US2540106A

US2540106A - Nailing machine

Info

Publication number: US2540106A
Application number: US674008A
Authority: US
Inventors: James K Eichelberger
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-06-03
Filing date: 1946-06-03
Publication date: 1951-02-06
Anticipated expiration: 1968-02-06

Description

pfih 1953 J. K. EICHELBERGER M NAILING MACHINE Filed June 3, 1946 6 Sheets-Sheet 1 FIG.

2 Q 16 Q 16 Q INVENTOR. H6. 1 J. K. EICHELBERGER ATTORNEY Feb. 6, 1951 J. K. ElCHELBERG ER NAILING MACHINE 6 Sheets-Sheet 2 Filed June 5, 1946 INVEN TOR. J K. EICHELBERGER ATTORNEY Feb. 6, 1951 J. K. EICHELBERGER NAILING MACHINE Filed June 5, 1946 6 SheetsSheet 3 FIG. 13

INVENTOR. J. K. EICHELBERGER ATTORNEY Feb. 6, 1951 J. K. EICHELBERGER NAILING MACHINE Filed June 5, 1946 6 Sheets-Sheet 4 INVENTOR. J. K. EICHELBERGER ATTDRNEY Feb. 6, 1951 J. K. EICHELBERGER NAILING MACHINE 6 Sheets-Sheet 5 Filed June 3, 1946 R E m R E mm Hum .9 mm 2 D E 4 K k a J cl I FIG. 10

ATTORNEY Feb. 6, 1951 J. K. ElCHELBERGER NAILING MACHINE 6 Sheets-Sheet 6 Filed Jun 3, 1946 I ii: I: ii ElEIEIEIEIEIEE R a R 0 E m T B N NL 5R m mm \M E v Patented Feb. 6, 1951 UNITED STATES PATENT OFFICE Application June 3, 1946, Serial No. 674,008

12 Claims.

This invention relates to an improved method and to improved apparatus for constructing building elements such as prefabricated wall sections or panels, and particularly to an improved method and improved apparatus for securing together the various components of such sections.

A great deal of attention is being directed at present to the provision of prefabricated buildings particularly for homes and the smaller industrial and storage buildings. The building of small and medium size prefabricated homes is of major importance in view of the current national housing shortage as such homes can be assembled on location in a very short time by a small amount of skilled labor and at a cost substantially below the cost of conventional, on location construction.

In order to maintain the costs at a minimum and obtain maximum production, methods are being devised for using standardized materials for all the necessary sections and for manufacturing the sections and assembling them into completed buildings with a minimum amount of hand labor.

In my previous application Serial Number 648,149, filed February 16, 1946, now Patent Number 2,487,019, for Panel Fabrication I have disclosed an improved method and improved apparatus for securing the side or cover components to frames to provide complete building sections. The present invention deals particularly with the construction of the frames although it may be used to advantage for other purposes such, for example, as securing the side covers to the frames in those cases where it is desired to nail the covers in place.

It is therefore an object of the present invention to provide an improved method and improved apparatus for assembling and securing together the members constituting the frames of prefabricated building wall panels.

A further object resides in the provision of improved frame assembling apparatus including an assembly jig for the frame members and power operated nailing means for securing the frame members together in assembled relationship.

A still further object resides in the provision of an improved automatic nailing machine arranged to simultaneously drive nails at a plurality of different locations and having features of adjustment whereby it may be adapted to changes in the position of the nailing locations.

Further objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a side elevational view of an assembly apparatus illustrative of the invention;

Fig. 2 is a bottom plan view of the upper member of the apparatus illustrated in Fig. 1;

Fig. 3, an elevational view of a nail driving unit constituting a component of the assembly unit shown in Fig. 1;

Fig. 4, a longitudinal sectional view of the nailing unit shown in Fig. 3, taken on the line E--4 of Fig. 3;

Fig. 5, a detailed view of a fragmentary portion of the apparatus showing the manner of attaching the nailing units to the member on which these units are supported;

Fig. 6, a perspective view of a stack of mutually attached nails as used in the nail feeding magazine of the apparatus;

