U.S. patent application number 12/514136 was filed with the patent office on 2009-09-17 for crimping of detonators.
This patent application is currently assigned to AFRICAN EXPLOSIVES LIMITED. Invention is credited to Horst Wolfgang Friedrich Von Lengeling.
Application Number | 20090229338 12/514136 |
Document ID | / |
Family ID | 38984445 |
Filed Date | 2009-09-17 |
United States Patent
Application |
20090229338 |
Kind Code |
A1 |
Von Lengeling; Horst Wolfgang
Friedrich |
September 17, 2009 |
CRIMPING OF DETONATORS
Abstract
A device for crimping the mouth of a detonator housing comprises
a pair of opposed jaws reciprocally movable relative to each other,
and a plurality of toothed segments on each jaw. The segments are
moveable, are located in a jaw cavity, and together form a
segmented ring. The side faces of each segment converge from a
broad radially outer end towards a toothed radially inner narrow
end. A resiliently stressable biasing element is provided between
each adjacent pair of segments. The biasing elements act to space
the segments of each pair apart when the jaws are spaced apart from
each other, and also act to permit the segments, in response to
movement of the moveable segments arising from the closing of the
jaws, to abut against one another in series when the jaws are
tightly in contact with each another, to form the segmented
ring.
Inventors: |
Von Lengeling; Horst Wolfgang
Friedrich; (Pretoria, ZA) |
Correspondence
Address: |
SHERIDAN ROSS PC
1560 BROADWAY, SUITE 1200
DENVER
CO
80202
US
|
Assignee: |
AFRICAN EXPLOSIVES LIMITED
Woodmead
ZA
|
Family ID: |
38984445 |
Appl. No.: |
12/514136 |
Filed: |
November 8, 2007 |
PCT Filed: |
November 8, 2007 |
PCT NO: |
PCT/IB2007/054539 |
371 Date: |
May 8, 2009 |
Current U.S.
Class: |
72/402 ;
86/1.1 |
Current CPC
Class: |
F42B 3/195 20130101 |
Class at
Publication: |
72/402 ;
86/1.1 |
International
Class: |
B21D 39/04 20060101
B21D039/04; F42B 3/195 20060101 F42B003/195 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 2006 |
ZA |
2006/09332 |
Claims
1. A device for crimping the mouth of a metal detonator housing
around an initiating element protruding into the housing through
the mouth, the device comprising a pair of opposed jaws, at least
one which is movable relative to the other and is reciprocally
mounted so that at least one of the jaws is reciprocally movable
alternately towards and away from the other jaw to successively
bring the jaws tightly into contact with each other and then to
space the jaws apart from each other each jaw being provided with
three toothed segments arranged side-by-side in series on each jaw,
all of the segments being movable and being in the form of movable
inserts located in a single cavity provided in each jaw for
receiving the inserts, each segment having a pair of side faces
whereby the segment abuts an adjacent segment when the jaws are
tightly in contact with each other so that the segments of the jaws
together form a segmented ring, the side faces of each segment
converging from a broad radially outer end of the segment towards a
toothed radially inner narrow end of the segment, each segment
thereby having a tapering shape when viewed in a direction parallel
to the axis of the ring, with the teeth of each segment being
parallel to said axis; a resiliently stressable biasing element
provided between each adjacent pair of segments in a jaw, the
biasing element acting to space the segments of the pair apart when
the jaws are spaced apart from each other and acting to permit the
segments, in response to movement of the moveable segments arising
from the closing of the jaws, to abut against one another in series
when the jaws are tightly in contact with each another, to form the
segmented ring, the ring defining, at its centre, a passage having
a toothed cross-sectional outline provided by the toothed narrow
ends of the segments for holding a crimped mouth of a detonator,
the mouth having been crimped by the toothed inner ends of the
segments in response to radially inward movement of the segments
caused by the tight closing of the jaws.
2. The device according to claim 1, wherein each cavity provides
one or more abutment faces for abutting respectively against the
broad ends of the movable segments.
