US3494531A - Pin setting device using electrically detonatable cartridges - Google Patents

Description

Feb. 10, 1970 HANS-DIETER SEGHEZZI 3,494,531

PIN SETTING DEVICE USING ELECTRICALLY DETONATABLE CARTRIDGES 3 Sheets-Sheet 1 Filed Feb. 28, 1967 Qm m 3% VM INVENTOR. HANS- 'IER SA'GHEZZ/ ATTORNEYS Feb. 10, 1970 HANS-DIETER SEGHEZZI 3,494,531

PIN SETTING DEVICE USING ELECTRICALLY DETONATABLE CARTRIDGES Filed Feb. 28, 1967 3 Sheets-Sheet 2 CURRENT SOURCE FIG. 5 BY Feb. 10, 1970 HANS-DIETER SEGHEZZI 3,494,531

PIN SETTING DEVICE USIIiG ELECTRICALLY DETONATABLE CARTRIDGES Filed Feb. 38, 1967 (5 Sheets-Sheet 3 A Tron/vars 3,494,531 PIN SETTING DEVICE USING ELECTRICALLY DETONATABLE CARTRIDGES Hans-Dieter Seghezzi, Vaduz, Liechtenstein, assignor to Hilti Aktiengesellschaft, Schaan, Liechtenstein Filed Feb. 28, 1967, Ser. No. 619,241 Claims priority, application Great Britain, Mar. 5, 1966, 9,729/ 66 Int. Cl. B25c 1/08 U.S. Cl. 2279 8 Claims ABSTRACT OF THE DISCLOSURE A cartridge-operated setting device for driving fastening means, such as nails, pins and the like, into hard receiving materials, such as concrete and steel, by the detonation of an electrically detonated cartridge is formed with a guide portion, for the fastening means, a handle portion, and a cartridge chamber, and the detonation of an electrically detonatable cartridge in the cartridge chamber projects a piston or the like to drive the fastening means into the receiving material.

A pair of electric terminals is provided at the cartridge chamber in insulated relation to each other, and an electric detonating circuit is provided for connection to a source of electric potential, this detonating circuit includ ing respective conductors connected to the terminals. At least one safety switch means is connected in the detonating circuit and is closed only when the parts of the device are in position to drive a fastening means. Furthermore, at least one device actuating switch is connected in the circuit and to the safety switch means in such a manner that both the safety switch means and the actuating switch must be closed for the device to be actuated.

In one embodiment of the invention, the device is arranged to be connected to an external source of electric potential and, in another embodiment of the invention, a source of electric potential is mounted or enclosed in the device. In this latter embodiment, a charging condenser is included in the detonating circuit and is charged to a relatively high voltage when the actuating switch has one of two positions, this condenser discharging through the detonating circuit and through the electrical terminals when the actuating switch has its other position and the safey switch means is closed.

BACKGROUND OF THE INVENTION Known cartridge-operated setting devices for driving fastening means into hard receiving materials use cartridges which are detonated by percussion impact. In order to prevent undesired detonation, such a device must comprise a relatively expensive detonating mechanism and associated safety devices. There is a distinct disadvantage, both from the standpoint of economics and from the standpoint of safety, with respect to setting devices using impact-detonated cartridges.

SUMMARY OF THE INVENTION The invention relates to cartridge-operated pin setting devices for the driving of fastening means, such as nails, pins and the like, into hard receiving materials such as concrete and steel, and, more particularly, to an improved cartridge-operated pin setting deviceutilizing electrically detonated cartridges.

The cartridge-operated setting device of the invention is intended as a simple and safe setting device for these fastening means, and the safety is enhanced by the use of electrically detonated cartridges. The use of electrically detonated cartridges, as compared to the percussion- States Patent detonated cartridges, has certain advantages with respect to both the cartridge and the setting device proper.

In accordance with the invention, a cartridge-operated pin setting device comprises housing means including a guide portion, a handle portion and a cartridge chamber. Two electrical terminals are provided at the cartridge chamber and are insulated from each other, and a detonating circuit is provided for connecting the terminals to a source of electric potential, this detonating circuit including respective conductors connected to the terminals. The detonating circuit further includes at least one safety switch means which is closed only when the parts of the device are in position to drive a fastening means, and also includes at least one device actuating switch connected to the safety switch means in such a manner that both the safety switch means and the actuating switch must be closed in order for the device to be actuated to drive a fastening means.