Fig. '7, a sectional view of the nail feeding magazine showing a stack of attached nails in place therein;

Fig. 8, a view similar to Fig. 7, showing the magazine after a portion of the nails in a stack have been used;

Fig. 9, a top plan View of a modified form of nailing apparatus;

Fig. 10, a view partly in section substantially on the line l0lll of Fig. 9;

Fig. 11, a perspective view of one form of positioning element used to hold structural elements in proper position during assembly;

Fig. 12, a perspective view of a guide element for the nailing apparatus;

Fig. 13, a side elevational view of a further modified form of assembling apparatus;

Fig. 14, an elevational view of a modified form of hydraulic nail driving unit;

Fig. 15, a longitudinal sectional view of the modified unit shown in Fig. 14; and

Fig. 16, a transverse sectional view on the line l6i6 of Fig. 15.

With continued reference to the drawings and particularly to Figs. 1 and 2, the assembly apparatus comprises a movable table or platform,

a generally indicated at I5, supported on wheels or rollers it. This table may conveniently comprise a top frame I! of grid form firmly secured to the under surface of a flat plate is having an area greater than the platform area of a structural frame [9 the elements of which are arranged on the upper surface of the plate l8 for assembly into a completed frame or similar device. The grid frame ll may be supported on a plurality of vertical columns, three of which are shown in Fig. 1 and indicated at, 29, 21, and

determined position relative to a suspended nailing apparatus, generally indicated at 25.

The nailing apparatus comprises a flat plate 25, preferably of steel or other hard metal, to the upper surface of which is secured a reinforcing grid frame 2? composed of structural iron members, such as channel irons or I-beams arranged in two sets of parallel members as indicated at 28 and 29 in Fig 2, the members of the two sets being disposed at right angles to,

each other. The nailing mechanism is suspended by suitable means, such as the ring 35 from an electric or mechanical hoist by a suitablechain or cable 3i The members 32 of a sling or bridle are connected to the ring and have their ends connected at spaced apart points to the frame 21' by suitable means such as the rings or eyes3 3.

A plurality of nail driving units, generally indicated at 34, and illustrated in detail in Figs, 31

illustrated in Fig. 9 wherein the positioning elee ments are shown in position at the corners where the elements of the frame come together. The

outer frame corners are supportedby suitable.

angular members 31.

When it is desired to secure the elements of a frame together, the table 55 with frame elements in position for assembly thereon is moved into proper position under the nailing device 25 and the device 25 is then lowered into operative position over the frame elements. This will bring.

the various nail driving units 36 into operative position opposite the nailing locations of the frame. and the depending guide. members 35 in position to. hold the nail driving units in proper operative position and also counteract at least in part the nail driving force applied to the frame elements.

As shown in Fig. 2, there are a number of nail driving units secured to the plate. 26, one unit being disposed opposite each frame. joint into which nails are to be driven.

The positions of the elements of the illustrated frame are indicated by phantom lines in Fig. 2. The frame indicated is the frame of a comparatively large building wall panel having a doorway therein. The inner group of six nailing members is positioned within the doorway opening tosecure the side members defining the doorway to transverse frame members, the intermediate. group of two nail driving units is positioned to drive the nails securing the door lintel in place and the outer group of 14 nail driving units is positioned to secure the outer frame elements together and to the ends of the internal elements.

A pressure fluid line 35 is connected by suitable conduit means, including a main conduit Ml and individual branch conduits, with the various nail driving units. The line 39 leads from a control valve 4| which is connected by suitable conduits 42 and 43 with a source of fluid under pressure and with a fluid sump or reservoir, the valve being operative to connect the nail driving units with fluid under pressure or with exhaust as may be required to carry out the nail driving operation. The nailing units may be secured to the plate 26 in various operative positions, as will be. later described in detail, in order to accommodate thenailing mechanism to panels or panel frames of varying size and shape.

