US2639887A

US2639887A - Nail pulling device

Info

Publication number: US2639887A
Application number: US211220A
Authority: US
Inventors: Walter N Henry
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-02-16
Filing date: 1951-02-16
Publication date: 1953-05-26
Anticipated expiration: 1970-05-26

Description

May 26, 1953 w. N. HENRY 2,639,887

NAIL PULLING DEVICE Filed Feb. 16, 1951 2 Sheets-Sheet l as 80 99 g 93 92/M 28 1N VEN TOR.

WALTER N. HENRY ATTORNEYS Patented May 26, 1953 UNITED STATES PATENT OFFICE NAIL PULLING DEVICE Walter N. Henry, Dayton, Ohio Application February 16, 1951, Serial No. 211,220

11 Claims.

bedded, particularly where it is desired to leave the surface material sufiiciently undamaged for reuse.

Such work is ordinarily done by means of hand tools, the use of which has a tendency to mar and break the wood so that it cannot be used again. Because of the physical strength necessary to use the tools, it is ordinarily required to be done by men. The amount of work that can be done by each workman each day by the ordinary method, is, moreover, relatively limited.

It is accordingly one of the principal objects of the invention to provide a power-operated tool for quickly and easily pulling nails and the like from a surface in which they are embedded and with minimum damage to the surface.

Another object is to provide power-operated apparatus for opening boxes, crates and the like on a quantity basis in a substantially shorter unit time than heretofore accomplished in order to increase the volume of work which may be done in a given time by each operator.

It is a further object of the invention to furnish a device for opening boxes, crates and the like operated by power rather than by muscular strength, so that it may be used in industry by women and boys. I

Additional objects of the invention are to provide a power-operated nail pulling device which is relatively light in weight, which is relatively simple yet strong and certain in operation, and which may be produced at reasonable cost.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. I

In the drawings Fig. 1 is a side elevation, partly broken away Fig. 5 is a detail perspective view-on an enlarged scale of one of the jaw members of the device;

Fig. 6 is a detail perspective view of a part of one of the jaw-operating members of the device;

Fig. 7 is a section on the line l'! of Fig. l;

Fig. -8 is a fragmentary section showing the jaws embedded in a surface surrounding a nail to be pulled at the beginning of the jaw-closing movement;

Fig. 9 is a fragmentary section similar to Fig. 8

showing the jaws closed on the, nail, which is partially withdrawn;

Fig. 10 is a side elevation with the casing in section showing the relative positions of the parts at the conclusion of a nail pulling operation; and

Fig. 11 is an elevational view of another form of construction of the device, having a self-contained power source.

Referring to the drawings, which illustrate preferred embodiments ,of the invention, the device as shown includes an outer casing 20, shown as in two parts, and an'inner casing 2|, to which are affixed respectively handles 22 and 23, handle 23 projecting through a suitable slot 24 in the outer casing and being afilxed at its upper end only in order to extend over the outer casing. A rotatable shaft 25 having threaded portion 26 is mounted within inner. casing 2| and is adapted to be'attached to a power source, not shown, by a flexible driving conneotion 2'! or other suitable means. The drive shaft 25 is supported at its upper end by a ball-bearing 28, and at its lower end by an enlarged portion 30 in a bushing 3| press-fitted into a web 32 in the interior of inner casing 2| and retained in position by a further enlargedportion 33 of the shaft. Bearing 28 may be press-fitted into a suitable aperture in the top 34 of inner casing 2| and held in place by cap 35 retained by screws 36 or other suitable means, and as shown, bearing 28 is preferably constructed to serveas both a radial and thrust bearing for shaft 25.

A hammer member 40 is mounted within inner casing 2| for rotational and reciprocating movement in cooperation with an anvil member H and is operatively connected with shaft 25 by means of a slot 42 which receives a corresponding flattened end portion 43 of the shaft. The hammer member may thus slide axially on the shaft but will be rotated by it, and it is normally biased downward by spring 44 surrounding areduced;

portion of thehammer memberand compressed between the enlarged-portion 33 on shaft 25 and an enlarged head portion. of the hammer memher. The upper end portion of anvil member 4| is also enlarged so that both members fit in guided relation within inner casing 2|, and both the hammer member and anvil member are provided on their adjacent faces with helically curved cam surfaces to and 5!, respectively, adapted to cooperate with each other alternately as the hammer member 49 is rotated to force the latter axially of casing 2| and against spring 44 away from anvil member 4! and then to release the hammer and permit it to strike the anvil under the urging of spring 44.

