Chucks or sockets – Socket type – Lost motion
Patent
1995-06-13
1997-12-30
Bishop, Steven C.
Chucks or sockets
Socket type
Lost motion
279 195, 279 97, 403318, 403355, B25D 1708
Patent
active
057021120
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE DISCLOSURE
The present invention relates to a tool locking apparatus for machine hammers of the type having a front head with an impact delivering working tool carried axially movably therein, at least one wedge disposed transversely in the front head and insertable into form-restricted engagement with a side recess in the working tool in order to limit the axial movability of and lock the working tool relative to the front head, and a key axially insertable transversely into the front head to extend across the the wedge and retain the wedge in a position locking the working tool.
In this predominantly heavy type of machinery, the demands concerning safe locking of the working tool in the machine housing are very high. A tool which falls out, for instance when penetrating a concrete vault, can cause considerable material damage, and above all, can lead to serious personal injury. In larger mostly hydraulically driven types of machine hammers, it is not unusual that the weight of the working tool reaches 130 kg, which underlines the danger. Simultaneously there is also the demand that changes between different types of tools, for example breaking tools, chisels, spades and rams, under active field service conditions can be made as quickly as possible.
In earlier constructions applicant has himself made use of spring loaded pins for locking the wedges. Wear study indicates, that impact waves during work of the machine hammer via the wedges are transmitted to the pins, tend to urge them into an oblique position due to their short guiding length, and lead to increased wear. Worn wedges and damaged pins can be replaced by exchange, while wear of the machine housing affects a main component which cannot be looked at as a spare part. Furthermore, there is the risk of broken springs endangering safe locking of the wedges. An alternative earlier suggestion known to applicant, which consisted in locking the wedges by engagement with spring loaded sleeves, was in the long run similarly liable to wear and fatigue of the springs.
In the type of machine hammers stated by way of introduction above, and in particular concerning heavy, preferably hydraulically driven machines to be mounted on booms of mobile working machinery, the object of the present invention is to create a locking means able to offer increased safety against the tool falling out from the machine during operation, and to allow easier handling when changing the tool under field conditions. These objects are achieved by the apparatus defined in the claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail hereinafter with reference to the accompanying drawing. FIG. 1 of the drawing shows a partial longitudinal section through the forward portion of a machine hammer embodying the invention. FIG. 2 shows a cross section on the line 2--2 in FIG. 1. FIG. 3 is a side view of the front head viewed in the direction of arrows 3--3 in FIG. 1.
DETAILED DESCRIPTION
The machine hammer 10 in FIG. 1 carries a front head 11 in which a working tool 12, for example a breaking tool, is axially movably guided in a tool sleeve 13, suitably made of steel and strongly press fitted in the front head 11. When starting the machine, the movability of the working tool 12 is supported by lubricating grease, portion-wise supplied via ring grooves and lubricating passages 15, 17 to the interior of the tool sleeve 13. In a conventional way, not illustrated in FIG. 1, a suitably hydraulically driven reciprocating hammer piston 14 delivers impact energy to the working tool 12. Diametrically opposed side recesses 16 are provided in the working tool 12 and wedges 18, carried in the front head 11, extend transversely to the working tool 12 into the recesses 16 which by form-bound engagement at their opposite ends are adapted to limit the axial movement of the working tool 12, thereby retaining the tool 12 in the front head 11 and hindering it from falling out. In the present instance the wedges 18, as usual in case of h
REFERENCES:
patent: 1049984 (1913-01-01), Bowers
patent: 2279960 (1942-04-01), Terry
patent: 2935327 (1960-05-01), Lear
patent: 3997989 (1976-12-01), Stepe
patent: 4096653 (1978-06-01), Kaarlela et al.
Derwent Abstract, No. 91-236082/32, week 9132, Abstract of SU 1592482 (AS Sibe Mining Inst), 15 Sep. 1990.
Brannstrom Osten Kurt
Fredin Stig Bertil Artur
Atlas Copco Berema Aktiebolag
Bishop Steven C.
LandOfFree
Tool locking apparatus for machine hammers does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tool locking apparatus for machine hammers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tool locking apparatus for machine hammers will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-196028