagement with the

walls

25 and 26 of the opening 24 and the pin 22 will be seated in the notch 23'. Continued movement of the handle 9 toward the handle 2 to the position shown in FIG. 1 will engage the jaws 3 and 7 with the work W and will move or tilt the dog 15 in a counterclockwise direction to progressively engage the teeth of the dog the tension of the spring 20. A further downward pressure on the handle 9 while the teeth 18 and 19 are thus engaged will exert a force through the links 11 about the pivot pins 13 and 12, respectively, to be transmitted to the jaws 3 and 7 to exert a powerful gripping action upon the workpiece held between the jaws. It will be observed that because of the pivotal relationship between the forward end of the handle 9, the links 11 and the arm 8 of the movable jaw whatever closing force is applied to the handle 9 will be considerably multiplied at the movable jaw and thus will permit a strong and positive gripping pressure on a workpiece held between the jaws by the application of merely a relatively light closing pressure on the handle.

When the teeth of the dog 15 are in mesh with the teeth of the rack 16, as shown in FIG. 1, movement of the dog is prevented in any direction and a downward or closing movement of the handle 9 will tend to keep the dog in this position by virtue of a downward pressure exerted through the pin 22 in the seat 23.

To release the workpiece held in the jaws of the tool, it is merely necessary to release the closing pressure on the handles whereupon the spring 20 will tend to unseat the dog 15 from the rack 16 and to withdraw the movable jaw from the workpiece, as shown in FIG. 2 resulting in an upward movement of the handle 9 to the full line position in FIG. 2 whereupon the workpiece may readily be removed from the jaws.

It will also be noted that because of the relationship of the pins 22, 28 and 13, a downward movement of the handle 9 from the broken line position in FIG. 2 will result in a progressive meshing of the teeth of the rack and the dog from right to left in FIG. 2, thus precluding the possibility of any of these respective teeth binding or obstructing the natural tendency of the dog to assume the full meshed position of the rack, as shown in FIG. 1.

The handle 9 is recessed along its top intermediate the handle proper and the forward end 31 to provide an edge or ledge 30 which engages the pin 30' as the handle is moved upwardly toward the broken line position in FIG. 2, and along which the pin 30' has sliding contact.

By such leverage means, the jaws are relatively separated with great ease against the tension of the spring 20 to receive a workpiece W by merely raising the handle 9 with one hand while holding the handle 2 with the other. At the beginning of such upward movement of handle 9, the teeth 18 and 19 will, of course, be disengaged.

Referring now to FIGS. 3 and 4 of the drawings, I have shown a slightly modified form of my invention which is substantially the same as that shown in FIGS. 1 and 2 but which shows the rack 16 as being secured in the lower handle 2 at its forward portion by means of the rivets or other securing means 17 in a substantially horizontal direction, whereas in FIGS. 1 and 2 the rack is positioned in a forwardly and upwardly inclined direction disposing the rack teeth along a line which is substantially parallel to the work gripping teeth 3 of the fixed jaw 1. The movable jaw 4 is pivoted to the fixed jaw, as at 5 and is provided with the forwardly converging arms 6 and 8 as in the previously described embodiment of the invention.

As described in connection with the embodiment shown in FIGS. 1 and 2, the dog 15 comprises a fiat member having a series of teeth 19 along its bottom edge for engagement with the teeth 18 of the rack 16. The coil spring 20 is attached at one end to the dog 15 and at its other end to the pivoted jaw 4 and normally urges these members toward each other. In a manner similar to that previously disclosed, the dog 15 is provided with an inwardly directed notch forming a crotch 23 at its inner extremity against which the pin 22 carried by the handle 9 has bearing engagement when the parts are in the position shown in FIG. 3. The pin 22 in this position serves as a stop to prevent forward movement of the dog 15 under" the tension of spring 20 butat the same time permits rotational movement of the dog about the pin22 as, for instance, when the parts are in the position shown in solid lines in FIG. 4.

A'pini28 operates in the opening 24 formed in the dog and as shown in FIG. 3 is located in a position removed from the point of intersection of the upper wall 25 and the side wall 26,this point of intersection being indicated at 27.

When the handle 9 is raised to operate the jaws 3 and 4 so that a workpiece W can be inserted therebetween, the pin 28 will ride up along the side wall 26 of the opening in the dog and will be seated, as shown in FIG. 4, at the crotch or intersection point 27, thus lifting the dog to the broken line position and completely out of engagement with the rack 16.

The pin 28 engages the intersection point 27 almost immediately upon a lifting of the handle 9, as shown in the full line position in FIG. 4 and, at the same time, the pin 22 begins to unseat itself from the crotch 23, thus permitting the dog 15 to be tilted in a clockwise direction against the tension of spring 20, as shown in full lines in FIG. 4. As the handle 9 is moved forwardly toward the position shown in broken lines, the dog will be lifted by the pin 28 completely out of contact with the rack and against the tension of the spring 20.

The handle 9 is provided with a forwardly and upwardly disposed abutment 40 which engages at its right hand portion the bridging stop 41 formed on the links 11 when the handles are separated as in FIG. 4, thus limiting counterclockwise movement of the links 11 about the pin 12.

