AU8932301A - Fastener setting device with power control - Google Patents

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Hilti Aktiengesellschaft Actual Inventor: Harald Fielitz Address for Service: BALDWIN SHELSTON WATERS S 60 MARGARET STREET SYDNEY NSW 2000 CCN: 3710000352 Invention Title: 'FASTENER SETTING DEVICE WITH POWER CONTROL' The following statement is a full description of this invention, including the best method of performing it known to me/us:- File: 32701AUP00 -1A- BACKGROUND OF THE INVENTION The invention relates to a fastener setting device for power-regulated driving of nail-shaped fastening elements into hard bases such as, for example, concrete, rock, or steel.

DE19755730 discloses a fastener setting device driven by combustion of a gasair mixture and comprised of a housing, a guide cylinder, an axially displaceable drive piston, a fastening element guide arranged on the setting direction side of the guide cylinder, and an axially displaceable contact sleeve, the sleeve surrounding the fastening element guide and axially displaceable against the force of several springs. Within the guide cylinder a hollow-cylindrical elastic damping element is arranged surrounding a shank of the drive piston, the damping element cushioning the drive piston at the end of the driving-in operation.

Fastener setting devices are used to fasten different materials to diverse structural components. When doing so, the energy required by the device for driving the nail must be within certain limits in order to assure that on the one hand there is sufficient anchoring of the fastener in the structural component and, on the other hand, perforation of the component by the nail is safely avoided. This problem is made even more acute S by the fact that, for example in the case of fastening wood to hard concrete, even in soft concrete, the goal is to have only a few millimeters of the nail still protruding.

According to DE 1911008, a radially moveable, spring-biased, externally manually operated pawl member is provided, whose rotating head member is used for adjustment of the combustion chamber in order to effect power changes in the fastener -2setting device by alteration of the size of the combustion chamber, wherein the essentially pin-shaped pawl member engages in the combustion chamber. According to U.S. 5,029,755, the drive piston forms a stop ring. The disadvantage in the aforesaid solutions for changing the combustion chamber, along with the limitation to powder charge operated fastener setting devices, resides particularly in the contamination of the control mechanism and thus diminished reliability.

Power control can be achieved in that energy can be reduced, if required, in the case of a fastener setting device that is designed for relatively high power output. By using an axially displaceable contact sleeve the lead of the drive piston can be changed; that is, when a certain drive depth is reached the drive piston travels into an elastic i "buffer over which the excess energy is spent. However, the bolt setting device must be oo.

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partly dismantled for changing the contact sleeve or adjustment of its length.

According to EP0962289 the power change using damping of the drive piston of •a fastener setting device is adjustable using springs biasing the elastic damping element.

%0.0 The change of the spring-bias is, however, possible only using special tools.

SUMMARY OF THE INVENTION 0 a.

The object of the invention is the provision of a power control device for a fastener setting device that can be directly effected manually and is reliable.

Essentially, a fastener setting device comprises a guide cylinder arranged in a housing, the guide cylinder having an axially displaceable drive piston, a guide abutting the setting direction side of the guide cylinder, a contact sleeve that surrounds the guide -3externally at least partly and which on contact with the work-piece is axially displaceable against the force of a spring with respect to the housing and the guide cylinder opposite to the setting direction, and a hollow-cylindrical elastic damping element surrounding a shank of the drive piston arranged within the guide cylinder, wherein the contact sleeve is formed of an inner sleeve and an outer sleeve, the outer sleeve partially enclosing the inner sleeve, and the sleeves being displaceably fixably alignable relative to each other in at least two different axial end positions.

By the directly manually effected axial elongation of the contact sleeve, the drive piston is urged into the damping element at differing setting depths and, as a result, spends a corresponding portion of the total available energy on the damping element or, S conversely, on the fastener, whereby the result is a control of power.

ee Advantageously, force transmission webs of the inner sleeve and force transmission grooves of the outer sleeve extend, at the part of the outer surface of the •inner sleeve covered by the outer sleeve and the inner surface of the outer sleeve, and interlocking only at a particular angle of inner and outer sleeves, radially •circumferentially over one part of the circumference for the purpose of absorption of the high axial forces effected at the time of the setting process. In addition, the sleeves provide for guidance with bayonet-like rotary-interlocking fixing of the inner sleeve with the outer sleeve by a small rotational angle on the order of magnitude of 300.

Further advantageously, at the part of the outer sleeve covering the inner sleeve, the outer sleeve has a detent bore through which a detent pin passes, the pin engaging the inner sleeve in radial detent recesses of its outer surface.

-4- Again advantageously, the detent pin is biased radially inwardly by way of a spring member fastened at the outer sleeve.

Still advantageously, the inner sleeve has, at the part of the outer surface of the inner sleeve covered by the outer sleeve, a radial guide member with circumferentially extending transversely and axially longitudinally oriented curve segments that are arranged for guiding the detent pins and thus for permissive offsetting movement of the outer sleeve relative to the inner sleeve for positioning in at least two different axial end positions.

The radial guide member of the inner sleeve advantageously exhibits a radially elevated part and thus an initial segment accessible only by overcoming a certain resistance, which is formed axially up to and including a face or a flange associated with "the outer sleeve and consequently facilitates easy dismantling of the outer sleeve. This is advantageous, for example, in the case of jamming of the fastening setting device, for cleaning purposes and for replacement with other, special outer sleeves.

