Plastic article or earthenware shaping or treating: apparatus – Preform assembly means and means for bonding of plural... – Means press fitting or forcibly embedding one preform into...
Reexamination Certificate
1999-07-14
2001-05-22
Pyon, Harold (Department: 1722)
Plastic article or earthenware shaping or treating: apparatus
Preform assembly means and means for bonding of plural...
Means press fitting or forcibly embedding one preform into...
C029S434000, C029S527100, C249S058000, C249S098000, C264S238000
Reexamination Certificate
active
06234782
ABSTRACT:
TECHNICAL FIELD
The invention relates to an injection mould for making a bucket with a handle being pivotally connected to the bucket at two diametrically opposed portions thereof, each end of the handle being provided with a radial projection facing inwards and having an enlarged head snap-engaging an opening in an ear formed on the exterior of the bucket in each of the said diametrically opposed portions, said injection mould comprising a stationary mould half and a movable mould half axially displaceable in relation to each other between a closed and an open position and defining a handle mould cavity corresponding to the shape of the handle and a bucket mould cavity corresponding to the shape of the bucket, the stationary mould half having a female mould part to form the outer surface of the bucket and the movable mould half having a male mould part to form inner surface of the bucket.
BACKGROUND ART
The most common method of manufacture of a plastic bucket with a handle is to mould the bucket and the handle in individual moulds and subsequently mounting the handle on the bucket by bringing the projections of the handle into snap engagement with the openings in the ears of the bucket.
Several attempts have been made to manufacture a plastic bucket with an associated handle in an one piece mould. The previously suggested moulds are, however, rather complicated and considerably larger than a conventional mould for the separate manufacture of a bucket. The use of a larger mould entails that a larger injection press is needed to manufacture the bucket resulting in increased manufacturing costs.
U.S. Pat. No. 4,632,357 discloses a mould for making a bucket with a handle, the bucket and handle being moulded with the projections of the handle engaging openings in the ear of the bucket. Furthermore U.S. Pat. No. 4,210,620 discloses a mould for making a pail with a bail, each opposing end of the bail provided with an opening interengaging corresponding projections on the exterior of the bucket. The projections and the ears are moulded in interengagement. Both of the moulds suggested in the two publications are fairly large and complicated.
BRIEF DESCRIPTION OF THE INVENTION
the object of the invention is to provide an injection mould for making a bucket with a handle and whose design is more simple than known moulds and which is substantially not larger than a conventional mould used for making a separate bucket.
The injection mould according to the invention is characterised in that the handle mould cavity in its entirety is radially external to the bucket mould cavity, the mould portion forming the projections of the handle being in the same axial plane as the mould portions forming openings of the bucket, but axially displaced towards the movable mould half, and in that the movable mould half comprises an ejection plate having ejection pins extending to the handle mould cavity, and that in the portion corresponding to each of the projections the handle mould cavity being externally defined by a movable mould member arranged on an arm connected to the ejection plate, a driving means being attached to the arm and adapted to drive the mould member with the handle inwardly so as to bring the projections of the handle into engagement with the openings of the bucket ears when the ejection movement of the ejection plate is completed.
The handle and the bucket are thus moulded simultaneously in separate cavities. When opening the mould the handle and the bucket are both in the movable mould half. The handle is then ejected, while the bucket remains on the male mould part of the movable mould half. During the ejection of the handle the movable mould members are moved axially outwardly synchronously with the handle due to their connection with the ejection plate through the arms. Then the mould members and thus also the handle portions with the projections are driven substantially radially inwardly so as to bring the projections into engagement with the openings in the ears of the bucket. Finally the bucket with the handle mounted thereon is removed from the movable mould half. The injection mould according to the invention corresponds in many ways to a conventional mould for making a separate bucket, the present mould, however, further being provided with the handle mould cavity and the ejection plate with the associated ejection pins and with the movable mould members with the associated arms and driving means. This further entails that the present invention can be used for converting existing moulds used for making a separate bucket and that the present mould is not larger that a mould for making the separate bucket, for which reason larger machines are not required for making a bucket with a handle in a mould according to the present invention than hitherto have been used for making the bucket. Furthermore, due the fairly simple structure of the mould, the cycle time is substantially the same as the cycle time when making a separate bucket, whereby a saving in time is obtained in relation to the conventional method, in which the handle and the bucket are made in separate moulds and the handle subsequently is mounted on the bucket.
According to the invention the movable mould members may each have a mould cavity forming portion adapted to ensure a releasable attachment of the handle to the mould members when the said members are driven inwardly to bring the projections of the handle into engagement with the openings of the bucket ears. As a result the handle is securely retained when it is removed from the handle mould cavity and its projections subsequently are brought into engagement with the openings of the bucket ears. In this connection it should be noted that the force necessary to remove the mould cavity forming portions of the movable mould members from the handle of course is less than the force necessary for pulling the projections of the handle out of snap engagement with the openings of the bucket ears when these interengage said openings.
Furthermore according to the invention the mould cavity forming comprises a recess provided in the movable mould member and forming a portion of a rib externally on the handle. Since conventional handles often are provided with an outer rib to increase the rigidity of the handle, this embodiment presents no substantial change in the appearance of a conventional handle.
Moreover according to the invention the mould member may be fixedly secured to the arm which in turn is connected to the ejection plate such that at least the portion of the arm on which the mould member is arranged may be driven inwardly.
In this connection, according to yet another embodiment of the invention the arm may be pivotally connected to the ejection plate. This embodiment of the invention is currently considered to be the most advantageous embodiment.
Furthermore according to the invention the driving means may comprise a slide arranged radially displaceably in the movable mould half, said slide having an opening through which the arm extends, and said opening being provided with guide surfaces radially on each side of the arm so as to ensure that the movable mould member is displaced substantially axis parallel to the guide pins during the ejection movement of the ejection plate.
Finally according to the invention the movable mould member or the arm on which this is arranged and the stationary mould half may have abutment faces co-acting in radial direction and abutting each other in the closed position of the mould so as to prevent the injection pressure, to which the movable mould member is subjected, from being transferred to the driving means.
REFERENCES:
patent: 3358877 (1967-12-01), Eckhoff
patent: 3631584 (1972-01-01), Walkup et al.
patent: 3861840 (1975-01-01), Heisler
patent: 4210620 (1980-07-01), Von Holdt
patent: 4632357 (1986-12-01), Von Holdt
patent: 4796775 (1989-01-01), Dudzik
patent: 4799306 (1989-01-01), Collins et al.
patent: 4896415 (1990-01-01), Bock
patent: 3345216 (1984-06-01), None
patent: WO9406694 (1994-03-01), None
A.B.C. Hansen Vaerktojsfabrik A/S
Luk Emmanuel
Pillsbury Winthrop LP
Pyon Harold
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