3. The device according to claim 2, wherein the abutment faces are
flat and wherein the broad ends of the movable segments have
radially outwardly facing surfaces which are also flat.
4. The device according to claim 2, wherein a radial projection
projects radially outwardly from the outer surface of the broad end
of the segment into a tangential slot provided in the associated
abutment face of the cavity.
5. The device according to claim 1, wherein each biasing element is
an elastomeric block which is held captive in a cavity in the side
face of one of the segments of the pair of segments between which
it acts.
6. The device according to claim 5, wherein each elastomeric block
projects tangentially outwardly from its cavity relative to the
axis of the ring when the jaws are spaced apart from each other,
thereby acting to space apart the segments of the pair, and is
compressed and forced into its associated cavity by the side face
of the other segment of the pair when the jaws are tightly in
contact with each other.
7. The device according to claim 5, wherein each elastomeric block
is cylindrical in shape, being located in a correspondingly
part-cylindrical cavity having an axis which is parallel to the
axis of the ring.
8. The device according to claim 1, wherein each jaw comprises an
elongated rectangular flattened bar, the bar being longer than it
is wide and wider than it is thick so that it has a pair of major
faces spanning the length and width of the bar; a pair of side edge
faces spanning the length and thickness of the bar; and a pair of
end edge faces spanning the width and thickness of the bar, the
bars abutting against each other by means of a pair of opposed side
edge faces thereof, when the jaws are in the tightly closed
condition.
9. The device according to claim 8, wherein the cavities holding
the respective series of segments are semi-regular-polygonal
indentations in the respective opposed side edge faces of the bars
and extend from one major face of the bar to the other.
10. The device according to claim 9, wherein the axes of the
semi-regular-polygonal indentations are parallel to the axis of the
ring.
11. The device according to claim 8, wherein a cover plate encloses
the major face of each bar and acts to hold the segments and
biasing elements in place against axial movement thereof in a
direction parallel to the direction of the ring axis.
12. The device according to claim 11, which includes a guide pin
protruding from each of the segments, with a complementary guide
slot in which each of the guide pins is movingly located, being
provided in the cover plate.
13. The device according to claim 8, wherein the jaws are provided
respectively on their side edge faces which abut when the jaws are
tightly in abutment, with a guide pin and an opposed tubular guide
socket, the pin entering the socket when the jaws approach each
other and leaving the socket when the spacing between the jaws is
increased sufficiently, as the jaws leave each other.
Description
[0001] THIS INVENTION relates, broadly, to the crimping of
detonators for detonating explosives. More specifically, the
invention relates to a device and a method for crimping the mouth
of a metal detonator housing around an initiating element such as a
shock-tube, fuse or electrical lead protruding into the
housing.
[0002] According to the invention, there is provided a device for
crimping the mouth of a metal detonator housing around an
initiating element protruding into the housing through the mouth,
the device comprising [0003] a pair of opposed jaws, at least one
which is movable relative to the other and is reciprocally mounted
so that at least one of the jaws is reciprocally movable
alternately towards and away from the other jaw to successively
bring the jaws tightly into contact with each other and then to
space the jaws apart from each other; [0004] a plurality of toothed
segments arranged side-by-side in series on each jaw, at least some
of the segments being moveable and at least some of the segments of
each jaw being located in one or more cavities provided therefor in
the jaw, each segment having a pair of side faces whereby the
segment abuts an adjacent segment when the jaws are tightly in
contact with each other so that the segments of the jaws together
form a segmented ring, the side faces of each segment converging
from a broad radially outer end of the segment towards a toothed
radially inner narrow end of the segment, each segment thereby
having a tapering shape when viewed in a direction parallel to the
axis of the ring, with the teeth of each segment being parallel to
said axis; [0005] a resiliently stressable biasing element provided
between each adjacent pair of segments in a jaw, the biasing
element acting to space the segments of the pair apart when the
jaws are spaced apart from each other and acting to permit the
segments, in response to movement of the moveable segments arising
from the closing of the jaws, to abut against one another in series
when the jaws are tightly in contact with each another, to form the
segmented ring, the ring defining, at its centre, a passage having
a toothed cross-sectional outline provided by the toothed narrow
ends of the segments for holding a crimped mouth of a detonator,
the mouth having been crimped by the toothed inner ends of the
segments in response to radially inward movement of the segments
caused by the tight closing of the jaws.