Referring now to Figs. 3 and 4, each nailing unit 34 has a cylinder 44 connected at one end to a support, generally indicated at 45, and closed at its opposite end by a suitable end closure cap 46. The cap 46 may be provided with an internallyscrew threaded flange screwed upon the externally screw threaded end portion of the cylinder and suitable packing 41 may be provided between. the endof the cylinder and the cap to prevent leakage of hydraulic fluid past the cylinder end closure. The capis provided with an aperture into which is threaded a suitable fitting 4.8. to whichv the associated branch conduit is connected. The end of the cylinder secured to the support is closed by a closure plate 49 having a central apertured boss 50 through which a rod 5| is slidable. This rod extends into the cylinder substantially coaxial therewith and its movement into the cylinder is limited by a stop shoulder 52. secured on the end of the rod in position to abut the end of boss 50 at the limiting position of the rod. A piston, generally indicated at 53, is secured on the opposite end of rod 51 between ashoulder 54 on the rod and a nut 55 threaded onto the reduced screw threaded end portion of the rod. This piston comprises a rigid metal plate 56 resting against the shoulder 54', a plate 51 superimposed on plate 56, a packing or washer 58 of resilient material, and a washer 59. compressing the resilient. material between itself and plate 58. A pair of nail driving rods or punches 60 and iii are disposed within the cylinder parallel to rod 5| and have enlarged end portions received in countersunk apertures in plate 56 and held therein by plate 51' so that the punches are securely connected to the piston against movement in either direction relative thereto.

The punch members 60 and 6-1 extend through respective apertures in closure end plate 49 and through. hollow socket members 62 and 63 secured to the closure end plate.

The; support member 45: comprises an end plate 64 welded or otherwise suitably secured to the cylinderat the end thereof, a second end plate 6.5 spaced from the plate 64 and substantially parallel thereto, an upper side plate 66 and a lower side plate 61 secured at their ends to the spaced

end plates

64 and 65. The end plate is providedwith apertures 58. and 69 in line with the axes ,of the nail punch members 60 and Si and each of these apertures 68 and 69 is squared and in its side adjacent the end plate 54, plate 65 is, provided with circular counterbores which are substantially coaxial with the apertures. When the. punch members Eiland 6! are fully extended their ends opposite the piston 53 extend through the apertures 68 and 69 respectively substantially to the plane. of the outer surface of the plate 65. The. plate 65 is provided with a tapered guide portion 70 extending beyond the side plate 6'! and at the inner side of the side plate 66 is provided with an elongated rectangular aperture through which the-tongue portion H of a guide member'lZ may be-inserted, the guide member being secured to the support by suitable means, such as the screws 73, extending through the side members 66 and threaded into the tongue H of the guide member. The guide member 12 is used for side elements and is removable when it desired to use the nail driving units on a flat surface where the guide or stop member 12 would interfere with I the proper operation thereof.

Two headed lug or button members 14 and 15..

are secured to the side plate 45 adjacent the

end plates

64 and 65 respectively. Each of these members comprises, as indicated for the member M, a reduced screw threaded shank l6 screw threaded into a threaded aperture in the side member 45, an intermediate cylindrical portion ill, the lower end of which abuts on the side member surrounding the aperture, and an enlarged cylindrical head portion 18 which provides an annular shoulder at the adjoining end of the intermediate cylindrical portion 11. The operation of this fastening means is particularly illustrated in Fig. 5.

The plate 26 is provided with a plurality of apertures each of which has a key hole shape. That is, the aperture is elongated and at one end is of circular shape of a diameter sufficient to permit the passage therethrough of the head portion 18 of the lug member. Joining this circular portion of the aperture there is a smaller, partly circular, portion which fits about the intermediate cylindrical portion 11 of the lug member. When the lug member is passed through the larger portion of the aperture and then moved relative to the plate 26 to bring its intermediate cylindrical portion into the reduced portion of the aperture, the shoulder between the head portion and the intermediate cylindrical portion will overlie the plate around the smaller part of the aperture and the member will be securely hooked in place.

