US2891249A - Fastener gripping device for a power actuated tool - Google Patents

Description

2 Sheets-Shee t 1 INVE/V TORJ R. J. KOPF ETAL Rowland 1. K0

R gel Mara/l FASTENER GRIPPING DEVICE FOR A POWER ACTUATED TO'OL June 23, 1959 Fild Jan. 12, 1955 ATTORNEYJ 2 Sheets-Sheet 2 INVENTOR.

A TT'O ENE YS u 1959 R. J. KOPF' ETAL FASTENER GRIPPING DEVICE FOR A POWER ACTUATED 'I'OOL' Filed Jan. 12; 1955 I ROWLAND J. KO BY EOGEE MARS Afifl? A inn/4 ////AA Patented June 23, 1959 FASTENER GRIPPING DEVICE FOR A POWER ACTUATED TOOL Rowland J. Kopf, Rocky River, andRoger Marsh, Hudson, Ohio, assignors, by mesne assignments, to Olin Mathieson Chemical Corporation, a corporation of Virginia Application January 12, 1955, Serial No. 481,470

12 Claims. (Cl. 1--44.5)

.This invention relates to improvements in power actuated tools and more particularly to a power actuated tool and/or driveable unit therefor adapted to have a driveable unit restrained against free flight.

One of the objects of the present invention is to provide a power actuated tool and/or a driveable unit wherein a fastener driven thereby cannot escape into free flight.

A further object of the present invention is to provide a power actuated tool for driving a fastener into a workpiece with means for stopping said fastener and then permitting axial withdrawal of said tool from the fastener. i i

A further object of the present invention is to provide a tool, as set forth in the previous paragraph, wherein said meansis inertia operated and/or stops said fastener when its, piercing portion emerges a predetermined distance from the tool.

A further object of the present invention is to provide a tool with a driveable fastener, carrier having means for easy assembly and disassembly of a fastener therewith while preventing free flight of said fastener from said tool and not requiring any manual or automatic actuation of engaging devices during assembly or disassembly.

A further object of the present invention is to provide a power actuated tool characterized by its greater safety in operation, structural simplicity, more satisfactory driving of fasteners thereby, and ease of operation.

Other features of this invention reside in the arrangement and design of the parts for carrying out their appropriate functions.

Other objects and advantages of this invention will be apparent from the accompanying drawings and description and the essential features will be set forth in the appended claims. t t i In the drawings,

Fig. 1 is a side elevational view of a simplified powder actuated tool having its muzzle pressed against the workpiece and having a driveable unit loaded in its barrel;

Fig, 2 is a longitudinal sectional view through the barrel'andthe front end of the driveable unit in Fig. 1;

Fig. 3 is a longitudinal sectional View taken along the line 3-3 of Fig. 6 of the driveable unit after the fastener arresting device has prevented free flight of the fastener carrier piston and fastener carried thereby;

'jFig. 4 is a side elevational view of the fastener in Fig. 3 after the tool has been removed therefrom;

Fig. Sis a longitudinal sectional view of the present invention, in the barrel and tool disclosed in the hereinafter mentioned copending application, while ijEig. 6 "s a transverse sectional view taken along. the line 66 of Fig. 3.

Beforethe tool here illustrated is specifically described, it is to be understood that the invention here involved is noti limited to the structural details or arrangement of parts 'here shown since tools. embodying the present invention may take various forms. It also is to be under- Stood that the phraseology or terminology herein employed is for purposes of description and not of limitation since the scope of the present invention is denoted by the appended claims.

Those familiar with this art will recognize that this invention may be applied in many ways. The invention,

- in its broader aspects, includes all types of power actuated tools with power actuation for such fastener driving tools including hydraulic, pneumatic, electromagnetic, explosive powder charge, or any other suitable type power. However, only the explosively actuated tool embodiment is described in detail herein. Tool 10 in Fig. 1 is adapted to drive or set a fastener into the flat surface of a workpiece 11 comprising for example a covering 12 to be secured to a base portion 13.