[0006] Each jaw may have the same number of segments. The number of
segments in each jaw may be selected by routine experimentation,
bearing in mind difficulties in obtaining a desirably circular
toothed passage when the jaws are tightly closed, when there are
too few segments, and difficulties associated with expense and
complexity of construction, when there are too many segments.
[0007] The number of segments in each jaw may thus be in the range
of 2 to 8, more preferably 3 to 5, and conveniently 3.
[0008] More particularly, each jaw may have an odd number of
segments, for example 3, 5 or 7, the preferred number again being
3, so that there are, in each jaw, a central segment and one or
more additional segments on each side of the central segment.
[0009] At least one segment in each jaw, for example the central
segment, may be fixed and hence immovably connected or integral
with the remainder of its associated jaw, with a cavity being
provided in the jaw on each side of the fixed segment for receiving
one or more movable segments.
[0010] Alternatively, all of the segments may be movable, being in
the nature of movable inserts, a single cavity being provided in
each jaw for receiving the inserts, in which cavity the inserts are
located.
[0011] Each cavity may provide one or more abutment faces for
abutting respectively against the broad ends of the movable
segments. The abutment faces may be flat and the broad ends of the
movable segments may have radially outwardly facing surfaces which
are also flat. Each abutment face and the radially outer surface of
the associated segment may be provided with a radial projection
which projects into an associated tangential slot, relative to the
ring. The projection may be a radially outward projection from the
outer surface of the broad end of the segment and the tangential
slot may be provided in the abutment face of the recess, or in
principle vice versa, with the projection projecting radially
inwardly from the abutment face of the recess and the tangential
slot being provided in the outer surface of the broad end of the
segment.
[0012] When there is an odd number of segments in each jaw,
however, there need be no slot and projection acting between the
outer surface of the broad end of the central segment and the
associated abutment face, the abutment face and outer surface of
the central segment instead respectively being provided with
opposed sockets, and a biasing member such as a coil spring under
axial compression or an elastomeric block under similar axial
compression, being located in the opposed sockets and spanning the
interface between the outer surface of the broad end of the central
segment and the abutment face, the compression of the biasing
member acting to urge the outer face of the central segment away
from the associated abutment face.
[0013] Each biasing element may be an elastomeric block which is
held captive in a cavity provided therefor in the side face of one
of the segments of the pair of segments between which it acts. The
elastomeric block may project tangentially outwardly from its
cavity relative to the axis of the ring, when the jaws are spaced
apart from each other, the block thereby acting to space apart the
segments of the pair, and is compressed and forced into its
associated cavity by the side face of the other segment of the pair
when the jaws are tightly in contact with each other. Each
elastomeric block may be cylindrical in shape, being located in a
correspondingly part-cylindrical cavity having an axis which is
parallel to the axis of the ring.
[0014] Each jaw may comprise a more or less elongated rectangular
flattened bar, conveniently of metal, the bar being longer than it
is wide and wider than it is thick, so that it has a pair of major
faces spanning its length and width, a pair of side edge faces
spanning its length and thickness, and a pair of end edge faces
spanning its width and thickness, the bars abutting against each
other, by means of a pair of opposed side edge faces thereof, when
the jaws are in the tightly closed condition. In this case the
cavities holding the respective series of segments may be more or
less semi-regular-polygonal indentations into the respective
opposed side edge faces of the bars, the indentations extending
from one major face of the bar to the other. The axes of the
polygons may be parallel to the axis of the ring, and each cavity
may in turn also extend from one major face of the bar to the
other. Each major face of each bar may be enclosed by a cover
plate, which acts to hold the segments and biasing elements in
place against axial movement thereof in the direction of the ring
axis.
