Tool driving or impacting – Impacting devices – With impact cushioning means
Patent
1998-06-22
2000-05-30
Vo, Peter
Tool driving or impacting
Impacting devices
With impact cushioning means
173 935, 1731621, 173211, B25D 1500
Patent
active
060680679
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a tool, in particular a power screw driver, comprising an output shaft which is rotatably mounted in a housing and is driven by a motor and which extends substantially coaxially to a longitudinal axis of the housing.
Such a tool is, for instance, known from DE 3503032 C2 or G 8310596. DE 3503032 C2 discloses a pneumatically operated power screw driver in which the substantially cylindrical housing simultaneously serves to hold the tool. The output shaft which is driven by a compressed-air motor projects from the housing and serves to transmit impacts to screws, nuts, or the like, which are to be tightened or unscrewed.
G 8310596 discloses a portable device for burring edges of drilled holes with very limited access possibilities. The corresponding housing simultaneously serves as a grip tube for the tool. An associated motor is accommodated in the housing and drives a shaft having an end that projects from the housing and has arranged thereat a tool head for removing burs.
In the two prior-art tools and, in particular, in the power screw driver, vibrations and impacts are observed in the entire tool. These vibrations or impacts are transmitted via the housing, which simultaneously serves as a grip member, to a user's hand. As a consequence, the hand and, in particular, the wrist are strained considerably. Such strain is intensified by the fact that because of the vibrations the user must firmly grip the tool in order to hold the tool in an accurate position.
It is therefore the object of the present invention to improve a tool of the type described in such a manner that the tool can be held comfortably, in controlled manner and with little force.
In connection with the features of the preamble of claim 1, this object is achieved by the measure that a grip sleeve which is rotatable relative to the housing is fitted over the housing, and at least one damping device that counteracts a pulse-like rotation of the grip sleeve relative to the housing is disposed between the housing and the grip sleeve.
Rotation of the grip sleeve relative to the housing is only observed in the case of impacts which are transmitted by tool vibrations or the like in pulse-like fashion to the grip sleeve. Such an impact and the associated pulse-like rotation of the grip sleeve relative to the housing are suppressed or at least attenuated by the damping device counteracting said rotation.
Such a damping device may be designed in the form of a shock absorber and may, for instance, function pneumatically or hydraulically.
In a preferred embodiment, the damping device is of a mechanical type and comprises at least one compression spring fixed between housing and grip sleeve. In such a case, the grip sleeve is only connected via the compression spring in non-rotatable fashion to the tool proper via the housing. The spring fully receives the developing starting torque of the motor and dampens the tool vibrations or impacts transmitted in pulse-like fashion to the grip sleeve.
To fix the compression spring relative to the housing and the grip sleeve in a simple manner, each of the damping devices comprises two abutment bodies which are acted upon by ends of the compression spring and which are arranged one after the other in the circumferential direction of housing and grip sleeve and are each in contact with the two members. As a result, the starting torque, the tool vibrations or other impacts are transmitted to the compression spring via the abutment bodies which are in contact with the housing, whereby said spring is tensed and exerts a restoring force in a direction opposite to the relative rotation between housing and grip sleeve, whereby said rotation is attenuated. This takes place in an analogous manner for the two possible rotational directions.
For an easy support of the damping device, the device is disposed between an annular flange which projects substantially radially from the housing, and an annular chamber which is formed at a first end of the grip sleeve and is open towards the annular fla
REFERENCES:
patent: 2184394 (1939-12-01), Moretti
patent: 2662434 (1953-12-01), Burkhardt
patent: 2907239 (1959-10-01), Schwenk
patent: 3952545 (1976-04-01), Koeslin
patent: 4036085 (1977-07-01), Sjostrand et al.
patent: 4140446 (1979-02-01), Fernstrom et al.
patent: 4243129 (1981-01-01), Schoeps
patent: 4341475 (1982-07-01), Saladin
patent: 4691786 (1987-09-01), Fujita et al.
patent: 4875528 (1989-10-01), Thackston
patent: 4950110 (1990-08-01), Suzuki
patent: 5080180 (1992-01-01), Hansson
patent: 5706902 (1998-01-01), Eisenhardt
Calve James
Cooper Power Tools GmbH & Co.
Vo Peter
LandOfFree
Power screw driver with damping device between covered grip and does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Power screw driver with damping device between covered grip and , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power screw driver with damping device between covered grip and will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1904006