Explosively-actuated tool 10 includes a member with a passageway for confining and driving, such as the bore of barrel 15, so that an explosive charge set off by trigger 16 in any suitable manner can drive a driveable unit 20 through the barrel or along any suitable passageway from the breech or entry end toward the barrel muzzle or discharge end so as to drive a piercing portion thereof through the workpiece 11. An example of an explosively-actuated tool on which the present invention may be used is disclosed in the copending U.S. patent application entitled EXplosively-Actuated Tools, Serial No. 355,034, filed on May 14, 1953, by R. J. Kopf, R. W. Henning and R. Marsh, to which reference may be had for further disclosure if necessary. Only the barrel, hand grip and trigger of a simplified version of said tool are shown in Fig. l and only the barrel of this simplified version is shown in Figs. 2, 3 and 6, while a portion of the tool from this aforesaid copending application is shown in Fig. 5. i

In a conventional explosively-actuated tool, the fastener is driven through the barrel and out of the muzzle at high speed, so that if the tool barrel is not properly set against the workpiece or if the fastener is fired into unsuitable material, the fastener may escape into the air in free flight so as to become a dangerous missile. It is therefore desirable for safety reasons to prevent the escape of the fastener into free flight. This difiiculty may occur when using a conventional tool if the operator attempts to fire the tool into the air instead of against the workpiece, if the operator attempts to fire the tool into a workpiece having insuflicient penetration resistance so that the fastener travels completely through the workpiece to escape into free flight, if the operator fires the tool with the barrel axis substantially less than 90 with respect to the surface of the workpiece so that a ricochet occurs, etc. The present invention has solved these, as well as many other problems by having a driveable unit, including the fastener as well as a captive rain or fastener carrier piston, driven through the tool barrel by the explosively actuating gases with this ram prevented by appropriate means from escaping completely from the barrel. Hence, the fastener cannot escape into free flight tobecome a dangerous missile.

ln the present disclosure, captive driveable unit 20 includes a fastener 21 detachably connected to a fastener carrier, such as the element 22 here shown, which is designated herein as piston, driving head or captive ram. Piston ZZcomprises a body including an integrally connected head 23a and forwardly extending stem 23b to which is screwed a cap 24 with an outwardly and rear- Wardly tapered bore 24a forming a blind bore extending inwardly from the front of piston 22. Piston 22 inagainst the taper of bore 242: to fastener gripping position for detachably securing fastener 21 to piston 22 but normally biased rearwardly to a normally released position by suitable resilient means, such as surrounding compression spring. 26. The inner fastener gripping surfaces of fingers 25 may be smooth or serrated, whicheveris'desired; The fastener has a forwardly projecting;

piercing portion 21a for penetrating the workpiece after being driven through the barrel while the piston has an.

abutment means or shoulder 24b to be described in further detail hereinafter. It should alsobe apparent that fingers 25 may be constructed in one-piece collet form with the extreme upper ends of all the fingers in Fig. 3 being integrally connected together by stopping each slot 25a short of its upper. end inFig. 3.

The safety features of the present invention are not required under normal conditions when there is no danger of' having the fastener escape into free flight. During tool loading, the fastener 21 is easily inserted through the barrel muzzle into the front of piston 22 so as to formv the driveable unit 26 and then this. unit is pushed, by any suitable means such as'a ram rod inserted into the tool muzzle, toward the breech of the tool barrel 15 until the Fig. 1 or position is reached. Then, an explosive charge, shown as cartridge 17, is inserted into the breech, the breech of the tool is closed, and the tool is moved to firing position in Fig. 1 against the workpiece 11. After trigger 16 is pulled, the fastener 21 is driven into the workpiece to its normal penetration slightly less than that shown in Fig. 3 with the rear of.

fastener 21 backstopped by the front of stem 23b to provide longitudinal rigidity to driveable unit 20 from head 2'3a to point 21a- If necessary, the driveable unit may be held in the barrel bore and the fastener may be held in piston 22 in any suitable mannerbefore the tool is fired so as to control the size of the initial explosive charge chamber, to prevent downward escape of. fastener 21 from the Fig. 1 position, and to properly drive the fastener. This may take the form of a frictional fit between the parts, or a suitable retaining device.