The apertures are so arranged that the movement of the headed members relative to the plate to secure the nail driving unit to the plate is in the same direction as the reaction to the nail driving force exerted by the nail driving unit. The plate apertures are arranged in pairs, as indicated at '39 and 80 in Fig. 2, to receive the two spaced headed lug members of each nail driving unit. Pairs of apertures are provided at various locations on the plate, as indicated at 19a, and 7%, so that the nailing units may be moved to various positions to accommodate the mechanism to the assembly of frames or panels of different size and shape.

In operation the apparatus would be set up for a particular size and shape of panel, one or more jigs being permanently arranged for this particular panel. After a suitable number of particular panel frames had been manufactured, a different jig could be substituted providing a panel of different shape or size or both and the nail driving units could then be moved to new positions for the assembly ofthe new frame or panel. By this'arrangement frames or panels of several different sizes and/or shapes can be manufactured using the same assembling apparatus.

A special nail particularly adapted for use, in the operation and means for supplying the nails to the nail driving mechanism are particularly shown in Figs. 6, '7, and 8.

Referring to Fig. 6, a T-shaped nail having an elongated head of a width substantially the'same as the diameter of the nail shank has been found particularly suitable for use with the automatic nailing device. stacks as indicated at 82 which may include any These nails are provided in i desired number of individual nails 83, .I4 being .nail feeding means and may be easily broken away from the stack when they are driven by the nail driving means.

The nail feeding magazine, as particularly illustrated in Fig. 7, comprises a hollow metallic casing es, the internal opening of which has a size and shape corresponding to the planform size and shape of a nail to be used in the device, the opening being particularly shown at in Fig. l. At the bottom of the casing the opening is widened, as indicated at 85' in Fig. 4, to a width throughout its length at least as great as the major dimension of the nail head so that the heads of the nails may pass longitudinally through the lower part of the magazine casing. At one side of its bottom portion, the magazine is provided with a lateral cylindrical extension 86 and at its opposite side with a shorter cylindrical extension 87 at the outer end of which there is provided a non-circular, preferably square, extension 33. The extension 86 is of a size to fit into the tubular receptacles 62 and 63 mounted on the nailing unit in. axial alignment with the nail driving punch members 6!] and BI.

The magazine casing is mounted on the nailing unit by inserting the end of the cylindrical extension 86 of a magazine casing in one of the hollow receptacles 52 or '53 and moving the casing bodily to the left, as viewed in Fig. 4, to compress the corresponding receptacle included spring 89 and .iii until the end of the extension 88 will pass the inner side of the outer end plate 85 of the support 65. The extension 88 is then brought into alignment with the corresponding aperture $8 or 69 and the pressure is relieved permitting the receptacle spring to move the cas- .ing toward the right, as viewed in Fig. 4, to move the non-circular extension 88 into the corresponding non-circular aperture in end plate 65. When this is done the cylindrical extension 81 will enter the cylindrical counterbore surrounding the aperture at the inner side of plate 65 and abut against the shoulder between the aperture and the counter-bore. The magazine casing will then be releasably locked in operative position in which it extends substantially perpendicular to a plane including the axes of the two nail punch members 6!! and ti and will be held against rotation in the nailing unit.

The magazines may be removed and replaced by a simple operation first compressing the corresponding spring 89 or 9.5 and then moving the magazine out of the support t5 and, in replacing, by first compressing the corresponding receptacle spring and then moving the magazine until the extension 88 snaps into aperture in plate 65 in the manner indicated above.

In order to load the magazine, a stack 82 of mutually adhering nails is inserted into the open end of casing 84 and moved inwardly until the nail at the corresponding end of the stack is positioned at the bottom of the opening in the casing. A cap or closure member 92 is then placed upon the outer end of the casing. This closure member has a flat accordion type spring 93 secured to the inner surface thereof which spring is receivable in the opening in the case 85 and bears upon the outer end of the nail stack. The closure member is releasably locked in place by suitable means, such as the finger actuated slidemembers 94 and 95, which pass throughiapertured blocks-I 9fii and slzomthe outer: surface of the; member 92 and: project at: their outer ends: through, apertures; provided: in the; lugsclor1ears-f98 and -99-secured-to theside of then casing and gextending. outwardly therefrom; The: members 9.4 and- 95 aresurged apart: by suitable means such as the compression spring; I:

