DE1170338B - Pistol-shaped tool for driving nails or the like. - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Boarding school Class: B 25 c

GERMAN

PATENT OFFICE

EDITORIAL

German class: 87 a-18

Number: 1170 338

File number: L 27553 I c / 87 a

Filing date: May 3, 1957

Opening day: May 14, 1964

The invention relates to a pistol-shaped tool for driving nails or the like.

Such tools are known which have a working piston on its back can be loaded by compressed air, which extends into a working cylinder space via an actuating valve Air storage space flows in, this working piston through at the beginning of its working stroke a mechanical restraint is retained until the air pressure in the air storage space a reached a predetermined value. In addition, the nails to be driven are the Nail ejection channel in which a driving ram fixed to the front of the working piston Is slidably guided, strung together from the side from a magazine on a feed belt fed.

Also known are nail driving tools in which the return stroke of the on its front side the working piston connected to the outside air by generating a negative pressure on the Rear side of the working piston is effected by means of a jet pump, which by means of a control member is connected to the compressed air supply line.

Finally, there are tools of the type mentioned that have a feed pawl, which under Spring loading engages the nail feed belt and depending on the switching movements of the actuating valve for the working piston can be moved back and forth from one another by the distance between two adjacent nails.

The essential part of the invention is that as a mechanical restraint means for the working piston the nail feed belt is provided from which the foremost nail after the at the beginning of the The working stroke of the working piston only takes place when the driving ram is placed on the nail head can be sheared off when the predetermined value of the air pressure in the air storage space is reached.

By utilizing the nail feed belt according to the invention as a mechanical restraint means, significant advantages are achieved compared to tools in which special restraint means for the working piston are used as additional components of the tool. These known tools, which have a special retaining means, are correspondingly more complicated, more susceptible to failure, heavier and more expensive. These disadvantages are eliminated by the proposed invention. Since the resistance of the nail feed belt itself is used as a retaining means for the working piston, the power tool required for driving the nail has to be driven in by a gun-shaped tool
of nails or the like.

Applicant:

Richard Laucher, Canoga Park, Calif. (V. St. A.)

Representative:

Dipl.-Ing. L. Hirmer, patent attorney,

Berlin 31, Katharinenstr. 21

Named as inventor:

Richard Grant Laucher, Canoga Park, Calif.

(V. St. A.)

Claimed priority:

V. St. v. America May 3, 1956 (582 358) - -

automatically add a suitable value for any nail size.

The invention is further explained in connection with the figures of the drawing. It is

F i g. 1 is a side elevation of a nail gun according to FIG the principle of the invention, with parts broken away to show construction details,

F i g. 2 is a vertical section along the line 2-2, with parts broken away,

F i g. 3 is a vertical section along the line 3-3 of FIG. 1, with parts broken away.

F i g. 4, 5 and 6 of FIG. 1 identical representations,

in which the actuation of the valve mechanism and the displacement of the hammer rod from her are shown in their tensioned position in which they are hammering, with parts broken away, F i g. 7 is a cross-section along line 7-7 of FIG

Fig. 1,

F i g. 8 is a horizontal section along line 8-8 in FIG. 1.

It is shown on the fig. 1 referred to. The principle of the invention is applied here for a air powered automatic nail gun 10 is shown. It mainly consists of one Housing 11 with a piston part 12, from a valve housing part 13 and a handle 14. The Housing is made of a light metal, ζ. Β. Cast aluminum. It has a closed pressure chamber 15 at the end of the housing and a piston chamber 16 with an open end, both chambers are aligned coaxially. A piston 17 is