The anvil member d] includes a lower portion splined for sliding movement in the reduced lower end portion 52 of inner casing 2i. d A carrier member 53 for the nail pulling jaws '55 is secured to the lower end of the anvil, as b -y the threaded connection at 58, for movement therewith as a unit, and these parts are normally biased downwardly by the spring 5'! seating against shoulder portions 'on the member 53 and inner casing 2| 'as clearly shown in Fig. 2. The lower end of carrier member 53 is slotted to form a fork for receiving jaws '55, which are pivoted therein by means of pins 58 in bores '59 and are normally biased to open position by a spring 60 as shown in Fig. 2, and the jaws may be provided with serrated nail gripping edges 61 (Fig.5).

The jaws 55 are adapted to be closed-into nail gripping position by an inwardly tapered collet portion '65 at the lower end of outer casing. 26 which operates the jaws through a pair of fingers 6t pivoted at their upper ends by pins 61 in slots at either side of-casingzl. At its lower end, each finger 86 (Fig. 6) carries a roller 70 for reducing friction with the collet 65, and the inner; side of the lower end of each finger 66 is channeled at H for guided engagement with lugs 'or pads I2 on the backs of the jaws 55 which fit slid'ably within the channels '11. Thus if outer casing is moved 'down'wa'rdlywith respectto the inner casing, the'collet 65 will press fingers ts inwardly against jaws 55 and thereby force the nail gripping lower portions of the J'aw's towards-each other and into grippingposition.

A selectively operable driving connection is provided for causing relative axial-movement of the inner and outer casings to efiect closing of jaws 55 as described, and thereafter to cause the nail gripped in the 'closed'jaws to be withdrawn. This connection includes a partly hollow'block l5 straddling shaft and having a threaded halfcircular portion 17 adapted to engage the thread ed portion 26- ofshaft "25-. 'At one end block 5 5 includes upwardly extending arms '18 in which a lever 79 is pivotally mounted at 80-, "and at itsopposite end block 15 includes a 'pinp ruon 31-. Block i5 extends through projections '82 and 83 on the-wallof casing 20, projection sensin pro= vid'ed with a cap- 84. A'spri'ng B5 is mounted on pin 81 between the end ofprojection 83 and a washer 86 held on the end of pin B'I bymearis such as a cotter pin 8l to bias block 15 to the right as viewed-in Fig. l and thus to disengage threads 11 from-the threaded pdrtion ze-o'r the shaft.

A b-lock eo is slidably-r'eeeived within block it. and. it includes a pin portion 91 which extends through a slot "92 in lever 79 and th-rough a plate 93 held. between the arms TB- outwardly of lever 79. At its ihnereride, block 90 "inelude's'ath half circular portion 94 adapted to engage the threads '25. on shaft '25. A 95 is mounted on pin'9 I between plate 93 and a wa er J6 andcotter. pin 911011 pin. 9 I to bias block- 90 normally:

' shait 25 revolving, the blocks will be caused to travel along the shaft and to carry outer casing 20 downwardly with respect to inner casing 21. (lasing 2l has slots I00 on opposite sides to receive blocks (5 and 90 during this movement, as well as the slot 24 for similarly receiving handle 23 as described.

"In operation, the operator holds the device in position substantially perpendicular to the surface in which the nail is embedded, with the open jaws on either side of A the head of the nail. Slight pressure forces the jaw assembly and a'nvil 'member 4! axially inward against the pressure of spring 5?, bringing the cam surfaces 50 and '5! of hammer M8 and anvil il into contact. As hammer member 40 is rotated rapidly by shaft 25, the cam surfaces cooperate first to force it away from the anvil member, compressing spring M, as shown in Fig. 2, and then to release it to be driven sharply against anvil member 4| by the release of this spring, producing a reciprocating hammering action to force jaws 55 into the surface against which the jaws rest as shown in Fig. 8 in position to grip the nail when thejaws are closed.