The two terminals arranged at the cartridge chamber are so positioned that they are cngageable with the terminals of an eletcrically detonated cartridge positioned in the cartridge chamber. The safety switch means assures that detonation of the cartridge is possible only if the device is pressed against a receiving material with a certain minimum pressure. The electrically detonatable cartridge is so designed that it can be detonated only at a preset minimum voltage or amount of ignition energy, but cannot be detonated by a percussion impact. Thus, the pin setting device of the invention does not require the ignition pin required in known devices, nor does it require the moving parts associated with the ignition pin.

The pin setting device of the invention may be connected to any current source which, either directly or through a transformer, will supply the required ignition potential or energy. For certain kinds of use, wherein connection of a commercial supply circuit is not possible, it is advantageous, according to one embodiment of the invention, to install the current source either in or immediately adjacent the setting device. In this case, a particularly suitable current source is a rechargeable battery having a capacity advantageously selected so as to permit the driving of at least 1000 fastening means before recharging of the battery becomes necessary. In such event, recharging may be effected overnight. When utilizing such a battery, known means for transforming the potential are used.

In accordance with a further feature of the invention, it is advantageous to use a condenser and to construct the device actuating switch so as to have two switching positions. In one position, the device actuating switch closes a circuit including the current source and the condenser, for charging of the condenser. In its other position, the device actuating switch electrically connects the condenser to the cartridge chamber terminals. In the latter position, if the safety switch means is closed simultaneously with the actuating device closed to the firing position, the condenser discharges through the electrically detonated cartridge in the cartridge chamber, thus detonating the cartridge.

An object of the invention is to provide a simple and safe pin setting device.

Another object of the invention is to provide a simple and safe pin setting device designed to use with electrically detonated cartridges.

A further object of the invention is to provide a cartridge-operated setting device, for use with electrically detonated cartridges, and having advantages with respect to both the cartridge and the device proper.

Yet another object of the invention is to provide a cartridge-operated pin setting device including housing means having a guide portion, a handle portion and a cartridge chamber, and further including electrical terminals at the cartridge chamber and insulated from each other.

A further object of the invention is to provide such a pin setting device including a detonating circuit for connecting the terminals to a source of electric potential, with the detonating circuit including at least one safety switch means and at least one device-actuating switch.

Still another object of the invention is to provide such a cartridge-operated setting device utilizing electrically detonated cartridges which can be detonated only upon the application thereto of at least a minimum preset potential.

A further object of the invention is to provide a cartridge-operated setting device using electrically detonated cartridges and arranged for connection to an outside source of potential.

Still another object of the invention is to provide a cartridge-operated setting device utilizing electrically detonated cartridges and having a self-contained source of electric potential.

An ancillary object of the invention is to provide a cartridge-operated setting device utilizing electrically detonated cartridges and which does not require the moving parts necessary with setting devices utilizing percussion impact detonated cartridges.

BRIEF DESCRIPTION OF THE DRAWINGS For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a longitudinal sectional view through one form of a cartridge-operated setting device embodying the invention, and showing .a source of electric potential connected thereto;

FIG. 2 is a schematic wiring diagram related to the device shown in FIG. 1;

FIG. 3 is a partial longitudinal sectional view through another form of cartridge-operated setting device embodying the invention;

FIG. 4 is a schematic wiring diagram related to the setting device shown in FIG. 3; and

FIG. 5 is a complete wiring diagram related to the setting device shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, the pin setting device 1 shown therein comprises a hollow body 2 which is closed at one end. A handle 3 projects laterally from body 1 close to the closed end of the latter. At its closed end, body 2 is formed, in its interior, with an annular groove 4 defining a projection 5 having two parallel bores 6 and 7 therethrough to receive current conductors. The forward ends of bores 6 and 7 are formed with large recesses to receive dielectric material 8 for the cartridge chamber terminals. In a hollow space adjacent the closed end of body 2 and handle 3, there is a safety switch 16 Whose actuating button 16:: faces away from handle 3.

A trigger lever 21 is arranged in a forwardly opening recess 22 in handle 3, and a spring 23 biases trigger 21 outwardly of recess 22. The inner edge of trigger 21 is in contact with the actuating button 17a of an actuating switch 17. In order to close switch 17, trigger 21 must be pushed, against the force of spring 23, and opposite to the driving direction of the device.