409 589/53

licher is explained. At the initial displacement of the rod 19 its end will cut off part 32 a, which connects the retaining disc to the side of the band 30. Afterwards the knife 42 is with 5 work the straight cutting edges 40 together so that the ends of the tape are cut off, from which the previous retaining washer has been cut off. At the release end of the nail magazine is a tubular protective shield 42 α be

slidably mounted in the piston chamber 16. It consists of a piston head 18 and a hammer rod 19, which is screwed coaxially into the piston head. A seal 20 is mounted in an annular groove 21, which is located on the circumferential surface of the piston head 18. The seal 20 is known Purposes. The upward stroke of the piston 17 in the piston chamber 16 is limited by a stop or a shoulder 22, which on the upper

catch edge of the chamber 16 is formed. How lightly it sets to enclose nail 29 which is in

can be seen and later explained in more detail a plate 43 or the like is to be driven, des-

is, the hammer rod 19 is in a nail driving the same as the hammer rod 19, if the pistol

direction depending on which in the printing is in operation.

Chamber 15 delivered pressure displaceable. The end of the rod 27 which is slidable in the

In the open end of the piston chamber 16 is a 15 piston plate is mounted, has a radial opening

Plate 23 screwed. An axial opening 24 is located or groove 43 α. A pawl 44 is pivotable therein

det is mounted on a pivot pin 45 in the plate 23 for receiving the end. A spring seat 46

the hammer rod 19 which passes through this opening is arranged so that the compression force of the

can go through. End plate 23 also has spring 47 which urges pawl 44 to engage

an opening 25 for connecting the piston chamber 20 to the grooves 31 of the nail band 30 is displaced

16 with the atmosphere, likewise a piston becomes, so that by the axial movement of the rod

Opening 26 for the slidable mounting of one end 27 to the left, seen in FIG. 1, the nail tape

a rod 27, the other end of which is displaced in an opening in the same direction. The Com-

28 is mounted in the bottom of the valve housing part 13, the compression force of a compression spring 48 is applied

so that the rod 47 is perpendicular to the axis of the rod 27 such that it is displaced to the left

Hammer rod is displaceable. will. Is the rod 27 at the end of the opening 26

A number of nails 29 is attached to one, the foremost nail of the nail strip is located 30, which is made of sheet metal, e.g. B. made of carbon tape immediately below the hammer rod 19. low carbon steel. As already suggested, a valve mechanism is used Nail strip 30 is in the form of a tape. He 30 nism 49 to automatically refer the nail tape Alternately place grooves 31 and nail head holding parts, also to drive the hammer rod

32 on. The nail head holding parts have one and the nail in a nail-engaging position with respect to the plate Opening that the nails are thereby held, or the like, which is to be nailed to be driven, which is in a downwardly hanging direction. The valve mechanism is in the present case measure F i g. 8 are welded into it. The nail band 35 from a pistol trigger 50 in the form of a piston, 30 becomes slidable in a nail magazine 33 according to which is slidable in a cylindrical opening the F i g. 2 and 3 worn, which has a U-shaped

Has cross-section and can be formed or stamped from any material. The magazine

33 has a pair of bearing surfaces 34 for holding the 40. The ejection piston 54 has a piston head 55, opposite edges of the nail tape to whichever slidable on the walls of the cylindrical a shift. A cover 35 is used to close the nails and the nail tape in the

Magazine. This is releasable on the valve housing part 13

attached so that it is to the hammer rod 19 in 45-shaped opening 51 on the face of the piston one Nagelzuführstellung is, as this afterwards head 55 has the shape of a pressure chamber 57 a, in becomes even more understandable. which air brought from sufficiently high pressure

It is particularly to the F i g. 7 reference is made to act on the head 55 so that the

took. A pair of scissor plates 36 is pushed by ejector plunger 54 so that it is in a

Screws 37 on the lower surface of the switch-off 50 switch layer is displaced. The piston 54 has a

Closing plate 23 fixed at such a distance, axial opening 58 and a nozzle 59 with an opening

that a groove for the displacement of the nails to the opening 60. The circumferential surface of the trigger

Hammer rod is available. A circular or the piston 50 has a ring 61, which

shaped opening 39 for the passage of the hammer moves to a shoulder 62 in the stop position,

rod 19 is provided therebetween. It forms a 55 The shoulder 62 is on the inner peripheral surface