It is to be noted in connection with both embodiments of the invention illustrated that the pin 28 moves along but out of contact with the side wall 26 of the opening 24 to the seating position at the intersection point 27 of the

walls

25 and 26. The load is thus transferred or shifted from the pin 22 to the pin 28 and as the handle 9 moves from the full line position in FIG. 4 to the dotted line position, this motion will be transmitted through the link 11 to raise the movable jaw 4 about the pivot 5 so that a workpiece W can be inserted between the jaws. When the handle 9 is lowered toward the handle 2 to put the workpiece in position, this movement will transmit the force through the forward end of the handle 9 to the links 11 and thence to the jaw 4 to rotate it in a counterclockwise direction so that the jaw will move toward the workpiece and finally engage and grip it. As the handle now approaches the'position shown in solid lines in FIG. 4, the teeth on the dog 15 will be brought into meshing engagement with the teeth on the rack 16 beginning at the right hand end of the dog and rack and, as the handle 9 is moved further toward closing and work gripping position, the pin 22 will enter its seat 23 in the notch and permit the dog to rotate still further to progressively engage its teeth with the teeth of the rack 16 in a progressive forward direction to the left. At the same time, the pin 28 will be unseated from the intersection point 27, as in FIG. 3.

In this form of the invention, I have illustrated a form of clamping means similar to that shown in my Patent No. 2,701,487, granted February 8, 1955, for releasably holding the arms 2 and 9 in closed position as illustrated in FIG. 3. Such means include clamping bar 42 which is of elongate form and which is provided with a transverse pin or stop 43 at its lower end bridging the slot 33' and which is provided with a head or bent over portion 32 at its other end. This member 42 opcrates in and along a narrow guide slot 33 formed along the handle 9 in the upper surface thereof and passes through the handle and into the lowerhandle 2 through the slot 33', the lower end of the member projecting through a wider slot 34 formed at the bottom .of the lower 'h andle and through which the pin 43 may pass. A pin 35 is transversely carried in the lower handle and limitsthe forward'rnovement of the member 42.

It will be noted that the clamping member 42 when in locking position to hold the handles in adjusted position will engage the rear end wall of the slot 34, as shown at 36 in FIG. 3 and the head 32 will engage along the upper surface of the handle 9 along the slot 33, as at 37, thus creating a clamping or binding action between the handles and with the pin 35. The length of the clamping member 42 is such that it will permit the handles 2 and 9 to be extended to their relatively full positions as shown in FIG. 4.

Various changes may be made in the details of con struction and arrangement of parts of the invention without departing from the spirit thereof or the scope of the appended claims.

I claim:

1. In a wrench, the combination with a handle having a relatively fixed jaw, of a relatively movable handle, a movable jaw pivotally connected with the movable handle and fixed jaw, and cooperating means carried on the handles movable for engagement and disengagement with each other when the handles are relatively moved toward and away from each other, respectively, said means including a toothed member on each handle, one of said toothed members being slidably and pivotally carried on one of the handles, means tensioning said one member, the other member being fixed to the other handle, and means on said one handle for imparting sliding and pivotal movement to said one toothed member when the handles are relatively moved.

2. In a wrench, the combination with a handle having a relatively fixed jaw, of a relatively movable handle, a movable jaw pivotally connected with the movable handle and fixed jaw, and cooperating means carried on the handles movable for engagement and disengagement with each other when the handles are relatively moved toward and away from each other, respectively, said means including a toothed member on each handle, one.

of said toothed members being a dog that is slidably and pivotally carried on one of the handles, means tensioning said one member, the other member being fixed to the other handle, and means on said one handle for imparting sliding and pivotal movement to said one toothed member when the handles are relatively moved, said last named means comprising first and second pins carried by said movable handle and engageable with first and second seats in said dog, said first seat being formed by an opening in said dog, one of said pins operating within the opening to enter and leave said seat, the second seat formed in a wall of said dog and said second pin enters and leaves said second seat but out of phase with the movement of the first pin.

3. In a wrench, the combination with a handle having a relatively fixed jaw, of a relatively movable handle, a movable jaw pivotally connected with the movable handle and fixed jaw, a link pivotally connecting at its respec tive ends the movable jaw and the movable handle, and cooperating means carried on the handles movable for engagement and disengagement with each other when the handles are relatively moved toward and away from each other, respectively, said means including a toothed member on each handle, one of said toothed members being a dog that is slidably and pivotally carried on one of the handles, means tensioning said one member, the other member being fixed to the other handle, and means on said one handle for imparting sliding and pivotal movement to said one toothed member when the handles are relatively moved, said last named means comprising first and second pins carried by said movable handle and engageable with first and second seats in said dog, said first seat being formed by an opening in said dog, one of said pins operating within the opening to enter and leave said seat, the second seat formed in a wall of said dog and said second pin carried by the movable handle enters and leaves said second seat but out of phase with the movement of the first pin, said link having a transverse stop portion between its ends and engageable with the adjacent end of the movable handle to limit pivotal movement of the link as the handles are relatively moved in the direction of separation.

References Cited in the file of this patent UNITED STATES PATENTS Robbins Dec. 3, Robinson Apr. 20, McCullough Sept. 12, McGill Nov. 29, Prentice Nov. 11, Ortman Feb. 8, Miller Sept. 29,