US3531037A - Bolt setting tool - Google Patents

Description

Sept. 29, w70 F. SCHNEIDER BOLT SETTING TOOL Filed oct. 2, 1967 3 Sheets-Sheet 1 //V l/E/V TOR FR/TZ SCH/VE/DER ATTORNEYS F. SCHNEIDER BOLT SETTING TOOL Sept. 29, 1970 Filed Oct. 2, 1967 5 Sheets-Sheet 2 t m/VE/VTOR )fR/r2 scHn/E/DER PEA/DLErO/v, NEU/WAN 5y SE/BOLD 8 W/LL/MS ATTORNEYS United States Patent O 3,531,037 BOLT SETTING TOOL Fritz Schneider, Bavaria, Germany, assignor to Impex- Essen G.m.b.H., Ansbach, Germany, a limited-liability company of Germany Filed Oct. 2, 1967, Ser. No. 672,301 Claims priority, application Germany, Oct. 3, 1966,

Int. Cl. Bzsc 1/14 U.S. Cl. 227- 9 Claims ABSTRACT OF THE DISCLOSURE A bolt setting tool for driving bolts, pins or similar fastening or securing means into surfaces of construction materials, which includes a barrel for containing the bolt, a piston for driving the bolt in the barrel, a cartridge and associated firing mechanism and combustion chamber for providing explosive impetus to the piston on firing of the cartridge, which tool is characterized by adaptability for a variety of bolt sizes, safety, simplicity of operation and reduced tendency to accumulate powder residue which would interfere with smooth operation of the piston and driving mechanisms.

BACKGROUND OF THE INVENTION This invention relates to a bolt setting tool for driving bolts or similar fastening means solidly into various construction materials and surfaces. More particularly the invention relates to a bolt setting tool which is provided with a piston that is operated by the explosion of a cartridge. The type of tool provided herein includes a movable barrel for containing the bolt, a piston located in the barrel having a driving surface or shank at one end in contact with the bolt, and a cartridge seat or combustion activated piston surface at the other end in cooperative relation with a combustion chamber which in operation drives the piston and bolt forward with a short driving stroke. Because of the longitudinal travel of the barrel with the present bolt setting tool and the feature of a xed ignition point of the charge, bolts of different lengths can be put into the barrel or against the front face of the piston in such way that the tip of the bolt in the ignition point position of the piston and associated combustion chamber bushing, sits exactly at the provided drive-in spot. The path of travel of the barrel provided must thus be of approximately the length for tting to bolts having a variety of lengths and this makes necessary a correspondingly long spring for the spring mounting of the barrel against the tool housing. The combustion chamber bushing has only a comparatively short driving stroke, which means that the power gas that arises from the combustion chamber only acts upon the piston for a comparatively short axial distance, and then it expands quickly by virtue of the construction and ilows sideways and out of the chamber. Therefore, only very little residue of powder deposits in the short bore of the combustion chamber or combustion chamber bushing which in turn guides the rear end of the piston. Accordingly, the use of the bolt setting tool, especially the setting of bolts and the thereby following back-stroke of the piston, are rather facilitated.

An already known bolt setting tool of this general type has a combustion chamber with an axial short shell, open at both ends, and in which the rear end of the piston is to push in from the front and from the other end of which a recoil damper projects. The cartridge is placed laterally in about the middle of the combustion chamber and transverse to the chambers axial longitudinal direction. The firing pin provided for firing the cartridge is also principally placed vertically or at right angles to the moving direction of both piston and recoil damper in the handle. The handle also houses the rest of the firing mechanism. For inserting and ejecting, respectively, of the cartridge and cartridge case, the handle must be lifted, which causes corresponding diiculties in construction and use. As the combustion chamber bore is open not only in the front but also in its rear end and, further, at the firing of the cartridge not only the piston but also the recoil damper leaves the combustion chamber, the deposit of an unburned residue of powder is inherent in the system. This residue in time will cause the parts which are to move into the combustion chamber, especially the piston, to run heavy.

SUMMARY OF THE INVENTION Accordingly, it is one asp-ect of the present invention to provide a bolt setting tool with a short-stroke combustion chamber and bushing of the before-mentioned type which does not show the above defects but works unobjectionably in spite of a comparatively very simple construction and that especially 4makes possible a simpler inserting of the bolts and the thereby necessary relative pushing-in of the piston in cooperation `with the combustion chamber bushing. This invention is substantially attained by providing a combustion chamber bushing which is closed at its rear end except for receiving the tiring mechanism or firing pin. Furthermore, the combustion bushing is horizontally movable within a breechblock, so that at the ring of the cartridge which lies between the piston and the combustion chamber bushing, the bushing is disposed rearwardly within the breechblock. As the combustion chamber bushing is, after ring, only open in the front for the reception and guiding of the rear end of the piston, soiling of the combustion chamber by residue of powder is completely avoided. This is obviously due to the combustion temperature that is comparatively high in the present invention; thereby, first, the powder is burned more cornpletely and, second, premature powder-gas condensation is avoided.