Two insulated recesses 25 and 26, for accommodation of the terminals of potential or current source 15, are located in the outer end portion of handle 3, and receive respective electric contacts 13a and 14a for conductors 13 and 14. Conductor 14 extends from contact 14a to a terminal 12 at cartridge chamber 10, while the other conductor 13 extends from terminal 13a, through actuating switch 17 and safety switch means 16, to terminal 4 11 at cartridge chamber 10. A detachable closing plate 27, located at the rear ends of body 2 and handle 3, enables installation and exchange of the conductors.

Within the housing formed by hollow body 2, there is located a guide portion whose outer portion 28 is formed with an annular recess 29 facing rearwardly. A spring 30 has one end engaged in recess 29 and its other end engaged in recess 4 of body 2. A pin guide 31 is engaged in portion 28, and has a flange 31a engaging the forward end of portion 28. Pin guide 31 extends axially only over about half the length of portion 28. Its forward end has a recessed bore 32 for accommodating a fastening means, and a recess bore 33 at the rear end of element 31 receives one end of a spring 35 whose other end is engaged with stroke piston 34 and biases the stroke piston back .to the starting position.

Stroke piston 34 comprises two portions, a smaller diameter shaft 34a which is slidably engaged in guide 31 and a larger diameter shaft 34b which is slidably engaged in the outer portion 28 of the guide portion. The forward end of shaft 34a of piston 34 is formed with a bore 36 serving as a guide for the head portion of the fastening means. Cartridge chamber 10 is located in portion 34b of piston 34, at the rear end of the piston. Electrical connection of the terminals or contacts of an electrically detonatable cartridge, placed in cartridge chamber 10, with the terminals 11 and 12 at the cartridge chamber is possible only by pressing the guide portion rearwardly against the bias of spring 30.

During such rearward pressure, actuating button of safety switch means 16 is depressed. By then pressing trigger 21, the detonating circuit is closed by actuating switch 17. Exchanging of cartridges can be effected by opening of a known bayonet lock (not shown) whereupon the guide portion may be removed from housing 2.

Referring to the schematic wiring diagram shown in FIG. 2, cartridge 37 is connected to potential source 15 through terminal 12 and conductor 14, as well as through terminal 11, safety switch means 16, actuating switch 17, and conductor 13.

FIG. 3 is a partial longitudinal sectional view, illustrating the rear portion of a preferred embodiment of the invention device in a position in which it is pressed against the receiving material. This portion contains the parts essential to the invention. The front portion, which is not illustrated, is constructed in a known manner and preferably so that'the device may be opened by turning and raising the front portion.

The device shown in FIG. 3 comprises a metallic housing 40 including portions 40a, 40b and 40c. A metal handle portion 60 is located at the rear end portion of housing 40, and a metal guide portion 41 is arranged axially displaceably within portion 40a of the housing. Guide portion 41 is preferably constructed in a known manner to accommodate a piston, which has not been shown. The rear or inner end portion of guide portion 41 is formed with a conical cartridge chamber 10, accommodating an electrically detonatable cartridge 37, preferably having a plastic case and including electric contacts 38 and 39. The area of housing portion 40c adjacent terminal 39 constitutes the terminal 12 located at the cartridge chamber, and the other terminal 11, cooperating with terminal 38 of the cartridge, is formed by a contact pin 13 which is embedded in insulating material 42 and thus insulated from housing 40.

The rearward part of portion 400 of housing 40 is reduced in diameter to define a recess 44a seating a spring 44 whose rearward end is engaged with a ring 43 projecting inwardly from housing portion 4017, the portion 400 further having a pin 70 projecting rearwardly therefrom and formed with a notch 71. The setting device has to be pressed against the receiving material sufficiently to overcome the bias of spring 44 in order to bring contact pin 13 into electrical contact with a terminal 45, thus closing safety switch means 16. Contact 45 is connected to one terminal of a battery 18 located directly at bracket 60a of the handle portion. The other terminal 46 of battery 18 is in contact with bracket 60a of the handle portion and thus metallically connected electrically to terminal 39 of portion 400 adjacent the cartridge.

Safety switch means 16 is complemented by a pivot lever 49 which is pivoted on a pin 50 and serves as an additional safety element. Pivot lever 49 comprises two arms, arm 49a and arm 49b. Arm 49a extends forwardly and comprises, at its outer end portion, a projection 72 for engagement in recess 71 of projection 70 of portion 400, recess 71 being arranged immediately inwardly of projection 72. Arm 49b extends rearwardly and rests against a trigger 47 which is pivotal about pin 48.