' However,.if the tool is fired so that there is a possibility of having the fastener escape into free flight to become a dangerous missile, the safety feature prevents this normal occurrence by engagement between suitable abutment means when the driveable unit attempts to travel outwardly through the barrel to or substantially beyond the Fig. 3 position. T001 barrel 15 has a uniform bore diamenter throughout most. of its length of a size to permit free passage of the unit 20 therethrough with no excess clearance or slop. However, this diameter is abruptly reduced in the present disclosure at the muzzle to form an integral flange 1521 of dimensions sufiicient to arrest the forward travel of the piston or ram 22 while permitting free passage of the piercing portion 21a of the fastener for workpiece penetration. forms an abutment means on the muzzle capable of coacting with the abutment means 24b on the. piston or ram to stop further axial forward travel of the driveable unit through the barrel and thus to prevent the free escape of the driveable unit from the tool. Fingers 25, however, continue their forward movement under their inertia when piston 22 is suddenly stopped, and these.

all. components come to rest, release spring 26 moves.

fingers 25 rearwardly tothe substantially released position shown in Fig. 2 which: permits axial withdrawal of the.

tool from the driven fastener. Hence, the driveable Hence, this flangev unit is stopped as its piercing portion 21a emerges a predetermined distance beyond the barrel muzzle so as to control the penetration of the workpiece or travel beyond the muzzle independently of the resistance to penetration of the workpiece material or of the explosive driving force.

This construction provides greater safety in tool operation as well as. more satisfactory setting of' the fasteners. It prevents the free escape of a fastener. The tool operator cannot dangerously fire the fastener into freeflight, as a dangerous missile, by firing the tool into the; air 'instead' of against the workpiece. If the workpiece does not have sufficient resistance to penetration, there exists neither the danger that the fastener will emerge from the other side of the workpiece as a missile in free flight nor the danger that the fastener will be overdriven eyond the depth control established by the engagement of the abutment means on the driveable unit and at. the barrel muzzle. Substantial inclination of the barrel bore from. the normal to the. workpiece surface will not cause a richochet' since the fastener cannot escape into free flight.

When the fastener is. driven either to the normal penetration position or is driven beyond this point until the abutment means engage in the Fig. 3'position, the fastener 21 can be easily removed from the tool while remaining embedded inthe workpiece. When forward movement of driveable unit 20 stops, spring 26 pushes the fingers 25 rearwardly to their normal released position. Then, the fastener 21 is easily disengaged from the tool and the fastener carrier piston or captive ram 22 by withdrawing the tool axially off driven fastener 21. so that the latter now assumes the Fig. 4 position.

Gas ports 15d in Fig. 1 are preferably providedin the tool barrel to permit gas escape from behind head 23a before unit 20 reaches the Fig. 3 position so as not only to reduce the likelihood of high and dangerouspressures developing in the tool barrel but also to minimize tool lift off the workpiece caused by the expanding pressure of the gas in the barrel bore tending to move the tool if the unit 20 stops before the Fig.3 position is reached;

Although the. fastener gripping means is disclosed as being on the fastener carrier piston member for arresting the forward travel. of fastener 21 in Fig. 3', some of the advantages herein are obtainable by similar gripping means provided at the muzzle on barrel member 15 after alteration in structure. Then, the fastener itself could havev a piston portion thereon instead of requiring. a separate fastener carrier.

Various changes in details and arrangement of parts. can be made by one skilled in the art without departing from either the spirit of this invention or the scope of the appended claims..

What we claim is:

1. A power actuated tool, comprising means providing, a passageway having. a discharge end so that an explosive powder charge can drive a driveable unit therethrough,

said driveable. unit comprising a driving piston adapted to move forwardly along said passageway a fastener. having a head part and a forwardly projecting piercing portion for penetrating a. workpiece, means on said driving piston disposed in a fastener released position while saidpiston is moving through said passageway, stop means. disposed at the discharge end of said passageway andi'n position to engage with and intercept the forward mo.vement of said driving piston, said means on said driving. piston being responsive to said stop means engaging. and intercepting said driving piston to move into a fastener gripping position at the discharge end of said passageway to. step forward movement of. said fastener through; the passageway with the piercing portion-thereof adapted to travel a predetermined distance beyond the discharge.

end for workpiece penetration. and to permit axial with,

drawal of said tool off a driven-fastener with thepiercing portion of said fastener adapted to remain driven in the workpiece, said driveable unit and said fastener being detachably connected against separating movement at the instantwhen said stopping action occurs.