[0015] The device may include a guide pin protruding from at least
one of the segments, into a complementary guide slot in the cover
plate which abuts that segment. Typically, each of the segments may
be provided with such a guide pin, with each guide pin then located
in its own complementary guide slot.
[0016] The jaws may further be provided respectively on their side
edge faces which abut when the jaws are tightly in abutment, with a
guide pin and an opposed tubular guide socket, the pin entering the
socket when the jaws approach each other, and leaving the socket
when the spacing between the jaws is increased sufficiently, as the
jaws leave each other.
[0017] In use, a succession of detonator housings are moved
intermittently in series along a path extending between the jaws,
in a direction perpendicular to the axis of the ring, with their
associated initiating elements in place, optionally held there by a
resiliently flexible sleeve or ferrule located coaxially between
the mouth of the detonator housing and the initiating element, the
detonator housings being aligned parallel to the ring axis, while
the jaws are spaced apart, with each detonator housing being placed
between the jaws and coaxially aligned with the ring axis, before
the jaws are moved together into tight abutment with each other to
clamp the detonator housing mouth between the jaws by means of the
segments, the segments moving radially inwardly towards the ring
axis to crimp the mouth of the detonator housing around the
initiating element.
[0018] The invention accordingly extends to a method of crimping
the mouth of a metal detonator housing around an initiating
element, the method including the steps of: [0019] moving a
succession of detonator housing in series intermittently along a
path extending between a pair of opposed jaws, the detonator
housings being in turn located in a stationary condition between
the jaws; and [0020] moving the jaws into abutment with each other
to grip a mouth of the stationary detonator housing located
therebetween by means of toothed segments mounted on the jaws
which, when the jaws are tightly in abutment with each other, form
a segmented ring defining, at its centre, a passage having a
toothed circumferential outline,
[0021] the segments being arranged simultaneously to move radially
inwards towards and into contact with the mouth of the housing
located between the jaws as the jaws approach each other, to crimp
the housing against the initiating element by the time the jaws are
in tight abutment with each other, the detonator housing being
coaxially aligned with the axis of the ring and the detonator
housings being moved in succession, while the jaws are spaced
apart, in a direction perpendicular to the ring axis, the jaws
being moved apart after the mouth of each detonator housing has
been crimped, to allow the succeeding detonator housing to be moved
into its stationary condition between the jaws, before the jaws are
again moved together to crimp the mouth of said succeeding
detonator housing.
[0022] In accordance with the method, moving the jaws into abutment
may be against a bias which acts to space the segments apart from
one another and to space the segments radially outwardly,
automatically to enlarge the ring, as the jaws move apart.
[0023] It is a feature of the invention that it allows the series
of detonator housings intermittently to be moved, typically in a
straight line, along a path extending between the jaws and
perpendicular to the ring axis, while the jaws are reciprocated in
synchronisation with the intermittent movement of the detonator
housings, between a tightly abutting condition with their segments
located around a crimped detonator housing mouth, and a condition
spaced apart to allow subsequent movement of the detonators along
the path, thereby permitting low crimping cycle times, as short as
about 2 s or less, for the crimping of each detonator housing
mouth.
[0024] The invention will now be described, by way of non-limiting
illustrative examples, with reference to the accompanying
diagrammatic drawings, in which:
[0025] FIG. 1 shows a sectional plan view of a device in accordance
with a first embodiment of the invention, in a direction parallel
to the axis of its ring of segments, with its jaws spaced
apart;
[0026] FIG. 2 shows a view corresponding to FIG. 1, with the jaws
tightly in abutment; and
[0027] FIG. 3 shows an exploded three-dimensional view from the
bottom and side, of a device in accordance with a second embodiment
of the invention.
