US 2572012 A
Description (OCR text may contain errors)
Oct. 23, 1951v A. J. CURTIS SEMIAUTOMATIC ELECTRIC NAILER 4 Sheets-Sheet l Filed Jan. 26, 1949 INVENTOR.
Oct. 23, 1951 A. J. CURTIS SEMIAUTOMATIC ELECTRIC NAILER 4 Sheets-Sheet 2 Filed Jan. 26, 1949 Oct. 23, 1951 A. J. CUR-ns SEMIAUTOMATIC ELECTRIC NAILER 4 Sheets-Sheet 5 Filed Jan. 26,'1949 A. J. CURTIS SEMIAUTOMATIC ELECTRIC NAILER 4 Sheets-Sheet 4 Filed Jan. 26, 1949 ANN www A HUH \U v NN wm .v mhd 14mm .um .Bmw
Bf mfg/amy@ Patented Oct. 23, 1951 Arthur J'. Curtis, Walla Walla, Wash., assigner of one-half to David (i.l Robanske, Walla Walla,
Application January- 26, 1949, Serial No. 72,845
The present invention relates to a semi-automatic electric hammer and nail set, andv more particularly to a portable elecrically operated hammer in which thev nails or other' fastening elements are fed to the pathway of the hammer nail set.
The primary object of the invention is to provide a semi-automatic electric hammer having a magazine feed which is controlled by' a single actuaor manually operated to close a circuit'- through alternate sol'enoids for controlling the hammer movement.
l Another object is to provide a semi-automatic electric hammer' and nail setting device in which the nails or other fastening elements' are fed to the pathway of the hammer-by means of'a magazine fed manually actuated control cylinder to permit the nails or other fastening elements tobe moved into the pathway of the hammer or nail set individually.
Another object is' to provide a semi-automatic eleciric hammer and nail setting device which is capable of being operated manually with one hand, thus leaving the other hand free to hold various workpiecesin place during nailing;
Another object is' to provide a semi-automatic electric hammer and nail Setting device which can be manually controlled to feed a nail or other fastening means in the pathway of the nai-1 set and hammerV and simultaneously' operate the hammer to producev a single stroke or a series of repeated strokes without feeding: another nail or fastening element.
Another object is to provide a` semi-automatic electric hammer and nail set inl which the' hammer is magnetically controlled by a manual selectively control switch to enable an electro-magnet to be energized to deliver` th'epower strokeV by attracting the armature of the hammer, andD to then be retracted by manipulation of the selective control switch which energizes another'L sole# noid or electro-magnet to retract the hammer and nail set to its starting' position.
Another object isto provide a semi-automatic electric hammer and fastener feeding device having a hand grip which is provided with a control switch which is operated by' the user`V when grasping the pistol gripV to completev the circuit through the control solenoid and render the trig` ger operator swiic'hv or' selectiveV control operable.
Another object is to provide a semi-automatic electric hammer in which the: fastening elements are contained? in a magazine and fed to a com trolv cylinder intothe pathy of the hammer orf nail set by a step to step motion controlled' by' the 2 selective triggerv switch, thus enabling a nail or fastening element to be projected into the path of the nail set or hammer by manipulating the the trigger conrol switch through a full stroke movement.
Another obiect is to provide a semi-automatic Velectric hammer having a trigger operated control switch capable of being selectively operated to cause repeated power strokes to be imparted to the nail set without' feeding another fastening element, and to be selectively manipulated to feed a nail or other fastening element into the path of the nail set or hammer upon each stroke or power -movement of the hammer. n
Othery objects and advantages of the inveniion will become apparent during the course of the followingv description of the accompanying drawings, wherein:
Figure 1 is a, longitudinal cross sectional view of the semi-automatic electric hammer and nail set showing the arrangement of the electrically operated hammer contro1 solenoids, the manner in which the nails or other fastening elements are individually fed to the pathway' of the hammer and the manual control mechanism for the solenoids ofthe electric hammer motor and the individual feed mechanism, the armature and ham-V mer being shown in their retractedposition.
Figure 2 is a longitudinal cross sectional view of the semi-automatic electric hammer and nail set similar to Figure 1, but showing the solenoid armature and nail set at'the end of its power stroke with the nail or other fastening element driven home inl the workpiece.
Figure 3 is a vertical cross sectional view taken on line 3--'3V of Figure l and looking in the direction of the arrows, to illuslrat'e the control cylinder feed' and magazinev for supplying fasteningelements to the controlv cylinder.
Figure lv is a vertical cross sectional view taken on line d-ll of Figure 1 and looking in the direction'- of the arrows, tov illustrate the control linkage for the nail feed and the arrangement ofthe solenoid armature. n
Figure 5 is a rear elevational View showing the hand grip switch for' maintaining' the circuit closed from thev power source during operation of the-electric' hammer and nail'set.