According to a further aspect of the present invention, the part of the breechblock which lies in front of the combustion chamber bushing is provided with a charging hole that surrounds the rear part of the piston and at the same time is a space for the expanding gas. Further, the breechblock is placed in the housing which has a correspondingly arranged charging aperture adjustable by turning in such a way that its charging hole is shut by the housing and in this shut position the firing mechanism of the combustion chamber bushing can be operated. In this manner both the charging operation as well as the ejection of the empty cartridge case are facilitated.

The total result of the combination of the short piston ring stroke and the combustion chamber bushing closed at its rear portion is that after the rear portion of the piston has been driven from the combustion chamber the powder gas expands without restraint into the rather large expansion space formed by the charging hole. The eventual deposit of powder or gas residue in the large charging hole does not interfere with the operation of the bolt setting tool, particularly as any such residue can easily be removed through the opened charging hole. In any event, the burning of the powder is substantially improved by the rearwardly closed short-stroke combustion chamber bushing and the forwardly placed, rather large charging hole, because the expansion of the powder gas from the combustion chamber in only one direction makes the burning temperature fall an inconsequential degree.

The cartridge which is between the combustion chamber bushing and the piston should, in the preferred embodiment, be placed in the rear end of the piston, though it is also possible to put it into the combustion chamber with its ignition rim facing toward the piston.

The bolt setting tool of the present invention is preferably provided with a hand trigger that releases the firing mechanism. However, it also can be tted for corresponding hand-hammer operation. For this purpose 1t will be advantageous to make the breechblock with charging hole turnable and axially adjustable against the housing by means of a steep thread; thereby, the -firing pin which penetrates the rear parts of the combustion chamber bushing and the breechblock at ignition positlon, extends through the back of the housing for reception of the ignition stroke.

According to a further aspect of the invention, a spring is provided in the cylindric casing of the breechblock which surrounds the charging hole. This spring is d1sposed and operates axially parallel to the bore and urges the mouthpiece and piston assembly to hold the same away from the breechblock to the most forward position. As the breechblock contains in its front part the charging hole and in its rear part the combustion chamber bushing with the firing mechanism, it has a rather long axial dimension. The spring, therefore, can easily be compressed in the casing of the breechblock so that travel of the barrel is accommodated by a corresponding length of the spring travel in the fitting of bolts of different lengths without lengthening the whole tool.

lFor a more complete understanding of the invention, reference is made to the drawings in which:

FIG. 1 is a vertical longitudinal cross section view of the new bolt setting tool of this invention, showing piston and mouthpiece in front charging position;

FIG. 2 is a section according to FIG. 1 but with the tool parts in firing position;

FIG. 3 is a top plan view of the tool shown in FIG. 1;

FIGS. 4 and 5 are vertical sections along the line A-B- C-D of FIG. 3, respectively illustrating the shut and opened charging hole;

FIG. 6 is a fragmentary view in partial section of a portion of the rear end of a modified piston for use in this invention showing a combustion chamber formed therein;

FIG. 7 is a fragmentary sectional view of a modified bushing with the cartridge placed in it for use with the modified structure of FIG. 6;

FIG. 8 is a further embodiment of the bolt setting tool of this invention in transverse cross section, which is fired by hand-hammer operation; and

FIG. `9 is a cross sectional view of FIG. 8 taken along the line A-B.

Referring to FIG. 1 of the drawings, there is illustrated a bolt setting tool 10 in accordance with the present invention, comprising a housing or casing 12, in generally cylindrical form enclosing a breechblock 14 movably or slidably and rotatably disposed within the housing 12. The breechblock 14 is contained within the casing at the rear portion 15 by means of a cap 16 secured to the housing 12 and a rubber buffer or snubber or other resilient means 17 interposed between the cap 16 and the rear portion 15 of the block 14. The breechblock 14 contains a charging hole 18 which is readily accessible in the charging position of the breechblock as shown in section in FIG. 5 through the charging window 18a shown in that figure formed in the housing 12. FIG. 4 shows the charging window closed by partial rotation of the breechblock 14 to the closed position. In FIG. l the charging hole 18 `is also shown in the closed position forming a charging cavity which also functions as an expansion chamber for gas formed by the explosion of the cartridge used to provide driving force.