If, as shown in FIG. 3, the setting device is pressed against a receiving material, actuating trigger 47 will press arm 49b of pivot lever 49 upwardly, and arm 49a will thus be pressed downwardly or inwardly. Since the projection 72 of arm 49a then engages into recess 71, actuating button 17a of actuating switch 17 is depressed to an extent such that switch 17, and thus the detonating circuit, are closed and cartridge 37 is detonated. If the setting device is not pressed firmly against the receiving material, projection 72 will not be aligned with recess 71, but will be opposite the portion of the pin 70 which is rearwardly beyond recess 71. Thus, arm 49a will be prevented from being pressed downwardly sufiiciently to close the circuit by actuating switch 17. The actuation of pivot lever 49 requires that the force of a spring 51 be overcome. The portion 49, including the terminals 45 and 46 as well as actuating switch 17, further comprises means for transforming the voltage, such as shown in FIG. 5. Battery 18 is exchangeably connected, by means of plugs 52, to portion 19. The handle portion is defined by a handle 60b which is secured in place by screws 61 and 62.

Referring to FIG. 4, which is a schematic diagram of the electrical circuitry of the device shown in FIG. 3, battery 18 which, for example, may be a 12 volt battery, is electrically connected to box 19 containing the components required for transforming the voltage. A condenser 20, through conductors 13 and 14 and actuating switch 17, is connected to the box 19. The cartridge chamber terminals 11 and 12, together with cartridge 37 and safety switch means 16, is arranged in parallel with condenser 20. Wit-h the position of actuating switch 17 shown in FIG. 4, condenser 20 is, for example, at a voltage of 120 volts as provided from a transformer. After closure of safety switch 16 and operation of actuating switch 17 into its other position, the thus charged condenser is discharged across cartridge 37 and thus detonates the cartridge. In the particular example illustrated, the recharging time for condenser 20 is 8 seconds, which is sufiiciently fast, since the time required for inserting a new cartridge and a new pin is at least this long.

FIG. illustrates the detailed wiring diagram of the device according to FIG. 3, and includes a transformer 53, switches 54, 55 and 56, and various other components such as a transistor and a diode. Switch 55 is in the battery charging line and is normally open, thus preventing short circuiting of battery 18 due to dirt, water and the like.

Switch is closed when the battery Charging plug is inserted. Switch 56 is connected in parallel with condenser 20 and enables the discharge of condenser 20. By actuating switch 54, condenser 20 is charged when actuating switch 15 is in the illustrated position and discharged when actuating switch '17 is moved to its other position.

What is claimed is:

1. A cartridge-operated setting device for driving fastening means, such as nails, pins nd the like, into hard receiving materials, such as concrete and steel, comprising, in combination, housing means forming a guide portion for the fastening means, a handle portion and a cartridge chamber for electrically detonated cartridges; 3. pair of electrical terminals within said cartridge chamber in insulated relation to each other, for connection to the terminals of an electrically detonated cartridge inserted into said chamber; and electric potential applying circuit connectable to a source of electric potential and including respective conductors connected to said terminals; at least one safety switch means connected in said circuit and closed only when the parts of said device are in position to drive a fastening means; and at least one device actuating switch in said circuit and connected to said safety switch means in a manner such that both said safety switch means and said actuating switch must be closed to actuate said device.

2. A device, as claimed in claim 1, including a detonating potential source physically associated with said device.

3. A device, as claimed in claim 2, in which said detonating potential source includes a battery and means operatively connected to said battery and operable to develop at least a preset detonating potential.

4. A device, as claimed in claim 3, in which said battery is rechargeable.

5. A device, as claimed in claim 3, in which said detonating potential source includes a condenser; said actuating switch having a pair of positions in one of which it closes a condenser charging circuit including said potential source and said condenser and in the other of which it completes an electric circuit including said condenser and said electrical terminals.

6. A device, as claimed in claim 3, in which said housing means is metal and constitutes one of said conductors.

7. A device, as claimed in claim 5, in which said housing means is metal and constitutes one of said conductors.

8. A device, as claimed in claim 1, including interlocking safety means preventing closure of said actuating switch except when the parts of said device are in position to drive a fastening means.

References Cited UNITED STATES PATENTS 2,780,810 2/1957 Catlin et a1 2279 2,931,039 4/1960 Henning et al 227--11 3,150,488 9/1964 Haley 2279 3,361,064 1/1968 Johnston et a1. 1028 BERNARD STICKNEY, Primary Examiner US. Cl. X.R.

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