Figurel 6- a fragmentary verticalcross sec*- ticnal ViewY similar to Figure 31, but greatly' en-l larged to illustrate various structural details of the fasteningv element feed cylinder and the* arcuate slot in the hammer barrel.
Figure 7' is a vertical fragmentary' cross sec*- tional` View taken on the irregular line 1- 11' and looking in the direction of the arrows to illustrate the fastener element feeding cylinder and the circumferentially spaced projections engageable by the control linkage to advance the cylinder a predetermined angular distance and thus project a nail into the hammer pathway.
Figure 8 is a fragmentary view of the trigger control switch showing the same greatly enlarged to illustrate the spring loaded contact for permitting repeated operation of the hammer without feeding a fastening element to the hammer pathway.
Figure 9 is a transverse cross sectional view taken on the oblique irregular line 9 9 of Figure 1 and looking in the direction of the arrows, to illustrate the hand grip switch and the variable resistance control in circuit with the selector trigger operated switch.
Figure l is a fragmentary cross sectional view taken on the oblique line III-I0 of Figure 1 and looking in the direction of the arrows to show the selector switch and the slide guide controlled by the movement of the hand grip trigger.
Figure ll is a horizontal cross sectional view taken on line II-II of Figure l and looking in the direction of the arrows, to illustrate the shape of the magazine and the manner in which the fastening elements are arranged therein.
Figure l2 is a horizontal cross sectional View similar to Figure 1l, but showing a slightly different fastening element or nail, and
Figure 12A is a horizontal cross sectional View likewise similar to Figure 11 and showing another type of nail in the magazine.
In the drawings, and more in detail, there is shown a semi-automatic hammer and nail set including a housing generally designated in which there is mounted reciprocating motor means generally designated 5 for controlling the movement of the hammer into the path of which nails or other fastening elements are fed froml a magazine generally designated 1. The housing 5 is provided with a pistol hand grip 8 likewise generally designated. 1
The housing 5 is of cylindrical section and is divided diametrically to provide complementary housing sections I0 which are formed of plastic or other insulating material for safety purposes. The hand grip 8 is formed by complementary projections II integrated with the sections I0 so that when the sections are fastened together by fastening elementsrsuch as bolts or the like I2, the hand grip sections II will mate and can be bolted together by similar fastening elements I3. The cylindrical housing formed by the semicylindrical sections I is closed at the rear end by sector-shaped walls I4 formed integral with the respective casing sections. Each of the housing sections I0 is provided with a tapered front Wall portion I5 having a circular cut-away portion I6 to form an opening in the front end of the housing when said sections are placed together.
Further, each of the housing sections I 0 are chambered as at Il and I8 to provide enlarged bores separted by an annular wall I9 extending inwardly a short distance and terminating in a round inner wall 20, thus providing a bore between the housing sections of a size and shape to receive and support a pair of motor casings 2l and 22 that are formed of insulating material and which are threadedly connected as at 23. The motor section 2| is provided with a tapered end wall portion 24 which engages the tapered wall I5 of the housing and projects through the open- 4 ing I 6 to form a barrel 25 of reduced diameter having a central bore 2S.
Electromagnet or solenoid coils 2'! and 28 are mounted on the cylindrical casing sections 2I and 22, with one end of the coil 27 abutting a shoulder 29 on the tapered portion 24, while the other end abutts the annular wall I9 of each casing section. Similarlyy the motor coil or magnet 28 has one end abutting an annular shoulder 3B on the casing section 22, while the `opposite end is held in place by means of a nut 3l on the correspondingly threaded end 32 of the casing section 22,
Reciprocably mounted within the motor casing sections 2i and 22 is an armature 33 which is adapted to be `alternately attracted by the coils A2IV and 28 in a manner which will be presently described.` The forward end of the armature 33 is provided with a longitudinal bore 34 for receiving the rear end of a combined nail set and hammer 35 which is held in place by set screws 35. The free` end of .the hammer or. nail set is mounted to move to and fro within the bore 26 of the barrel 25 and drive nails or other fastening elements projected into the path of said hammer and nail set. The front end of the armature is tapered as at 37 to conform to the tapered wall 24- of the reciprocating motor casing section 2l and thus form a limiting stop for said armature.