In order to close the jaws around the nail and to .extract it, the operator then causes outer casing 28 to move axially of inner casing 2| by pressing the free end of lever '59 toward the casing, causing blocks 75 and EN! to move inwardly into cooperative engagement with the threaded portion 26 of shaft '25 and to travel downward along the rotating shaft as described, outer casing 20 serving during this movement both as a jaw-closing member and as a withdrawing member. As casing 20 moves downward, the jaws are caused to close into gripping relation with the nail by the collet 65 as shown in Figs. 8 and 9. As it continues its downward inotion, its lower end comes into contact with the surface surrounding the nail and causes inner casing 2| and the closed jaws to move away from such surface until the nail is fully withdrawn (Fig. 10). The length of threaded portion 26 should he such that the closed blocks 75 and 90V will ride on the lower end thereof when withdrawal is completed. The operator then, by releasing lever T5, allows the blocks to be separated by the action of springs and 95, and returns outer casing 20 manually by means of

handles

22 and 23 to the position of Fig. 1. As jaws 55 are released from the pressure of collet 65 they are opened by spring 50, and the withdrawn nail drops out.

The area of the lower end. of casing 20 pressing against the surface surrounding the. nail while it is being withdrawn is sufficiently broad that there is little if any tendency for it to mark the surface. Additionally, all of the force used in extracting the nail is exerted outwardly, so that any tendency to push the nail sidewise and thus to increase friction during extraction, as is the case with the hand tools normally em; ployed, is avoided. There is accordingly a minimum tendency to mar, break or otherwise to .spoil thew'ood or other suifacein whichthe nail is vimbedded, permittingsuch material to be reused. Thus use of the invention will greatly speed up the operation of withdrawing nails and permit substantial increase in the rate of work of an operator. Furthermore, since the physical strength necessary for operating the device is substantially only that necessary to hold it in position and it is relatively light in weight, only slight physical strength is required for its use, and it may easily be used by women and boys.

It is preferable that hammer member 40 and anvil member 4| should operate in a lubricating bath, and inner casing 2| is accordingly shown as being formed in two sections connected by a threaded connection at [M to provide for adding lubricant when necessary, and also for simplicity in assembly. It may be advisable also for the lower portion of outer casing 20 to be made from steel or other material different from that of the upper portion, and as noted, outer casing 20 is similarly shown as being in two sections connected by a threaded connection at I02.

It is apparent that the force of the blows by hammer member 40 on anvil member 4| will depend on such factors as the weight of the hammer member, the strength of the spring 44, the length of the stroke, and the speed of rotation of shaft 25. It has been found in practice that a hammer member weighing slightly more than A; pound, rotated at a speed of approximately 1000 R. P. M. and with two earns 50 and 5| on each of the respective cam surfaces having a depth between their high and low points of approximately one-half inch, in cooperation with a spring exerting a pressure of approximately 60-80 lbs. when compressed, gives satisfactory results.

Fig. 11 shows a nail .pulling device similar..to that described in connection with Figs. 1 to'lO and including similar outer and inner casings l20 and IN respectively. However, instead of a flexible connection to the drive shaft from an external drive source, Fig. 11 shows a motor I22 mounted directly on the upper end of the inner casing, either an electric or air motor being satisfactory. The construction and operation of this form of the invention is otherwise substantially the same as already described in connection with Figs. 1 to 10.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

l. A power-operated nail pulling device comprising a casing, an anvil movable in said casing, nail-gripping jaws carried by said anvil and projecting from said casing, a drive shaft rotatable in said casing, means for connecting said drive shaft to a power source for rotation thereby, a driving member for said anvil mounted for reciprocation in said casing in response torota-- tion of said drive shaft for driving said anvil in a direction to force said jaws into the surface surrounding a nail to be pulled, a withdrawing member carried by said casing and extending adjacent said jaws in initially spaced relation with said surface, means for causing the closing of said jaws to grip said nail, and means for selectively connecting said drive shaft to said withdrawing member for causing relative movement thereof toward said surface-and corresponding movement of said jaws in gripping relation with said nail away from said surface.

2. A power-operated nail pulling device comprising a casing, an anvil movable in said cas-- ing, nail-gripping jaws carried by said anvil and projecting from said casing, a drive shaft rotatable in said casing, means for connecting said drive shaft to a power source for rotation thereby, a driving member for said anvil mounted for reciprocation in said casing on rotation of said drive shaft for driving said anvil in a direction to force said jaws into the surface surrounding a nail to be pulled, a withdrawing member carried by said casing and extending adjacent said jaws in initially spaced relation with said surface, means operably connected with said drive shaft for causing the closing of said jaws to grip said nail, and means operably connected with said drive shaft for causing relative movement of said withdrawing member toward said surface and corresponding movement of said jaws in gripping relation with said nail away from said surface.