[0028] Referring to FIGS. 1 and 2, reference numeral 10 generally
designates a device in accordance with a first embodiment of the
invention for crimping the mouth of a metal detonator housing (not
shown). The device 10 comprises, broadly, a pair of opposed
elongate-rectangular hardened mild steel jaws 12, 14, having a
length of 120 mm, a width of 40 mm and a thickness of 20 mm. The
jaws thus have 120.times.40 mm.sup.2 major faces, 120.times.20
mm.sup.2 side edge faces designated 16, and 40.times.10 mm.sup.2
end edge faces designated 18. In the drawings, the jaws 12, 14 are
viewed face-on to their major faces and are shown with their major
faces co-planar, one face 16 of the jaw 12 being opposed to one
face 16 of the jaw 14, the opposed faces 16 being shown tightly in
abutment at 20 in FIG. 2, and spaced apart by a spacing "S" in FIG.
1.
[0029] In the present example, the jaws 12, 14 are reciprocably
mounted on a hydraulic reciprocating mechanism (not shown) arranged
to reciprocate them simultaneously between a closed condition,
shown in FIG. 2, and a fully open condition in which they are
spaced apart sufficiently to allow a series of detonator housings
to be crimped to pass between the jaws in a direction parallel to
their edge faces 16. The direction of reciprocation is normal to
the faces 16 and is shown by arrow 22, and the direction of
movement of the detonator housings is shown by arrow 24.
[0030] It is to be noted that in FIG. 1 the jaws 12, 14 are not
shown fully spaced apart, but only partly spaced apart, the jaws in
their fully spaced-apart condition permitting a succession of
detonator housings to pass therebetween in the direction of arrow
24, midway between their opposed side edge faces 16, without being
interfered with by the guide pin 26 (described hereunder) provided
on the jaw 12. In other examples, the jaws may be movable by a
pneumatic reciprocating mechanism or by a mechanical reciprocating
mechanism such as a crank; and it will be appreciated that in other
examples only one of the jaws 12, 14 need reciprocate, the other
being stationary.
[0031] In the present example, the detonator housings are carried
past the jaws 12, 14 by a conveyor mechanism (not shown) situated
below the jaws 12, 14, the edge faces 16, 18 being vertical and the
major faces being horizontal, with the detonator housings
projecting upwardly from the conveyor mechanism to present their
mouths at a desired elevation between the opposed side edge faces
16. The conveyor mechanism moves a succession of detonator housings
intermittently in the direction of arrow 24 when the jaws 12, 14
are sufficiently spaced apart, and holds the detonator housings
stationary at other times. Only one detonator housing at a time
will be located between the opposed jaw faces 16, the spacing
between, and/or speed of movement in the direction of arrow 24 of,
succeeding detonator housings moved by the conveyor mechanism being
selected accordingly; and the movement of the detonator housings in
the direction of arrow 24 will be appropriately synchronised with
the reciprocation of the jaws 12, 14 so that the detonator housings
are moved in the direction of arrow 24 only when the jaws 12, 14
are sufficiently spaced apart, and are held stationary at other
times, particularly when interference with detonator housing
movement by the pin 26 arising from too close a spacing between the
jaws 12, 14 is possible.
[0032] As shown in the drawings, the pin 26 is held captive in a
passage 28 in the jaw 12, by a screw 30 which screws axially into
the inner end of the pin 26 and engages with a tapped extension 32
of the passage 28. The jaw 14 is in turn provided with a passage 34
which receives the part of the pin 26 which projects from the jaw
12, when the jaws 12, 14 are sufficiently closely spaced from each
other, to guide accurate movement of the jaws into face-to-face
abutment of their side edge faces 16.
[0033] Each jaw 12, 14 is provided, in its side edge face 16 which
faces the other jaw, with a semi-regular-hexagonal indentation 36
(see FIG. 1 in particular) which is broadly C-shaped and provides
three abutment faces 38, namely a central abutment face and a pair
of lateral abutment faces respectively on opposite sides of the
central abutment face. The faces 38 are flat and are directed
radially inwardly towards the axis 40 of the hexagon of which they
form part. Each of the lateral abutment faces 38 is provided with a
slot 42. Each slot 42 is located midway between the major faces of
the associated jaw 12, 14 and extends in a tangential direction
relative to the associated axis 40. Each central abutment face is
provided with a centrally positioned passage 44 which receives a
sleeve 46 as described hereunder (see FIG. 2).