With this arrangement the cap may; be; rejmoyed-by compressing the outwardly turnedain ner ends of; the members 9.4 andp95; against. the;

force; of spring: I00 untilthe outer ends- 0f theseg members-are withdrawn; from the ears 98i and:

99-1 and maybe secured to the casingby-simply' forcing. itin-wardly until the outerends of*the* members-94 and 9.5-snap'into the openings in thecare; the spring I00 being finger compressedqif necessary-at:.the.-beginning, ofthe operation. As.

the-nails-are-removed from the-stack in themaga azine. thespring 93. expands, as illustrated in.

Fig. 8; to move the nail stackinwardlyand main,-

tain the-bottom nail of the: stack at the bottom;

ofi the 'cpening, in; the case 84 whereitwill. be contacted by'the adjacent end of thecorresponding nail-1 punch 6Ilor 6 I-.

Whenloadedmagazines are applied to thenai1ing-= unit and fluid under pressure is admitted throughgthei fittingw; the piston-53 will beforced lengthwise of the: cylinder 44 to theright, as

viewed iniFig, 4:, forcing the nailpunch members 60-and 6-I'-through-themagazines 84 and184 thereby-Uforcing. the two nails-at: the bottoms of the two;magazinesslengthwise of the magazines and through the magazine extensions 81 and 88 re-- ceived inthe-counter-bore 68. and aperture 69 in. therendplate 65 until-the-nail heads .arewmoved. to. a.v position flush with. the: surface of aframe memberincontact with the other surface. of end plate 6.5-.

Arrv adjustable limit stop, I QI: isprovidedf in the end: plate- 65; tocontact thecorresponding. end of guide rod.- 5.I-. to positively control the amount by: which the nail. heads are. sunk. into the wood of. the frame member.

In Figs 9 and. 10 is illustrated a somewhat modified-.foi'mofnailing apparatus in which. the.

supporting plate I04 for. thenail. driving units constitutes. the top of the table 01'. platform supporting the frame members thereby assembled and to: which thepositioning. members forming: theassembly. jigare attached. The under sur.-. face. of plate I04 issecuredlto. a supporting andreinforcing grid: frame I115. carried. on suitable columns or legs, as indicated. at I06. and I01 in; Fig. 10. Corner guide members. 36 are secured to the upper surface of the plate IMby suit: able bolts or rivets. passing through apertures. in. the plate either singly or in groups. of two. or. four at the corners. where. the elements. of the frame come together and sidepositioning. mem.-. bars are secured. to the plate singly. at-locations. selected to hold the longer elementsof the frame in proper position. for assembly.

As particularly shown. in: Fig. 11,, each. corner. positioning member comprises a flat. base por-. tion I03 which: may be of. generally hexagonal. ."ha-pe and one end of. which. is; integralwith an upstanding guideportion I09 having two flat. leg portions disposed at. right anglesto each other. The portion N19 has its: outer surfaces beveled at its upper end asindicated at |.I\llto facilitate. the placing. of. the frame elements. inthe jig.

While the plate: could beprovided; with groups; of: apertures; so that the positioning. members could b'e moved tovary the jig; in; accordance with difi'erenceai in; the shape and .size'; of. the

frames; tozbe: assemb1ed,..it.is at. present] believed economically-a desirable to;. provide separate: jigs for-: the different types of:- panel: frames.,

The plate: I104. has; an area. greater than the planform area of thefram'e to be assembledrby tures forfdiifferent; positioningnfi the nailing units;

ifronly one s type-: of frame: is assembled with this. partizmlar'- arrangement; The. frame shown". in Figs. 9 and 10 is smaller and somewhat different inr shape: from. that indicated in Figs. I and 2 andgisxind-icatedeby theiznumeral I'9.