3. A nail pulling device comprising an anvil member, normally open nail-gripping jaws carried by said anvil member, a hammer member adjacent said anvil member and reciprocable with respect thereto, a drive shaft, means connected with said drive shaft for driving said hammer member against said anvil member in a direction to force said jaws into the surface surrounding a nail to be pulled, a withdrawing member adjacent said jaws and initially spaced from said surface, said withdrawing member having a portion adapted on movement thereof toward said surface to close said jaws to grip said nail, said withdrawing member having another portion adapted on movement thereof toward said surface to abut against said surface and to press said jaws in gripping relation with said nail away from said surface, and means for selectively connecting said withdrawing member with said drive shaft.

4. A nail-pulling device adapted for use with a power source, comprising a rotatable shaft adapted to be connected to said power source, a driving member operably connected with said shaft for rotation thereby, an anvil member adjacent said driving member, normally open nailgripping jaws carried by said anvil member, means for biasing said driving member toward said anvil member, means on said driving member and said anvil member adapted to cooperate with said biasing means on rotation of said driving member for driving said anvil member in a direction to force said jaws into the surface SUI",

rounding a nail to be pulled, means for selectively closing said jaws in gripping relation with said nail, means movable relatively to said jaws for direct engagement with said surface to force said jaws and said nail away from said surface, and means for selectively connecting said movable means with said power source for causing said relative movement of said jaws and said movable means.

5. A power-operated device for pulling nails comprising a rotatable shaft adapted to be connected to a power source, a hammer member on said shaft adapted to rotate therewith and to move axially thereon, an anvil member adjacent said hammer member, a plurality of normally open nail-gripping jaws supported for movement with' said anvil member, means biasing said hammer member toward said anvil member, complementary portions on said hammer member and;

aeeaeer said anvil member adapted to cooperate with said biasing means to effect reciprocating move-- ment of said hammer member with respect to said anvil member upon rotation of said shaft to drive said jaws into the surface adjacent a nail to be pulled, a withdrawing member adjacent said jaws in initially spaced relation with said surface, means for operation by said shaft to close said jaws in gripping relation with saidnail, means for operation by said shaft for cansing relative movement or said withdrawing member toward said surface and corresponding move merit of said closed jaws and said nail awayfro'm said surface to extract said nail therefrom, and means for releasably connecting said shaft with said jaw-closing means and with said withdrawing member.

'6. A power-operated device for pulling -nails comprising a rotatable shaft adapted. to be con nected to a power source, a hammer member on said shaft adapted to rotate therewith and to move axially thereon, an "anvil member adjacent said hammer member, a plurality of normally open nail-gripping jaws supported for movement with said anvil member, means biasing said-hammer member toward said anvil member, comp-1ementary cam portions on said hammer member and said anvil member adapted t'ocooperate with said biasing means to effect reciprocating movement of said hammer member with respect to said anvil member upon rotation of said "shaft to drive said jaws into the-surface adjacent a, nail to be pulled, a casing supporting said shaft "and said hammer member and anvil member, means slidable on said casing forming a collet for closing said jaws in gripping relation with 'saidnai-l, and means forming a selectively operable driving connection between said shaft and said collet causing said collet to move first into jaw-closing relation with said jaws and thereafter to move beyond said jaws and against said surface to force said jaws and nail away from-said surface.

7. In a power-operated nail puller, a casing, a rotatable shaft in said casing adapted to be connected to a power source, a hammer member on said shaft adapted to rotate with said shaft and to move axially thereon, an anvil member in said casing adjacent said hammer member, normally open nail-gripping jaws carried by said anvil member, means biasing said hammer member toward said anvil member, means cooperatiing with said biasing means to effect reciprocating movement of said hammer member with respect to said anvil member upon relative ro't'ative movement of said hammermember and said anvil member to drive said nail-gripping jaws into the surface adjacent a nail to be pulled, jawclosing means supported by said casing for first closing said jaws to grip said nail and for thereafter forcing said jaws and said nail away from said surface to withdraw said nail, and selectively operable means for connecting said jaw-closing means with said shaft.