[0034] Three hardened mild steel segments 48 are provided in each
indentation 36, namely a central segment and a pair of lateral
segments on opposite sides of the central segment. Each segment 48,
when viewed in a direction parallel to the axes 40, is broadly
equilateral-triangular in outline, having a broad end 49 which is
radially outermost, for abutment against an associated abutment
face 38, a pair of side faces 51 for abutment against adjacent
segments 48, and a toothed inner narrow end 53, having teeth which
extend parallel to the axes 40, the abutment in question taking
place when the jaws 12, 14 are in abutment, as shown in FIG. 2. The
broad ends 49 of the lateral segments 48 remain at all times,
however, in abutment with the lateral abutment faces 38 having the
slots 42.
[0035] Each of the lateral segments 48 has an insert 50 screwed
into a tapped socket in the broad end 49 of the segment 48, the
insert 50 providing a projection which projects radially outwardly,
relative to the associated axis 40, from the broad end of the
segment 48, into the associated slot 42 in the associated abutment
face 38. Location of this projection in the associated slot 42
holds the lateral segments 48 captive in the associated indentation
36, the lateral segments in turn holding the respective central
segments 48 captive in said indentations 36. One side face of each
segment 48 is provided with a part-cylindrical cavity 52 which
holds a cylindrical rubber biassing element in the form of a
cylindrical block 54 press-fitted into the cavity 52.
[0036] As shown in FIG. 1, each sleeve 46 contains a coil spring 56
under compression, each sleeve 46 projecting into a socket 58
provided therefor in the central segment 48 associated with the
central abutment face 38 having the passage 44 receiving said
sleeve 46. Each sleeve 46 thus projects from the socket 58 in the
associated central segment 58, into the associated passage 44 in
the associated abutment face 38, being a press fit in the socket
58, but being slidable in the passage 44. The coil spring 56 acts
against segment 48 at the inner end of the socket 58, and against a
plug 60 held in an extension of the passage 44 by a grub screw 62.
The springs 56 are omitted from FIG. 2 for ease of
illustration.
[0037] Two plastics cover plates are provided to cover the major
faces respectively of each jaw 12, 14. Minor projections of the
lower cover plate can be seen in FIG. 1 at 64. The cover plates are
bolted to the jaws 12, 14 by bolts 66 provided with washers 68, the
positions of the bolts 66 and washers 68 being illustrated
schematically. The cover plates act to enclose the segments 48 to
prevent unwanted movement of the rubber blocks 54 and the segments
48 in the direction of axes 40, while protecting against the
ingress of dirt.
[0038] It will be appreciated that, when the opposed faces 16 of
jaws 12, 14 are in tight abutment at 20 as shown in FIG. 2, the
broad end 49 of each central segment 48 abuts its associated
abutment face 38, the side faces 51 of adjacent pairs of the
segments 48 all being in abutment and the rubber blocks 54 all
being under lateral compression and forced laterally into their
respective cavities 52. The axes 40 will coincide and the segments
48 will form a segmented ring around a central axis, also
designated 40 in FIG. 2, provided by the coinciding axes 40 of FIG.
1. When the opposed abutting faces 16 of the jaws 12, 14 move
apart, the springs 56 push the central segments away from their
respective abutment faces 38, and the rubber blocks 54 push
adjacent pairs of segments 48 apart, as shown in FIG. 1. It will be
appreciated that, in FIG. 2, the ring of toothed radially inner
narrow ends 53 of the segments 48 combine to form a central passage
around the central axis 40, their teeth being parallel to said axis
40.