When: the nailing. units; are. attached directly to the jig. platformror' plate as. inFEigs. 9 and 10,. theldept'h controlling. stop member. 12: is removed as. the: jig; plate: then performs. the: functions performedaby: this stop; member in the suspended: nailing: unit shown: imFigs. 1i and 2;

hydraulic pumpaand reservoir I Ifs are. pro.- vided atrsome. location convenient tozthe: assembly: and connected by; suitable. conduits H6 and II-.'I"- with a threeew-ay." valve ILL-8' to. which the:

various. nail driving units: are; connected. by a suitable: maintccnduit: i I'9' and branch conduits With. this; arrangement. when. the frame elementsihavetbeene properly: positioned intheaframe jig the valve is operated to apply fluid pressure.

simultaneously; to all of: the nail driving units, whereuponall of: the joints of the frame are simultaneously nailed together. When the nails have; been completely driven the valve is operated to,;connect thecyl-inders of: the nail driving-units with. the; fluid exhaust line whereupon the several return springs retract the nail driving punclr members-- and the completed frame may. therrberemoved from the jig and a new frame as'sembled therein.

I;ng'the-.modifiedr arrangement shown in Fig. 13, aplatform: I24-i is supportedon' vertical columns or" legs" as indicated: at; I25 and IE6 with the columns at two opposite sides of the platform extending; abovextherplatform. Suitable positioning members, as: indicated at I Z'I- and I28, are secured on the upper surface of the platform to hold.a panel framesuch as the frame I9 and a panel: cover member; I291 in proper position for assembly.- A transverse member I30 extends between. two corresponding upright leg orcolumn members, positioned one'at each side of the platform, and to this transverse member a plurality ot'spacedna-if driving units 34 are connected in the manner" indicated above by the engagement of headed 'lug' members on the'nail driving units in key hole shaped apertures as indicated at I3I, provided in the transverse member. Suitable mean a indicated at I32 and I33 are provided to'adjust'ably and releasably connect the ends of the transverse members to the corresponding upri'glitmembers sucrrastheimembers I25 and I26. These means. may; each comprise a hydraulic expansible. chamber device. I34 as indicated for the unit I32 the-cylinder of. which rests on platform Iuand; the; piston: of: which-isv connected to a 9 latch member I35 pivoted to the transverse member I30. i

The latch member I 35 has a depending hook portion engageable with a projection I36 on member I 25 and is urged into locking engagement with the projection by spring I31. Application of fiuid pressure to the units is controlled by valve I38 and when pressure is applied the piston of each expansible chamber device is raised turning the associated latch member, such as I35, to release extension I36. When the latch member has been turned sufliciently to free it from the extension or dog I36 it comes against a stop its after which further extension of the piston raises the corresponding end of member venient to the nailing apparatus and is connected by fluid lines M2 and I43 with a three-way valve M4 which is in turn connected by a main conduit I45 and branch conduit I46 with the several nail driving units. It is to be understood that a plurality of transverse members sim lar to I30 may be used extending between corresponding upright members at opposite sides of the platform and that each transverse member may carry the necessary number of nail driving units properly spaced to position them opposite the desired nailing locations. With this arrangement, when the valve Mt is operated to apply fluid pressure to the several nail driving units all of the panel cover nails will be simultaneously driven.

In the modified nailing unit shown in Figs. 14, 15 and 16, the operating principle and general construction is the same as that illustrated in Figs. 3 and 4 and described above. In the modified arrangement, however. a different spring arrangement is provided and different end plates are used to cooperate with th modified spring arrangement.

In the modified arrangement the end plate 64' of the support 45 is made cross-shaped in order to provide radially extending arms IMia, I817, I630 and I-'i8d apertured to receive the ends of corresponding tie rods I IQa, M92), I 490, and Iild and to provide space between adjacent arms for the external tension springs I59 and I5 and is provided with an annular groove for the reception of the corresponding end of the cylinder 44. The outer end. closure member I52 may be circular in shape, has a diameter larger than the cylinder diameter in order to provide an angular overchange to which the tie rods and springs may be connected, and is also provided with a cylinder receiving annular groove.