In order to feed nails or other fastening elements to the hammer pathway or bore 26 the magazine 'I is arranged on the front of the housing 5, and includes a channelway having side walls 38 connected at one end by a wall 39 having offset portions 40 to provide an enlarged end chamber to accommodate the head of the nail N. The oppositeend is closed by a wall 4I aixed to the forward edges of the walls 38 and the walls are reinforced by triangular shaped ribs I4, A closure 42 is hinged to the rear wall 3,9 as at 43 and a clasp 44 is affixed to the swinging end of the closure and engages a projection t5 on the front wall d I. The upper portion of the magazine 'I is shaped to provide a feed cylinder housing and as shown in Figure 9, the side walls 38 are curved as at i6 to form a housing of circular shape.v The front wall of the upper portion of the wall @I is rounded as at 41 to close the front portion of the cylinder housing and similarly, the rear wall 33 of the magazine is enlarged adjacent4 its upper end to provide a rear disc-like wall 48 for the cylinder housing. The curved walls 46 are provided with extensions 49 which are alxed tothe barrel 25 by screws or the like 55. The rear wall 39 of the magazine 'I has welded or otherwise aflixed thereto a threaded member or nut 52 for receiving a screw 3 extending through a projection on the lower portion of a depending casing extension 53. The casing extension 53 is formed by complementary housing portions each of which is integral with one of the housing sections Ill as shown in Figure 4.
Mounted in the cylinder housing 46 is a feed cylinder comprising a pair of disc-like members 55 connected by a sleeve 56, and each of said disc-like members is provided with a series of peripheral indents 5l to form nail receiving pockets. The feed cylinder is supported upon a pin or screw 5B which is threaded in the rear wall 4-8 of the cylinder housing as shown in Figure 9, and extends through an opening in the front wall M. The barrel 25 is provided with a pair of arcuate slots 59 to permit the cylinder ends to pass at a point below the bore 2B or pathway amc-,cia
of the hammer and addition, thebarrel 2:5 is' cut away as' at 09 to' provide ari-arcuate passag Way communicating the interior of the: cylinder 4:6.r with the hammer pathway or bore 2.8 and thus enable nailsv N tebe projected. into the pathway inv advance' of the hammer 35. The nails N are fed upwardly to the feed cylinder by means of a. follower 6| yieldingly urged Iupwardly by means". of. a sinuous leaf spring 82'.
One of the cylinder ends or discs 55 is provided with a series of projections B3, Fig. '1, which are adapted to be engaged by a. bell crank lever |544 mounted on. a. pin 65 whichhas; its ends received. opposed slots ci;V one in each of the mating faces of. the casing sections |.0.. The bell crank lever 64 is provided with an arm 61 which projects through a slot 88 in the rear wall 48 of the magazine so that its freeV end will be presented to the projections 63 as shown in Fig. 7. A spring 69 is provided for urging the bell crank lever 64 in a direction toward the feeding cylinder, but yet permitting the free end of the arm 61 to slide away from the projections during the retraction of the bell crank lever. A control trigger 10' is mounted on a pin 1| which has its ends received in openings formed in the extensions 53 of the housing sections I0, and said trigger operates in corresponding cutouts 13 in the mating faces of the pistol grip sections An extension 12 is formed onthe trigger 10 and is connected to the bell crank lever 64 by means of a link 14 held in place by pins 15 and 16 on the bell crank lever and extension respectively. A coil spring 11 has one end aflixed to the link 14, and its opposite end anchored to the casing as at 18 to retract the link 14 and cause the arm 61 to be moved downwardly about its supporting pin 65 when the trigger is released.
The pistol grip handle 8 is provided with a bushing 19 through which extends an electric cable 80 which is adapted to be attached to a suitable source of electrical energy. One of the electrical conductors 8| of the cable is electrically lconnected to a switch contact 82 which is supported on a block 83 carried by one of the casing sections while the other electrical conductor 84 iis connected to a slider 85 movably mounted in a :slot 86 so that its contact member 81 will slidably engage an electric resistance element 88. The resistance element 88 is electrically connected by means of a conductor 89 to a switch arm 90a, which is fixed t a support 9| formed integral with one of the pistol grip sections I of the pistol grip 8. A pair of contacts 92 and 93 are carried by the switch arm 90a and areadapted to be alternately engaged by movable contacts 90 and 94 carried by a slide 95 operable in a slide guide 96 suported or formed integral with the casing sections as shown in Figure 10. The slide 95 is provided with an extension 98 which is connected to the trigger 10 by means of a link 99 by suitable pivot pins |00 and |0|. The other end of the slide 95 is provided with an arm |02 in which is mounted a reciprocating pin |03 having an enlarged head |04, which is adapted to engage a stop member on the arm |02 and is yieldingly urged into engagement with the stop |05 by means of a coil spring |06 which has one of its ends abutting the arm |02, and its opposite end in engagement with a washer |01 on the inner end of the pin |03. The extreme inner end of the pin |03 is provided with a contact 94, which is adapted to engage the iixed contact 93 when the trigger is moved outwardly by the spring 11. The contact 90 is electrically connected to one end. of the coil 2 by means of an electrical corr-y ductor |09, while the contact,` 94 is electrically?.