A bushing 24 is illustrated, having a combustion chamber 22, facing forwardly, and is slidably disposed within a cavity 20 formed within the breechblock 14. The bushing mounted for longitudinal sliding movement within the cavity 20 is urged forwardly from the breechblock by means of a spring 25. The breechblock 14 is also provided with a centrally located bore 26 in which the rearward portion of the ring pin 27 is slidably disposed. The pin 27 is urged forwardly by a spring 28 disposed within the cavity formed at the rearward end 15 of the breechblock 14 and is supported at the rearward portion thereof against the cap 16 forming a closure in the housing 12. A shoulder 27a limits forward movement of the pin 27 with respect to the block 14 by abutment against the constriction 26a of bore 26. The bushing 24 is also provided with a relatively small aperture 29 also adapted to slidably fit the forward portion 30 of the ring pin 217. The forward pin portion 30 is of reduced diameter with respect to other rearward portion of the pin 27 and lits within the aperture 29 formed in the bushing 24. This aperture extends to the rearward portion of lthe combustion and ring chamber 22 formed in the bushing 24 and is adapted to strike the rearward portion of a cartridge, as hereinafter described, when the bolt setting tool is assembled in firing position, as shown in FIG. 2.

A barrell or bolt holding structure 32 of generally cylindrical shape having formed therein a central bore 34 is provided, which barrel is slidably disposed in the cylindrical aperture 14a formed at the forward end of the breechblock 14. The barrel is secured within the breechblock by ringnut 36 axed to the forward end of breechblock 14, i.e., aperture 14a and by the shoulder 32a formed at the rearward end of the barrel 32.

A piston 38 having a forward portion 39 and drive face 39a at the forward end is disposed in the bore 34. The forward portion 39 is shaped to fit in smooth sliding relationship to the surface of the aperture or bore 34 and is adapted to drive a bolt or similar fastener 40 disposed in the forward end 32b of the barrel 32. The rearward end of the piston 38 is provided with an enlarged sector or driving plug 42 containing a cartridge cavity 44. The enlarged sector or driving plug 42 is sized for sliding fit into the cavity 22 of bushing 24. A cartridge may be placed in cavity 44, which cavity is chamfered to receive a suitable cartridge. A spring 46 is disposed in ya cavity of the breechblock 14 to supply spring tension between -the barrel 32 and breechblock 14. The barrel 32 containing bolt 40 and piston 38 is forced rearwardly in breechblock 14 against spring 46 until plug 42 engages the combustion chamber or cavity 22 in bushing 24 and the assembly of barrel 32, piston 38 `and bushing 24 are urged rearwardly against spring 25 until in firing posinon, as shown in FIG. 2, by pressure on the muzzle piece 50. The firing pin 30 is prevented from striking a cartridge in the cartridge holder by means of a retaining element or scar 52 which is urged downwardly in slot 54 of breechblock 14 by spring S6.

When in the firing position, as shown in FIG. 2, the Sear 52 may be raised by trigger mechanism 48, releasing the firing pin 30, and thereby driving the piston forward by means of the explosion of a cartridge activated by the pm 30. In order to make certain that the tool can be fired only when in position, as shown in FIG. 2, when charging hole 18 is completely shut, a cross slot 58 and a longitudinal slot 60 are provided. A guide pin 62 is provided and catches the slot 58 when the tool is in the open posltlon, as shown in FIG. l, but when the tool is in the closed position (FIG. 2) the breechblock is rotated and the pm 62 passes out of the ring slot 58 into longitudinal slot 60 and the scar 52 is positioned over the trigger 48. See also FIGS. 4 and 5 for the closing arrangement.

The tip of the screw 62 engages the annular groove or slot 38 until the breechblock 14 is rotated, relative to the housing 12, bringing the longitudinal slot 60 into alignment with the tip of the screw 62. Then the breechblock can be slid rearwardly in the housing.

In operation, a cartridge is inserted into the cartridge cavlty 44 at the rearward end of the piston 38. The cartridge is loaded through the aligned window 18a in the housing 12 and hole 18 in the breechblock 14. Thereafter the breechblock 14 is rotated relative to the housing 12, and the muzzle piece 50 is pushed against the work. The bolt 40 is driven into the work when the trigger 48 is pulled. Then, by grasping the forward protruding end thereof, the breechblock 14 is rotated tothe loading position, and the expended cartridge is allowed to drop out of window 18a.