As is particularly shown in Figs. and 16, the four tie rods are substantially equally spaced around the cylinder and are passed through apertures in end plate 65' until their enlarged or upset end portions engage the plate. At their opposite ends the tie rods pass through corresponding apertures in end plate I52 and have screw threaded end portions upon which are threaded nuts as indicated at I53 which are tightened on the tie rods to compress the cylinder between the end plate 6 5' and the outer end closure plate I52. The coiled tension spring I50 and I5I are 10- cated. at substantially diametrically opposite positions externally of the cylinder 44 and are connected at their outer ends to the plate I52 by having hook portions extending through suitable apertures in the plate. At their inner ends these springs are connected to the corresponding ends of a cross member I54 which is connected at its center to the end of guide rod M. The cross member I54 is made in a modified S shape to clear the magazine receptacles 62 and 63.

With this arrangement when hydraulic fluid under pressure is supplied to the cylinder through the fitting 48, the piston 53 and guide rod 5| are forced inwardly, moving the cross member I54 away from the end closure member I52 and thereby stretching the tension spring I50 and I5l. When thepressure is released these springs contract and return the piston and guide rod to the retracted position. The nail punches 60 and 6| are connected to the piston in the manner indicated above in connection with Figs. 3 and 4 and pass throu h the support 55 and through the nail ma azines M and 84' mounted in the support.

It has been found that in some ca es the tension sprin s have certain advantages over the compression spring arrangement shown in Fig. 4 in that a desired portion of the spring action may be selected and less s ace is required. and it is not necessary to brine the sprin s to a substantially solid condition when retracted in order to conserve space. Otherwise the construction and operation of the modified form of nail driving unit is substantially the same as that illustrated in Fi s. 3 and 4 and described above.

It will be obvious to those skilled in the art that various changes may be made in the invention without de arting from the spirit and scope thereof and therefore the invention is not limited by that which is shown in the drawing and described in the specification but only as indicated in the appended claims.

What i claimed is:

1. Nailing apparatus for securing to ether the nailable elements of a panel frame or similar structure comprising a plate. having an area greater than the planar area of the frame to be assembled: positionin members fixed to said plate and extending thereabove to hold frame elements in proper po ition during as embly; a supporting and reinforcing structure below said plate: a plurality of fluid pressure o erated nail driving units onsaid plate individually disposed opposite respective nai ing locations; means securing said units to said plates: and means supplyim f u d under pres ure to said units.

2. Nailing apparatus for securing together the nailable elements of structural panels or similar devices comprising a platform for supporting the panel; sup ort members extending above said platform disposed at each of two opposite sides thereof; a transverse member extending between two support members located one at each'side of said platform; means releasably securing the ends of said transverse member to said support members; fluid pressure operated nail driving units spaced along said transverse member opposite respective nailing locations; and means detachably securing said units to said transverse member.

3. Nailing apparatus for securing together the nailable elements of panel frames or similar structures comprising a flat plate having an area greater than the planar area of the frame to be assembled; a reinforcing grid permanently secured to one side of said plate; means operative to suspend-saidpla'te and grid'assembly and'move it between an operative and an inoperative position; aplurality of nail driving units on the under side of said plate individually disposed opposite respective nailing locations; and means securing said units in preselected positions to said plate.

41. Nailing apparatus for securing together the nailable elements of a panel frame or similar structure comprising, a plate having an area greater than the planar area of the frame to be assembled; a supporting and reinforcing structure for said plate: a plurality of fluid pressure operated nail driving units on said plate individually disposed opposite :respective nailing 'locations; means releasably securingsaid nail driving units 'to said plate; andmeans supplying 'fluid under pressure tosaid units.

5. Nailing apparatus for securing together the nailable elements of panel frames or similar structures comprising a flat metal plate having an area greater than the planar area of said frame; means supporting said plate in substantially horizontal posit on; 'a plurality of fluid pressure o erated 'nail driving units on said plate individually dis osed opposite res ective nailing locations of said frame; means releasably securing said units to said plate arranged for changing the locat ons of said units to accommodate said ap aratus totheassembl-y-o'f frames of different sizes orsha-pes; meanssupplying-fluid under pressure to said units; and manually o erable means controlling said fluid supply; said securing means comprising spaced headed lugs on each nail driving unit receivable in plate apertures shaped to permit passage of the lug heads therethrough and to hold the lugs in restricted portions thereof upon movement of said unit in the direct on of the reaction to the nail driving force exerted thereby.