Further advantageously, the guide and the inner sleeve and/or the outer sleeve are open on one side, whereby fastening elements are automatically introduced S"consecutively into the guide from a laterally arranged magazine.

BRIEF DESCRIPTION OF THE INVENTION The invention is more fully explained by reference to an illustrative example and read together with: Fig. 1 showing an axially extending section view of a fastener setting device; and Fig. 2 is an exploded partial perspective view of the fastener setting device.

DETAILED DESCRIPTION OF THE INVENTION According to Fig. 1 or the detail in the exploded perspective view in Fig. 2, a fastener setting device 1 comprises an axially extending guide cylinder 3 with an axially displaceable drive piston 4 arranged in a housing 2, and a guide 5 abutting one end of the guide cylinder 3 and facing in the setting direction. A hollow-cylindrical elastic damping element 7 surrounding a shank 6 of the drive piston 4 is arranged inside the S 10 guide cylinder 3. A contact sleeve 8, arranged externally of and axially surrounding the i• guide 5 and being axially displaceable and is made up of an inner sleeve 9 and an outer sleeve 10, with the outer sleeve coaxially with and partly surrounding the inner sleeve, which sleeves are displaceable relative to each other in a rotary-locking fashion by rotation and axial displacement in the manner of a bayonet into two different end positions 1 la, 1 lb. The guide 5, the inner sleeve 9 and the outer sleeve 10 are open in a sector less than 1800 for receiving a fastener magazine (not shown in the figures). A radial detent borehole 12 is arranged through the outer sleeve 10 and into which a detent pin 13 is inserted by a spring element 14, formed as a torsion spring mounted on the outer sleeve 10, the spring element being radially inwardly biased and moveably arranged. The detent pin 13 engages radially into grooved detent recesses 15a, 15b of a radially recessed guide member 16 on the outer surface of the inner sleeve 9, the guide member being constructed as a U-shaped continuous curve for permitting precise positioning in one of the radially deepened detent recesses 15a, 15b, such recesses being -6formed as countersinks, in which the inner sleeve 9 relative to the outer sleeve fixes precisely form-lockingly at one of the adjustable axial end positions 1 la, 1 lb, in that the detent pin 13, upon reaching such position, drops precisely into one of the detent recesses 15a, 15b. The axial compression force is transferred over respective partly circumferentially extending force transfer webs 17 arranged on the inner sleeve 9 and complementary force transfer grooves 18 arranged on the outer sleeve, which are in engagement only within a certain angular range of approximately 300. For removal of the outer sleeve 10, such sleeve is rotatable by a larger angle of rotation, whereby the detent pin guided along the guide member 16 is radially moveable out of the guide member 16 relative to the bias of the spring element 14 and further into a radially slightly elevated insertion section 19. The insertion segment 19 extends axially to a Sflange 20 associated with the inner sleeve 9.

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Claims (8)

1. A fastener setting device for driving a fastener into a hard target material comprising an axially extending guide cylinder having a first end and a second end spaced apart to the axial direction, an axially displaceable drive piston extending into said guide cylinder from the second end thereof toward the first end, axially extending guide for said drive piston abutting the second end of said guide cylinder, a contact sleeve coaxial with and at least partly surrounding said guide, a hollow cylindrical damping element located within the second end of said guide cylinder and surrounding an axially extending shaft of said drive piston, said contact sleeve comprising an axially extending inner sleeve and an axially extending outer sleeve at least partially laterally enclosing said inner sleeve with said contact sleeve located on the opposite side of the second end of said guide cylinder from the first end thereof, said inner and outer sleeves being rotatable and axially displaceable relating to each other into at least two axially S. spaced locked positions. o 15

2. A fastener setting device, as set forth in claim 1, wherein interlocking force transfer webs and force transfer grooves extend circumferentially of and are *•eeo formed in said contact sleeve with said transfer webs formed on an outer surface of said inner sleeve and said transfer grooves formed on an inner surface of said outer sleeve S. and overlapping said inner sleeve and located in a definite angular circumferential direction of said inner and outer sleeves.

3. A fastener setting device, as set forth in claim 2, wherein said outer sleeve in an axially extending part thereof covering the outer surface of said inner sleeve has a radially extending detent borehole therein arranged to receive a detent pin for -8- engagement in radially extending axially spaced detent recesses in the outer surface of said inner sleeve.

4. A fastener setting device, as set forth in claim 3, wherein said detent pin is spring biased radially inwardly by a spring element mounted on said outer sleeve.

5. A fastener setting device, as set forth in claim 3, wherein the outer surface of said inner sleeve within said outer sleeve has a radially outwardly and circumferentially extending guide member for guiding said detent pin between said detent recesses.

6. A fastener setting device, as set forth in claim 5, wherein said guide 10 member on said inner sleeve has an axially extending insertion section with a base spaced radially outwardly from a base of said guide member.

7. A fastener setting device, as set forth in claim 1, wherein said guide and ooooo at least one of said inner sleeve and said outer sleeve are open in a circumferentially and axially extending sector section. ooooo1 -9-

8. A fastener setting device for driving a fastener into a hard target material substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples. DATED this 8 th day of November 2001 HILTI AKTIENGESELLSCHAFT Attorney: CAROLINE M. BOMMER Fellow Institute of Patent and Trade Mark Attorneys of Australia of BALDWIN SHELSTON WATERS