Cutting edge formed in cooperation with the end of the cylinder opening 51 so as to increase the upward

Hammer bar and a pair of opposing shifting of the handle to limit the opening

aligned cutting edges 40, which with the zen. The trigger also has an annular shape

Opening 39 for cooperation with a groove 63 for mounting an O-shaped ring or

Cutting edge 41 of a knife 42 in connection 60 seal 64 at its upper end, also a

stand, which at the end of the hammer rod 19 annular groove 65 for supporting an O-shaped

is fastened and in an opening of the plate 23 is connected to the ring or seal 66 on the ring 61.

is slidable. The handle 14 is provided with a hose 67

Through the opening 39, the nail head retainer can be. The hose 67 is compressed to a source 32 go through when the hammer rod 65 mated air is connected. An opening 68 is located against the nail head with such a force is manageable. She stands with the cylinder pushing is that the retaining disk 32 is cut from the band 30 opening 51 at an annular groove 69 in connection will, as will be explained later, which in the circumferential surface of the pistol

51 is mounted in the valve housing part 13. The trigger gun has an axial opening 52 for storage a slide 53 of a discharge piston assembly 54.

Opening 51 is. A seal 57 for the known purposes is mounted in an annular groove 56 which is provided in the piston head 55. The cylinder

pusher 50 is formed. A pair of transverse openings 70 lead from the annular groove 69 into the axial opening 52 of the pusher. A pair of transverse openings 71 are also provided in the stem 53 of the piston 54 at the outlet opening of the nozzle 59. A pair of O-shaped rings 72 and 73 are supported in annular grooves 74 and 75 on opposite sides of these transverse openings 71. A seal 75 α is located at the upper end of the stem 53 in an annular groove 75 b.

The pressure chamber 15 is connected to the cylinder opening 51 on the piston stop 22 through an opening 76 connected so that compressed air enter the pressure chamber for actuating the piston 17 can. This will be discussed later. The ejector piston assembly has a downward slope extending, tubular leg part 77, which by a pin 78 with one leg 79 of a Swivel link 80 is pivotally connected. The pivot link 80 is supported so that that it can swing about the axis of a retaining pin 81, which of the valve housing part 13 is worn. The other leg 82 of the pivot link 80 is through a pin

83 connected to the switching or adjusting rod 27 so that it is under pressure against that of the Compression spring 48 exerted force in response to the downward displacement of the ejector piston assembly 54 is moved. It should be noted that the pawl 44 is designed to have its engaging hook

84 above the nail head and the nail band when shifting the switching rod 27 to the right is moved in the same direction. Since the nail gun only has to drive in one nail at a time, is it required to see to it that only one nail is in the driving position to the hammer rod after each Nailing process is postponed. A screw 85 is used for this purpose. It is in the stop position to the leg 82 of the pivot link 80 such that the pivoting of the pivot link is limited in this direction to a certain value so that the shift rod 27 can move to the right to an extent that is only sufficient that the hook 84 of the Pawl 44 is moved into the adjustment or switching groove of the subsequent nail.

As previously mentioned, the basic principle of the automatic nail gun according to the invention is based on the inertia of a piston moving at high speeds. This inertia is used to drive a nail into a workpiece surface. To operate the gun, pressurized air at approximately 6 to 7 kg / cm ^{2 is} supplied to valve mechanism 49 via hose 67 and port 68. In the normal rest position of the trigger 50, the valve mechanism and the piston 17 take the action shown in FIG. 1 position shown. The compressed air entering the annular groove 69 is completely trapped by the O-shaped rings or seals 64, 65, 72 and 75 α , which ensure that the air does not enter the valve. So the air is kept at the line pressure. If the pusher 50 is moved downwards by the operator (see FIG. 4), the compressed air reaches the pressure chamber 57 a and into the pressure chamber 15 via the opening 76, where it acts on the end face of the piston head 18. It should also be emphasized that the compressed air also acts on the piston head 55 of the ejector piston 54. Since the compressed air can only get into the piston chambers 15 and 57 α , the force exerted on the end face of the piston head 55 of the ejector piston 54 is increased to a value at which the ejector piston 54 can move downward so far that the swivel link 80 is pivoted to the stop screw 85. Here, as already mentioned, the hook 84 of the pawl 44 is pivoted from its engagement with the switching groove 31 between the first and second nail to an engagement between the switching groove between the second and third nail (FIG. 5). At the same time, the air pressure in the