6. Nailing apparatus for securing together the wooden elements of a panel frame or similar structure com rising a plate having an area greater than the planar area of said frame, means support ng said plate, a plurality of fluid pressure operated nail driving units on said p ate individually dis osed opposite respective nailing locations of sa d frame; means securing said units to said p ate; and means su plying fluid under pressure to saidunits comprising a pressurefluid pump and reservoir; a control valve; a conduit connecting said valve with said reservoir; and condu t means connecting said valve with said plural tv of nail driving units.

7. Nailing apparatus for securing together the nailable elements of panel frames or similar structures comprising a flat metal plate having an area greater than the planar area of said frame; means supporting said plate in substantially horizontal position; .a plurality of flu d pressure o erated nail driving units on said plate individually disposed opposite respective nailing locations of said frame; means releasably securing said units to said plate arranged for changing the locations of said units to accommodate said apparatus to the assembly of frames of different sizes or shape; means supplying fluid under pressure to said units; and manually operable means controlling said fluid supply.

8. Frame assembling and nailing apparatus comprising an assembly jig for frame elements; nailing means supported for movement toward and away from said jig; and means guiding said J'ig relative to said nailing means; said jig comprising a wheel supported table and a plurality of "12 fixed positioning members on the top surface of said table; said nailing means comprising a rigid -st-ructural-grid, a plate attached to said grid and provided with keyhole shaped apertures arranged in duplicate at different positions to render said nailing means adjustable for different shapes and size of frames to be assembled thereby; and a plurality of fluid pressure operated nailing units secured to said plate in predetermined locations by means of lugs on said units received in corresponding apertures in said plate.

9. Nailing apparatus for securing together the nailable elements of a panel frame or similar structure comprising a plate having an area greater than the planar area of said frame, means supporting said plate, a plurality of fluid pressure operated nail driving units on 'said plate individually disposed opposite respective nailing locations-0f said frame; means securing said units 'to said plate; and means supplying fluid under pressure to said units.

10. Apparatus for assembling wooden members into a structural frame comprising fixed positioning members operative to hold the frame members in position for assembly; a plate superimposed on thearea of said frame; fluid pres- 'sure operated nailing'units located on said plate at the nailinglocations of said frame; and means releasably securing said units to said plate.

11. Frame assembly and nailing apparatus comprising an assembly jig for frame elements; nailing means supported for movement toward and away from said jig; andmeans guiding said jig relative to said nailing means; said jig comprising a wheel supported table and a plurality of fixed positioning members on the top surface of said table and means to prevent transmission of nail driving impacts to said jig and said positioning members.

'12. Nailing apparatus for securing together the nailable elements of a panel frame or similar structure comprising a plate having an area greater than the planar 'area of the frame to be assembled, a supporting andreinforcing structure for said plate, a plurality of fluid pressure operated nail driving units individually disposed opposite respective nailing locations, quick releasable means releasably securing said nail driving units in position with relation to said plate and means supplying fluid under pressure to said Number Name Date 187,843 Goodhue Feb. 27, 1877 243,997 Toepfer July 5, 1831 262,305 Myers Aug. 8, 1882 338,930 Chase Mar. 30, 1886 408,765 Swift Aug. 13, 1839 7 706,805 .Dargeault Aug. 12, 1902 1,407,295 Parker Feb. 21, 1922 1,539,473 Ellwood May 26, 1925 1,613,473 Miller Jan. 4., 1027 1,618,367 Dick Feb. 22, 1927 1,939,632 Randall Dec. 12, 1933 1,955,467 Morgan Apr. 17, 1934 2,008,831 Kruse July 23, 1935 2,014,452 Riggs Sept. 17, 1935 2,273,268 Hunter Feb. '17, 1942 2,321,165 Stilwell June 8, 1943 2,378,948 Paxton June 26, 1945