connected to the coil 28' by means of a conduc tor I0. The opposite ends of the coils 21'and 28` are connected together by electrical conductors H and |'|2 which. are connected at |3 and from the point ||3 a conductor extends downwardly into the pistol grip 8, where it is attached to a contact |4 carried by a movable switch arm |I5 which is pivoted as at ||0 on a pivot pin having its' ends mounted: in suitable bearing openings in the opposed sections of the pistol grip. 'The movable arm |l|5 operates. in a. slot |.|1 in the pistol grip, and, a spring |8 is affixed to one of the sections on a projection ||9 and has its free end in engagement with the operating arm |'|5 to normally hold the contacts 82 and |4 separated. f En' Figures 12 and 12A the magazine 1a and 1b are identical. in form to theV magazine 1, but dif-A` ferent forms of nails are shown as being held by the magazines. In Figure 12 the nailv N isf shown as being provided with a countersunk. head, while the nail shown in 112A as at N" isformed with a relatively small head.
In operation, the magazine is iilled with a plu'-V4 rality oi' nails N and the hand grip 8 is grasped which closes the. circuit through the contacts 8-2. and ||4 as shown in Figures l and 2. The bar-I rel 25 is then presented to the work W, Figure 2, and the trigger 19 is depressed to simultaneously rotate the feed cylinder and project a nail into the bore 26 and close the circuit between the contacts and 92. When the contacts 99 and 92 are closed the coil 21 is energized and causes the armature 33 to deliver a power blow through the hammer 35 to the nail projected into the bore 26. The outer part of the barrel 25 is provided with an inclined surface 25a which extends outwardly from the arcuate slot 59 that receives the outer disc of the feed cylinder and this inclined surface facilitates guiding the point of a nail or the like to the bore of the barrel. Upon release of the trigger 10 the trigger and slide 95 will travel forwardly under the inuence of the spring 11 and the contacts 93 and 94 will engage and thus electrically connect the coil 28 to the source of electrical energy and energize said coil. When this occurs, the armature 33 will be retracted to the right hand end of the portable housing I0, and simultaneously the arm 61 of the bell crank lever 64 will move downwardly over the wedge-shaped projections 63 and will be positioned in back of one of the projections as shown in Figure '1 for again moving the feed cylinder upon manual manipulation of the trigger 10.
Should it be desired to cause the hammer 35 to deliver a repeated number of blows without feeding another nail to the bore 26, the trigger 10 is depressed to cause the initial feeding of a nail into the hammer pathway 26 which simultaneously closes the contacts 90 and 92, and causes the coil 21 to be energized as before to deliver a power blow to the nail. Instead of completely releasing the trigger 10, it may be moved forwardly by releasing the pressure thereon slightly as shown in Figure 2 so as to cause the contacts 93 and 94 to be engaged and thus energize the coil 28 and cause the armature 33 and hammer to be retracted. This movement is not sufficient to cause the arm 61 to move an appreciable distance to engage the next or adjacent projection 53 and hence, the trigger 10 may be oscillated by depressing and releasing the same a suilicient amount to cause the contacts 90-92 and 93--94 to be alternately engaged and disengaged. This motion will cause the armature 33 to travel to and fro within the motor casing sections 2| and 22 and strike a series of power blows on the nail N in the work W.
The pivoted arm H5 as has been explained, completes the return circuit from both of the coils to the electrical conductor 8l when the pistol grip 8 is grasped for manipulation.
It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred embodiment thereof, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.
1. In an electric hammer, a portable housing having a hand grip, a barrel on said housing providing a hammer pathway, a hammer reciprocably mounted in said barrel, motor means for reciprocating said hammer in said pathway, a feed cylinder for projecting fastening elements into said hammer pathway, link means for moving said cylinder a predetermined angular distance, and manually operable means on said hand grip for simultaneously controlling the reciprocating movement of said motor means and operating said cylinder.
2. In an electric hammer, a housing having a pistol hand grip, a barrel at one end of said housing providing a hammer pathway, a hammer and nail set reciprocably mounted in said barrel, motor means in said housing, an armature for said motor means connected to said hammer, a cylinder mounted adjacent said barrel for projecting fastening elements into said pathway in advance of said hammer, step by step ratchet means for rotating said cylinder a predetermined angular distance, a trigger operated control switch in said hand grip for controlling said motor means, and linkage connecting said ratchet means to the trigger of said control switch whereby manual operation of said trigger will project a fastening element into said pathway and operate said motor means.
ARTHUR J. CURTIS.
REFERENCES CITED The following references are of record in the le of this patent:
UNITED STATES PATENTS Number Name Date 1,604,220 Davis Oct. 26, 1926 1,694,284 Santa Ana Dec. 4, 1928 1,736,636 Tatar Nov. 19, 1929 1,745,594 Altman Feb. 4, 1930 2,009,580 Govanus July 30, 1935 2,189,700 Britten Feb. 6, 1940 2,315,993 Weyandt Apr. 6, 1943