Is chamber 15 increased so that sufficient force is exerted on the face of the piston head 18 to hold the strip 30 during shifting or switching and to press the hammer rod 19 against the head of the nail which is in the driving position with respect to the hammer rod until the nail head holding portion 32 is cut from the nail strip 30 (Fig. 6). The nail 29 and its holding part 32 are then released with the hammer rod 19 and the piston head 18. It should be emphasized that the energy stored in the pressure chamber 15 before the cutting of the holding part 32 from the rest of the tape 30 is sufficient after the cutting process has taken place, the piston 17 and the nail 29 as a rapidly accelerating mass in the direction of the workpiece surface to be nailed to drift. During the displacement of the hammer rod 19 in the downward direction, the cutting edge 41 of the knife 42 contacts the nail tape 30 and cuts off the end strip. There is an opening 86 in the protective shield 42 a so that the end strip can be released from the protective shield.

The speed of the piston head 18, the hammer rod 19 and the nail 29 increases during the covering of the path from the tensioned or erect position in the contact position of the Nagels with the workpiece surface to be nailed because of the sudden release of energy in the Pressure chamber 15 closed. Since the kinetic energy of the rapidly moving mass is used to To drive the nail into the workpiece surface, the piston can be made from a relatively light Material and be manufactured in a lightweight construction. The weight of the pistol can also be proportionate be light. It should also be emphasized that, as a result, a light pistol for driving the Nails can be used which are only in operation by a minimal amount apart from the Moved workpiece surface and consequently reduced operator fatigue.

When the hammer stroke or the nailing process has ended, the operator presses the trigger 50 free. This opens the transverse openings 71 for the pressure chambers 15 and 57a (FIG. 6). In addition, the transverse openings 70 are opened so that compressed air enters the orifice 60 the nozzle 59 arrives. The compressed air passing through the orifice 60 of the nozzle 59 acts as a Pump and suck the air in the pressure chamber 15 through the transverse opening 71 into the atmosphere. It arises a low pressure vacuum in the pressure chamber 15. The piston head 18 is in its upper starting position at the stop 22 by the

atmospheric pressure, which the lower end face of the piston head 18 through the opening 25 the end plate 23 is applied therethrough. Due to the pressure differential between the pressure in the Pressure chamber 15 and the atmosphere, the KoI-ben is returned to its upper end position.

The pressure chamber 57 a is also vented by the pumping action of the nozzle, so that the pressure differential between this chamber and the atmosphere, as well as that exerted by the spring 48 Force influence the ejector piston 54 so that it is again in accordance with its raised position F i g. 1 assumes after the end of the hammer rod 19 in its starting position above the Strip 30 has been returned. In this way, the pivot link 80 is pivoted so that that the adjusting or switching rod 27 is moved to the left. The latch moves the the following nail in the drive-in position to the hammer rod. The hammer bar has once again its upper end position is taken, as is the piston 54 in its rest position, in which the seals 64, 65, 72 and 75 a hold the air trapped at line pressure. The lower part of the valve housing part 13 is connected to the atmosphere through openings to release the air from opening 58. An O-shaped ring 87 is located on the inner end face of the end plate 23 around the joint of the piston head 18 when it is pressed in its direction for hammering.

It is clear that the product of the pressure stored in the chamber 15 and the area of the Piston 17 determine the cutting force of the piston and also the volume of the chamber 15 for a certain chamber pressure represents the potential energy, which in a kinetic energy is convertible. Thus, the volume of the chamber 15 can be changed to provide a sufficient driving force for different nail sizes, provided that the same Strip is used.