[0039] In use, as mentioned above, the conveyor mechanism, when the
jaws 12, 14 are sufficiently spaced apart, successively and
intermittently moves the detonator housings into position, in the
direction of arrow 24, to place them at the position of the central
axis 40 shown in FIG. 2, with the projections of the inserts 50
being located at the ends of their respective slots 42 which are
closest to the opposed edge faces 16 of the jaws 12, 14, and with
the rubber blocks 54 spacing the side faces of the segments 48
apart. When the jaws are moved together, with the detonating
housing held stationary and coaxial with the central axis 40,
engagement of the lateral segments 48 of the jaw 12 with the
lateral segments 48 of the jaw 14, via the two rubber blocks
projecting into the space "S" between the jaws 12, 14, compresses
the various rubber blocks 54 and forces them into the associated
cavities 52, while bringing the side faces of the segments 48 into
abutment. Simultaneously therewith, the springs 56 are compressed
to bring the broad ends of the central segments 48 into abutment
with their associated abutment faces 38; and the lateral segments
48 slide along their respective abutment faces 38 until the
projections of their inserts 50 are at the ends of their associated
slots 42 furthest from the opposed faces 16 of the jaws 12, 14, at
which stage the situation shown in FIG. 2 is reached, with the
opposed faces 16 in abutment.
[0040] It will be appreciated that, as the jaws 12, 14 move
together, as described above, the toothed radially inner narrow
ends of the segments 48 converge axially inwardly towards the axis
40 and towards one another, until they form the substantially
circular central passage shown around the central axis 40 in FIG.
2. When they reach the mouth of the detonator housing located
coaxially with the central axis 40, said toothed radially inner
ends act to crimp the mouth of the housing around the initiating
element (and any sleeve or ferrule holding the initiating element)
projecting in the housing. When the jaws 12, 14 are subsequently
moved apart, the rubber blocks 54 act automatically to space the
side faces of the segments 48 apart in each jaw 12, 14, while the
springs 56 automatically move the central segments 48 away from
their respective abutment faces 38, the projections of the inserts
50 of the lateral segments 48 moving back to the ends of the
associated slots 42 closest to the opposed faces 16 of the jaws 12,
14, the outer ends of the lateral segments 48 sliding along their
respective abutment faces 38.
[0041] Referring to FIG. 3, reference numeral 100 generally
designates a device in accordance with a second embodiment of the
invention, for crimping the mouth of a metal detonator housing (not
shown).
[0042] Parts of the device 100 which are the same as, or similar
to, those of the device 10 of FIGS. 1 and 2, are indicated with the
same reference numerals.
[0043] In the device 100, the pin 26 in the jaw 12 and the
complementary passage 34 in the jaw 14, have been dispensed
with.
[0044] The device 100 includes upper cover plates 102, 104 and
lower cover plates 106, 108. Bolts 66 protrude inwardly from the
lower cover plates 104, 108, through passages 110 in the jaws 12,
14, and engage threaded sleeves 112 protruding inwardly from the
upper cover plates 102, 104.
[0045] The device 100 also includes a guide pin 114 protruding from
each of the segments 48, with each guide pin nestling or located
movingly in a guide slot 116 provided in one of the lower cover
plates 106, 108. The guide pins 114 and guide slots 116 ensure
accurate and consistent movement of the segments 48.
[0046] It is a feature of the invention that the simple
reciprocating movement of the jaws 12, 14 (arrow 22), and the
simple intermittent movement of the detonator housings along their
path between the jaws 12, 14 (arrow 24) allow rapid cycle times for
the crimping of individual detonator housing mouths, expected to be
of the order of 2 s or less.
[0047] Finally, it is to be noted that, although in the examples
shown in the drawings the detonators are described as moving in the
direction of arrow 24, in other examples they can move in a
direction perpendicular or normal to the direction of arrow 24, and
parallel to the direction of arrow 22. In this case the jaws 12, 14
will not only be reciprocated towards and away from each other in
the direction of arrow 22, but will also be indexed simultaneously
in a direction parallel to the direction of arrow 24 into crimping
stations in which they can reciprocate towards and away from each
other, and out of said crimping stations in a direction parallel to
the direction of arrow 24, to allow subsequent movement of the
series of detonators, in a direction parallel to the direction of
arrow 22.
* * * * *