2, In combination, a power actuated tool and a driveable unit adapted to be driven thereby, said tool including means providing a passageway so that an explosive powder charge can drive said driveable unit through said passageway toward the discharge end thereof, said driveable unit comprising a fastener carrier adapted to carry along said passageway a fastener with a forwardly project ing piercing portion for penetrating a workpiece when driven by said tool, stop means disposed at the discharge end of said passageway and in position to engage with and stop the forward movement of said driveable unit, means on said driveable unit being responsive to said stop meansengaging and stopping said driveable unit to move into gripping position with said fastener at the discharge end of said passageway with the piercing portion of said fastener protruding a predetermined distance beyond the discharge end for workpiece penetration, said means on said driveable unit being in a fastener released position during driving of said carrier, said last named means being movable to said gripping position with said fastener the instant stopping of said driveable unit occurs and thereafter 'movable relative to said fastener to permit axial withdrawal of said tool off said fastener with the latter driven in the workpiece.

3. In combination, a power actuated tool and a driveable unit adapted to be driven thereby, said tool including a member providing a passageway so that an explosive powder charge can drive the driveable unit through said passageway toward the discharge end thereof, said drive able unit comprising a carrier member adapted to carry along said passageway a fastener with a forwardly projecting piercing portion for penetrating a workpiece when driven by said tool, means located at the discharge end of said passageway to stop forward movement of said carrier member along the passageway with the piercing portion adapted to travel a predetermined distance beyond the discharge end for workpiece penetration and to permit axial withdrawal of said tool off a driven fastener with the fastener adapted to remain driven in the workpiece, and fastener gripping means on one of said members for detachably securing a fastener to one of said members by moving to fastener gripping position in response to stopping of said carrier member.

4. A power actuated tool including means providing a passageway so that an explosive powder charge can drive a driveable unit through said passageway toward the discharge end thereof, said tool adapted to drive along said passageway a driveable unit including a driving head adapted to carry along said passageway a forwardly projecting piercing portion of a fastener for penetrating a workpiece, and fastener gripping means movable to fastener gripping position for stopping forward movement of said piercing portion in response to said piercing portion traveling a predetermined distance beyond the discharge end for workpiece penetration and means for then releasing said gripping means for permitting axial withdrawal of said tool off a driven fastener with the fastener adapted to remain driven in the workpiece.

5. In combination, a power actuated tool and a driveable unit adapted to be driven thereby, said tool including means providing a passageway so that an explosive powder charge can drive the driveable unit through said passageway toward the discharge end thereof, said driveable unit comprising a fastener carrier adapted to carry along said passageway a fastener with a forwardly projecting piercing portion for penetrating a workpiece when driven by said tool, means located at the discharge end of said passageway to stop forward movement of said carrier along the passageway with the piercing portion adapted to travel a predetermined distance beyond the discharge end for workpiece penetration and to permit axial withdrawal of said tooloif a driven fastener with the fastener adapted to remain driven in the workpiece, and inertia operated fastener gripping means on said carrier for detachably securing a fastener thereto by moving to fastener gripping position in response to stopping of said carrier.

6. In combination, a power actuated tool and a drive able unit adapted to be driven thereby, said tool including a member providing a passageway so that an explosive powder charge can drive the driveable unit through said passageway toward the discharge end thereof, said driveable unit comprising a carrier member adapted to carry along said passageway a fastener with a forwardly projecting piercing portion for penetrating a workpiece when driven by said tool, means located at the discharge end of said passageway to stop forward movement of said carrier member along the passageway with the piercing portion adapted to travel a predetermined distance beyond the discharge end for workpiece penetration and to permit axial withdrawal of said tool off a driven fastener with the fastener adapted to remain driven in the workpiece, and normally substantially released fastener gripping means on one of said members'for' detachably securing a fastener to one of said members by moving to fastener gripping position when said carrier member is being brought to a stop.