The invention uses the strip 30 to hold the plunger 17 back until sufficient potential energy is present in the chamber 15. This energy builds up proportionally slowly through the line and valve constrictions. If this holding effect were not available, the piston would start moving the nail immediately after the fluid was introduced into chamber 15. After the nail is engaged with workpiece surface 43 the nail gun would be moved away from the surface 43 because of the reaction energy of the light gun is less than the energy required to drive the nail.

The composition, the thickness and the cutting length of the strip part 32 a determine the cutting force, which is required to free the connecting part 32 and the nail 29 from the strip. It any strip can be selected for a particular nail gun, or an appropriate one can be selected Piston area, piston volume and line pressure are selected for a nail gun, to be able to use a certain strip construction.

The fluid motor according to the invention, consisting of the valve mechanism and the Piston assembly, can be used for various other systems in which only in one direction an operation is to be carried out with the aid of pressure. For example you can do this this way can be attached with the aid of air brackets. The ejector return of the piston assembly happens quickly. The advantage here is that the fluid motor works in both directions is operated via a single cylinder bore by a main pressure source. As a result of use For the ejector return, a large opening can be used around one side of the piston head 18 to connect with the atmosphere, so that no pressure against the piston head at his Working stroke is established. When using pistons that work in both directions, a large valve mechanism would be needed to release and deliver the fluid to steer through such a large opening. It is also clear that the normal distance between the end of the nail 29 and the workpiece surface is sufficient that the lightweight piston structure can accelerate and convert the potential energy in the chamber 15 into kinetic energy of the light piston.

Various changes can be made by those skilled in the art without this departing from the meaning and Scope of the invention is varied according to the appended claims.

Claims (3)

Patent claims: 1. Pistol-shaped tool for driving nails or the like with a working piston, which can be loaded on its rear side by compressed air, which via an actuating valve into a the working cylinder space expanding air storage space flows in, and at the beginning of his Working stroke is held back by a mechanical restraint device until the air pressure in the Air storage space reaches a predetermined value, the nails to be driven into the nail ejection channel, in which a driving ram fixed to the front of the working piston Is slidably guided, strung together from the side from a magazine on a feed belt are supplied, characterized in that the nail feed belt is used as a mechanical restraint means for the working piston (17) (30) is provided, from which the foremost nail after being placed at the beginning of the working stroke of the working piston (17) of the driving ram (19) on the nail head only when the predetermined value is reached the air pressure in the air storage space (15) can be sheared off. 2. Tool according to claim 1, wherein the return stroke of the on its front side with the Outside air related working piston by generating a negative pressure on the Rear side of the working piston is effected by means of a jet pump, which by means of a control member can be connected to the compressed air supply line, characterized in that the jet pump (60) is mounted in a control slide (54) forming its control member, which is in a as Actuating valve for the working piston (17) provided, push-button slide (49) that can be moved into the open position by finger pressure is arranged coaxially relative to this displaceable and depending on the switching movements the push-button slide is automatically moved to one or the other end position, in which the jet pump (60) is switched on or off. 3. Tool according to claim 1 and 2, with a spring loaded in the nail feed belt intervening, depending on the switching movements of the actuating valve for the working piston by the distance between two adjacent nails from each other movable back and forth feed pawl, characterized in that the IO Feed pawl (44) sits on a feed rod (27), which by means of one on it and the free end of the control slide (54) for the jet pump (60) articulated angle lever (80) can be pushed back and can be advanced by a spring (48). Considered publications:
U.S. Patents Nos. 1014 639, 1567 554,
501.1746 496.1939 632, 2 290 256, 2 241184, 425 494, 2 445 674, 2 625 682.2 698 938.2 729 198; French Patent No. 913,697;
British Patent No. 599 544. 1 sheet of drawings 409 589/53 5.64 © Bundesdruckerei Berlin