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Publication numberUS2384408 A
Publication typeGrant
Publication dateSep 4, 1945
Filing dateSep 21, 1944
Priority dateSep 21, 1944
Publication numberUS 2384408 A, US 2384408A, US-A-2384408, US2384408 A, US2384408A
InventorsWilliam B Warren
Original AssigneeFisher Scientific Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Safety tongs
US 2384408 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Sept. 4, 1945. w, B. WARREN SAFETY TONGS Filed Sept. 21, 1944 2 Sheets-Shee t 1 [NV TOR; "nu mm (8. M

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Sept. 4, 1945. w. B. WARREN SAFETY TONGS Filed Sept. 21, 1944 2 Sheets-Sheet 2 cvrrwsssss.

Patented Sept. 4, 1945 SAFETY TON GS William B. Warren, Pittsburgh, Pa., assignor to Fisher Scientific Company, Pittsburgh, Pa., a corporation of Pennsylvania Application September 21, 1944, Serial No. 555,084

1 Claim.

This invention relates to safety tongs such as are used in laboratories for handling beakers, flasks, evaporating dishes, and the like.

It is customary to make safety tongs with their gripping arms forming extensions of their handles or jaws which are pivotally connected at their front ends on a vertical pivot, like shears. Therefore, in order to grip a beaker, for example, the jaws must be squeezed horizontally together. The position that the hand generally takes at this time is such that it is not easy to twist the wrist to pour out the contents of the beaker.

It is among the objects of this invention to provide safety tongs which are more convenient to handle than those known before, and which make pouring easier to accomplish and safer.

In accordance with this invention a pair of jaw-like handles, arranged in superposed relation, are pivotally connected together at one end which will be referred to as their front end. Projecting downwardly from the front end of the lower jaw is an actuating member that extends between the rear ends of a pair of laterally spaced gripping arms which project forward from the front ends of the jaws. The rear ends of these arms are pivotally connected to the bottom of the upper jaw so that the arms can swing toward and away from each other. Rigidly connected to the rear end of each of the arms is an arm-swinging member. These two members project toward each other and are adapted to engage the rear side of the actuating member. Consequently, when the jaws are grasped in the hand and the lower jaw is swung upwardly, the actuating member projecting from it is swung rearwardly. This moves the arm-swinging members rearwardly to swing the gripping arms toward each other so that they can grasp an article which they may be straddling. Preferably, the actuating member and the arm-swinging members are pins with the adjacent ends of the arm-swinging members crossing each other and engaging the actuating pin at vertically spaced points.

The preferred embodiment of the invention is illustrated in the accompanying drawings in which Fig. 1 is a side View of my safety tongs; Fig. 2 is a front end view thereof; and Figs. 3 and 4. are bottom views of the tongs showing them open and closed, respectively.

Referring to the drawings, an upper jaw I is provided with a, downwardly opening recess 2 extending nearly its full length. The front end of this jaw is widened out to provide on opposite sides of the recess solid side portions having flat lower surfaces 3,. Inserted in the front end of the recess and normally extending downwardly and rearwardly therefrom is a lower jaw 4. The front or upper end of this jaw is pivotally connected to the upper jaw by a horizontal pin 5 extending through them. The two jaws thus form a handle that can be held in the hand where thejaws can be closed by squeezing them together.

The rear ends of a pair of laterally spaced gripping arms I are pivotally connected to the front end of the upper jaw by means of vertical pins 8 projecting downwardly from the flat lower surfaces 3 on both sides of the lower jaw. The two arms, which extend forward away from the handle, can thus be swung toward and away from each other. To normally keep the arms spread apart, their rear ends are connected by a coil spring 9 attached to lugs I0 projecting from the arms behind the vertical pivot pins 8. As will be seen in Fig. 1, the main body of each arm is disposed at a lower level than its rear end. This lowers the center of gravity of the article grasped by the tongs relative to their handle, and thus makes it easier to handle. The article-engaging ends of the arms may be provided with a contour in vertical cross section which is best adapted for grasping the type of article for which any particular instrument is designed. The arms preferably are covered by asbestos sleeves l I to insulate them to some extent from the heat of the object held by them;

In order to swing the arms toward each other, the front end of the lower jaw is provided with a down-turned portion from the bottom of which an actuating pin I3 projects. Engagement of this portion with the front wall of recess 3 limits opening of the jaws. The rear side of pin I3 engages the front sides of a pair of horizontal pins I4 and I5 projecting toward each other from the sides of the rear ends of the arms. These last two pins are disposed one above the other, as shown in Fig. 2, so that their outer ends can cross or overlap. Arm-swinging pins I4 and I5 are held against the actuating pin by the tendency of the coil spring to swing the arms apart, as shown in Fig. 3.

When the lower jaw is squeezed upwardly toward the upper jaw, it swings actuating pin I3 back, as shown in Fig. 4. The actuating pin presses against the arm-swinging pins and therefore moves them back. This movement of pins I4 and I5 swings the gripping arms on their pivots and thereby moves their outer ends toward each other so that they can hold an object, such as a beaker, between them. When the lower jaw is released, the actuating pin moves forward and the coil spring swings the gripping arms apart.

By the use of a handle in which pressure is applied vertically, instead of horizontally, to move the gripping arms together, the hand that holds the handle can take a natural position from which it readily can be rotated in either direction for pouring out the; contents of the beaker or other receptacle held bythe tongs. This advantage of my tongs is important, as it makes pouring easier and safer because there is less likelihood of spilt-- ing.

According to the provisions of the patentstatutes, I have explained the. principle and con-- struction of my inventionand' have illustrated:

and described what I now consider to IGDIGSBl'llSflil-ibest embodiment. However,, I desire to have, it. understood that, within the scope oftlie 'alppen'ded' claim, the invention may be practiced otherwise, than as specifically illustrated and described.

I claim:

Safety tongs comprising normally open upper and lowerhandle jaws pivotally connected at their front ends, an actuating pin projecting downwardly from the front end of the lower jaw, a pair of laterally spaced gripping arms projecting forward from the front ends of the jaws, means pivotally connecting the rear ends of said arms to, the bottom ofthe upperjaw on opposite sides of said pin, a coil spring connected to the rear ends of said arms behind said pivoting means for swinging the front ends of the arms apart; and a pair of pins projecting toward each other from the rear ends of the arms, the adjacent ends of saidpair of pins being superposed and crossingeach: other in contact with the rear side of said actuating pin for swinging the arms toward each other when the actuating pin is swungrearwardly by the lower jaw.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2641497 *Aug 26, 1950Jun 9, 1953Thomas John LLifter for utensils and the like
US4156959 *Dec 17, 1975Jun 5, 1979Weisenburger AExpander device
US4543032 *Mar 2, 1983Sep 24, 1985International Business Machines CorporationRobot manipulator with automatically changeable finger tools
US7371242 *Feb 4, 2004May 13, 2008Scott WadsworthThree pronged lever-action castration tool
U.S. Classification294/28, 81/348, 81/488, 81/3.44, 422/549
International ClassificationB01L9/00
Cooperative ClassificationB01L9/50
European ClassificationB01L9/50