8. A nail pulling device adapted for use with a power source, comprising a rotatable shaft hav ing a threaded portion thereon, means for connecting said shaft to said power source, axhammer member on said shaft adapted to rotate therewith and to move axially thereon, an anvil member adjacent said hammer member, normally open nail-gripping jaws supported for movement with said anvil member, means for effecting reciprocating movement of saidshammer member with respect to said anvil member upon. rotation of said shaft "to drive said Jaws intothe.

serrate adjacent a hall to be pulled, a member" for "closing said jaws-supported for axial movement with respect to said shaft, threaded members supported on saidclosing member for movement therewith and normally spaced from said shaft, and means for bringing said threaded members into cooperative engagement with said threaded portion of said shaft for causing said axial movement of said closing member to close said jaws on said nail and to press said closed jaws and nail away from saidsurface.

9. A power-operatedhail-pulling device comprising an outer casing, an inner casing adapted for aide-l movement within said outer casing, a rotatable shaft within said inner casing adapted to be connected to a powerseurce, an anvil supported in-said inner casing, for limited axial move ment therein, normally open nail-gripping jaws supported by said anvil, a hammer adjacent said anvil mounted for reciprocating axial movement onsaid shaft and adapted to rotate with said shaft, means biasing said hammer toward said anvil, earn means on adjacent faces of said hammer and said anvil-cooperating with said biasing means to effect reciprocating movement of said.

hammer toward and away from said anvil upon rotation of said shaft for driving said jaws into the'surfacesurrounding a nail to be pulled, means for "effecting relative axialimo'vement of said outer casing andsaid inner casinguponrotation of said shaft, and means for causing said jaws to grip and to withdraw said nail upon said relative axialm ovement'o'f saidouter andsaid inner casings.

10-. A po'wer-operated'inail puller comprising a casing, a rotatable shaft insaid-cas'ing, saidshaft having a threadedpdfiion thereon, means for connecting said shaft with a power source, a hammer member on. said shaft adapted for axial movement thereon and for rotation therewith, an

anvil. member. in said-casing adjacent said hammer member, saidiharnmer 'member and said anvil member including-cooperating cam surfaces on adjacent facesxthereof, normally open nail-gripping ijaws carried-by said-anvil member, means biasing said hammer member toward said anvil member and: adapted to cooperate with said. cam surfaces-for effecting reciprocating axial movement of said -hammerimember with respect to said anvil member upon rotation'of said shaft to drivesai d openinailagripping jaws into the surface surrounding anail to be pulled, a member carried by said casing initially spaced relation with said surface adapted to move axially of said shaf-ttoward-said surface-for closing said jaws, said member having a portion thereof adapted on said axial movement to press against said surface and to force said jaws in gripping relation with saidv nail away from said surface, and threaded means carried by said axially movable member, for releasable engagement with said threaded portion of said shaft'to cause said axial movement of said movable member.

11. In a, power-operated -nail puller, a casing, a rotatable shaft in said casing adapted 'to be connected toatpower source andhawihgathrw'ded portion. thereon, aYhar-nmer member on said shaft adapted'to rotate withssaid shaft and to move axially thereon, an anvil member in said casing adjacent said hammer member, normally open nail-gripping meanscarried by said anvil member, means biasing, said hammer member toward said anvil member, means cooperating with said biasing means .to, effect reciprocating movement of saidfhammenmember with respect tosaid anvil member upon relative rotative. --movement of said hammer member and said anvil member to drive said nail-gripping means into the surface adjacent a nail to be pulled, a collet supported by said casing for axial movement with respect to said shaft to close said gripping means, blocks supported for movement with said coilet and normally spaced from said threaded portion of said shaft, said blocks having threaded portions for cooperative gripping engagement with said threaded portion of said shaft on movement into engagement therewith, and a lever for efiecting movement of said blocks into said cooperative gripping engagement with said threaded portion of said shaft for causing said axial movement of said coliet to close said nail-gripping means on said nail and to press said closed nail-gripping means away from said surface to withdraw said nail.

WALTER N. HENRY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 754,754 Dudly Mar. 15, 1904 2,570,915 Buck Oct. 9, 1951-