FIGS. 6 and 7 show alternate embodiments of this invention wherein the rear end -64 of the piston 38 is provided with a combustion chamber 66 (see FIG. 6) which slidably fits the forward end 68 of modified bushing 70 (shown -as a fragmentary view in section in FIG. 7). In this embodiment a cartridge accommodating formation 72 is provided on the bushing and the pin 30a strikes the cartridge rim (for rim re cartridges) as shown. The assembly otherwise s the same as shown in FIGS. 1 and 2.

In FIG. 8 an alternative embodiment is s hown where a firing pin is driven by hammer pressure. In this embodiment the breechblock 74 is rotatable against the housing 76 by means of a. steep thread which serves to rotate the breechblock and close the charging hole 78. The firing pin 80 is driven forward by a hammer blow on the projecting end 82 which protrudes from an aperture 84 formed in end cap 86. This drives the pin 80 forward in bushing 88 exploding the cartridge in the cavity 87 of end 89 of piston 90 closely fitted into the combustion chamber 85 of 'bushing 88. The piston 90 is driven forward with the bolt 92 and the gases escape from chamber 85 to charging hole chamber 78 then in closed position, as shown in FIG. 4.

FIG. 9 shows a section along the line A-B of FIG. 8 where the charging port 78l is in the open or charging position.

While several particular embodiments of the invention have been illustrated in the foregoing, it will be appreciated that other embodiments may be provided which do not depart from the true spirit and scope of this invention and such embodiments are intended to be included herein.

I claim:

1. A bolt fastener setting tool for driving bolts into construction materials by means of a piston driven by a cartridge explosion which comprises:

(a) a housing of generally hollow cylindrical form,

(b) a breechblock rotatably and slidably disposed within said housing and having a bushing cavity formed in the forward end thereof,

(c) a bushing slidably disposed within the` cavity of the breechblock, and having a forward-facing first chamber portion therein,

(d) a barrel slidably cooperating with the breechblock and having an axial bore adapted to hold a bolt or other fastening means,

(e) a driving piston disposed at one end in said barrel in driving relationship to a bolt disposed therein,

(f) a second chamber portion formed in the other end of the piston, juxtaposed with said lirst chamber,

(g) said first and second chamber portions forming a combustion chamber, and

(h) a firing pin mechanism slidably disposed within said bushing for discharging the cartridge whereby explosive gases from said cartridge force the said other end of the piston in bolt driving fashion.

2. A bolt setting tool according to claim 1 wherein the second chamber portion of said piston includes a rearwardly facing first cavity formed at the other end thereof and the bushing has a corresponding element for iitting relationship into said first cavity, said first chamber portion being formed in said element.

3. A bolt setting tool according to claim 1 wherein the first chamber portion is a forwardly facing cavity formed in the bushing, the rearward end of which is adapted to receive a firing pin from the firing pin mechanism.

4. A lbolt setting tool according to claim 1 wherein the breechblock and housing have a charging cavity formed therein forward of the combustion chamber formed by the associated piston and bushing and adapted to receive explosive gases from the combustion chamber after the other end of the piston is driven forwardly and away from the bushing.

5. A bolt setting tool according to claim 4 wherein means are provided to render the firing mechanism operative only when the housing has been rotated with respect to the breechblock to place the charging hole in the breechblock out of register with the corresponding charging hole in the housing to form thereby a discharge cavity for the reception of explosive gases from the combustion chamber` 6. A bolt setting tool according to claim 1 wherein a spring means is provided between the barrel and the breechblock to accommodate barrel travel of varying amounts when bolts of varying dimensions are used.

7. A bolt setting tool according to claim 1 wherein one of said combustion chamber portions is disposed for close sliding relationship within the other of said combustion chamber portions.

8. A bolt setting tool according to claim 4 wherein an end of the firing pin selectively protrudes from the housing at the end opposite the barrel for impact tiring by a hammer.

9. A 'bolt setting tool according to claim 8 wherein the housing and breechblock are in coarse threaded engagement and have respective charging holes which are aligned in one position of relative rotation, whereby rotation of the said housing and breechblock to another position of relative rotation closes the charging hole in the breechblock and causes the said end of the firing pin to protrude from said housing.

References Cited UNITED STATES PATENTS 2,768,375 10/1956 Catlin 227-11 3,016,539 1/1962 Marsh et al. 227-10 3,104,396 9/1963 Termet 227-10 3,171,131 3/1965 De Carlo et al 227-10 3,323,705 6/1967 Grotsch et al. 227-10 XR GRANVILLE Y. CUSTER, JR., Primary Examiner

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