7. In combination, a power actuated tool and a driveable unit adapted to be driven thereby, said tool including means providing a passageway so that an explosive powder charge can drive the driveable unit through said passagewaytoward the discharge end thereof saiddriveable unit comprisinga fastener-"carrier adapted to carryalong said passageway a fastener with a forwardly projecting piercing portion for penetrating a workpiece when driven by said tool, means located at the discharge end of said passageway to stop forward movement of said carrier along the passageway with the piercing portion adapted to travel a predetermined distance beyond the discharge end for workpiece penetration and to permit axial withdrawal of said tool 013? a driven fastener with the fastener adapted to remain driven in the workpiece, and normally substantially released and inertia operated fastener gripping means on said carrier for detachably securing a fastener thereto by moving to fastener gripping position in response to stopping of said carrier, said gripping means including wedge-shaped fingers mounted for movement by inertia to fastener gripping position during stopping of said carrier and including resilient ;means normally biasing said fingers to substantially released position.

8. A power actuated tool including a member providing a passageway so that an explosive powder charge can drive a driveable unit through said passageway toward the discharge end thereof, said tool adapted to drive along said passageway a driveable unit including a driving head member adapted to carry :along said passageway a forwardly projecting piercing portion of a fastener for penetrating a workpiece, means located at the discharge end of said passageway to stop forward movement of said head member along the passageway with the piercing portion adapted to travel a predetermined distance beyond the discharge end for workpiece penetration and to permit axial withdrawal of said tool 01f a driven fastener with the fastener adapted to remain driven in the workpiece, and normally substantially released fastener gripping means on one of said members for detachably gripping a fastener thereby by moving to fastener gripping position in response to stopping said head member, said means including on said one member an outwardly and rearwardly tapered bore and wedge-shaped fingers mounted in said bore for movement relative to said bore to fastener gripping position against the taper of said bore during stopping of said fastener and including resilient means normally biasing said fingers to substantially released position,

7 9-. A. power actuated tool including means providing a passageway so that an explosive powder chargecan drive a driveable unit through. said passageway toward the discharge end; thereof, said tool adaptedv to drive along said passageway a. driveableunit including a driving head adapted to carry along said passageway a forwardlyprojecting. piercing. portion of a fastener for penetrating a workpiece, and normally substantially released fastener gripping means on. said driving: head effective at the dis charge end of said passageway for detachably connecting afastener to said means by moving to fastener. gripping position inresponse to. stopping of forward movement of saidpiercing portion, said. gripping means including an outwardly and rearwardly tapered bore in said driving; head andwedge-shape fingers mounted in said bore for movement relative:- tosaidbore to fastener gripping position against the taper of said. bore: during. stopping of said: head and. resilient means normally biasing. said fingers toifastener releasedposition.

10.. A driveable unit. adapted to be driven through a passageway in a power actuated tool toward the discharge endthereof', comprising a fastener carrier adapted. to be a. captive within. said tool passageway and. to carry through said tool. passageway a fastener with a forwa-rdly projecting piercing portion for penetrating a workpiece when driven by said tool, said carrier includinga bodyhaving an outwardly and rearwardlytapered blind bore extending inwardly from its, forward end and wedge-shaped fingers mounted in said carrier bore for movement. by inertia to fastener gripping position against thetaper of said carrier bore during stopping of said carrier for detachably securing a fastener thereto.

11. A. dri-Veable: unitz adaptedto be driven through a passageway in. a power actuated tool} toward. the discharge end thereon. comprising: a fastener carrier adapted. to: be a captive within said tool. passageway and to carry through said tool passagewaya: fastener with a. forwardly projecting piercing portion for penetrating; aworkpiece when driven by saidtool, said: carrier including; a body. including. fingers mounted for movement relative to said body by inertia to; fastener gripping position during stopping of said carrier for detachably securinga fastener thereto, and including resilient means normally biasing said fingers to released position.

12. A driveable unit adapted to be: driven through a passageway in apower actuated tool. towardthe dischargev end thereof, comprising a fastener carrier adapted. to be a captive within said tool passageway and. to carry through said tool passageway a fastener with a forwardly projecting piercing portion forpenetrating; a. workpiece when driven by said tool, said carrier including. a body having an; outwardly and rearwardly tapered blind bore extending inwardly from its. forward end, including wedge-shaped fingers. mounted in said carrier bore for movement by inertia to fastener grippingposition against the taper of said carrier bore during stopping of said carrier for detachablysecuring; a fastener thereto, and including; resilient means: normally" biasing. said fingers: to released position.

Norway Aug. 23 1954 Great Britain Feb. 15, 1956'-

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