Core making machine

A core making machine wherein a selected blow plate is attracted to the blow head by suction and/or by one or more magnets so that the connection between the blow head and the plate can be terminated or established practically instantaneously without the utilization of screws, bolts and nuts, clamps, hooks or other conventional fasteners.

CROSS-REFERENCE TO RELATED CASE 
The core making machine of the present invention is substantially identical 
with that which is described and shown in the commonly owned copending 
application Ser. No. 082,847 filed Aug. 8, 1987 for "Core making machine", 
now abandoned. 
BACKGROUND OF THE INVENTION 
The invention relates to core making machines of the type wherein a blow 
head is used to direct sand in a pressurized gaseous carrier medium into a 
core box by way of a blow plate. More particularly, the invention relates 
to improvements in core making machines of the type disclosed, for 
example, in U.S. Pat. No. 2,705,821 to Peterson. 
It is known to supply a core making machine with a set of different blow 
plates wherein the openings are distributed in a manner to ensure proper 
introduction of molding sand into selected core boxes. A foundry normally 
employs hundreds of different core boxes and blow plates, and the core 
making machine is provided with means for separably connecting its blow 
head with a selected blow plate. Such connecting means normally includes 
screws which secure the marginal portion of a selected blow plate to the 
adjacent portion of the blow head. The unit including the blow head and 
the selected blow plate, which is affixed to the blow head, is thereupon 
attached to a so-called sand head or to any other suitable device which 
supplies to the blow head at least one stream of sand in a gaseous carrier 
medium for admission into a core box by way of one or more openings in the 
selected blow plate. As a rule, the interval of time which is required to 
replace a blow plate with a different blow plate is between 10 and 40 
minutes, depending on the size of the blow head and blow plate and on the 
number and nature of devices which are used to separably attach the blow 
plate to the blow head. Thus, each and every replacement of a blow plate 
entails a prolonged interruption of operation of the core making machine 
with attendant losses in output. The situation is aggravated if the 
fasteners which are used to separably connect the blow head with a 
selected blow plate and/or the fasteners which are used to separably 
connect the blow head to the means for supplying molding sand become 
contaminated or corroded by sand and/or as a result of exposure to 
moisture so that they cannot be readily detached or reapplied. This 
further prolongs the intervals of idleness of the core making machine. 
Still further, the connection between the blow head and a selected blow 
plate as well as the connection between the blow head and its carrier 
(such as a sand head) is likely to develop leaks in response to repeated 
attachment and detachment of the blow head from the carrier and/or a blow 
plate; this entails uncontrolled escape of conveyed sand with the 
pressurized gaseous carrier medium and improper filling of a core box 
and/or contamination of the area around the machine. The threads of screws 
or similar fasteners, as well as the threads in tapped bores for the 
shanks of such threaded fasteners, are likely to be damaged or destroyed 
in response to repeated separation and reattachment of the blow head so 
that the blow head can become completely separated from its carrier or a 
selected blow plate can become completely detached from the blow head 
while the machine is in actual use. 
German Pats. Nos. 972,225 (to Hansberg) and 1,177,291 (to Bachmann et al.) 
disclose core making machines wherein the manner of connecting blow plates 
to the blow head is not described and/or shown. It is assumed that the 
connections are separable. 
German Pat. No. 930,104 to Hansberg discloses a core making machine wherein 
a selected blow plate can be separably connected to the blow head by a set 
of screws. This also applies for the connection of a selected blow plate 
to the blow head in the core making machine which is disclosed by 
Peterson. 
As a rule, the blow head of a core making machine is a one-piece body 
(reference may be had, for example, to Bachmann et al. and Hansberg '104). 
This is considered to be desirable and necessary in order to reduce the 
number of parts as well as to reduce the likelihood of penetration and 
entrapment of sand between separable components. The discharge end of the 
sand head is directly adjacent the one-piece blow head. Such sand head can 
be removed only when the blow head is detached from its carrier, for 
example, a tubular housing for the sand head. The means for separably 
connecting the blow head to the carrier normally includes a set of screws. 
Since the replacement of a previously used blow plate with a different 
blow plate often necessitates the utilization of a different blow head as 
well as the utilization of a different sand head, each such change of 
setup involves a separation of the blow plate from the blow head which is 
installed in the core making machine, separation of the blow head from its 
carrier, removal of the sand head, insertion of a different sand head, 
attachment of a different blow head to the freshly inserted sand head, and 
attachment of a different blow plate to the freshly installed blow head. 
The reason that it is often necessary to replace a blow head with a 
different blow head and to simultaneously replace the sand head when the 
core making machine is to employ a different blow plate is that the 
distribution of openings in the freshly selected blow plate is or can be 
such that the previously used sand head and blow head cannot ensure 
adequate distribution of supplied sand to the openings so that the 
distribution of sand in the core box which is adjacent the freshly 
selected blow plate is unsatisfactory. If the total time which is taken up 
by a change of setup is between 10 and 40 minutes, a substantial part of 
such time is spent to separate the blow head from its carrier in order to 
gain access to the sand head. Moreover, it is customary to clean the sand 
head or an analogous sand supplying element on a daily basis. Each such 
cleaning operation must be preceded by detachment of the one-piece blow 
head from its carrier. This not only takes up much time but also 
necessitates repeated application and removal of fasteners which are used 
to separably connect the blow head to the carrier. Therefore, the useful 
life of such fasteners is relatively short. Moreover, and since the 
fasteners constitute or cooperate with means for centering the blow head 
on its carrier, the centering action invariably deteriorates with time as 
a result of extensive wear upon the fasteners and/or upon one or more 
centering elements which cooperate with the fasteners. 
OBJECTS AND SUMMARY OF THE INVENTION 
An object of the invention is to provide a core making machine wherein a 
blow plate can be replaced with a different blow plate within a minute 
fraction of the time which is required in conventional core making 
machines. 
Another object of the invention is to provide a core making machine wherein 
the parts which couple a selected blow plate to the blow head can stand 
much longer periods of use than the connection between the blow head and a 
selected blow plate in a conventional core making machine. 
A further object of the invention is to provide the improved core making 
machine with novel and improved means for separably connecting the blow 
head to its carrier, such as the part or parts which supply the blow head 
with a stream of sand in a pressurized gaseous carrier medium. 
An additional object of the invention is to provide the improved machine 
with novel and improved means for coupling a selected blow plate to the 
blow head in such a way that the condition of the coupling means is not 
adversely affected by repeated separation of blow plates from the blow 
head and attachment of fresh or different blow plates. 
Still another object of the invention is to provide the machine with a 
novel and improved blow head, with novel and improved blow plates and with 
novel and improved means for supplying sand to the blow head. 
A further object of the invention is to provide a novel and improved method 
of separably coupling a selected blow plate to the blow head of a core 
making machine. 
An additional object of the invention is to provide the machine with means 
for practically instantaneously establishing or terminating a connection 
between the blow head and a selected blow plate. 
The invention is embodied in a core making machine which serves to 
pneumatically convey sand into core boxes. The improved machine comprises 
a blow head member having sand admitting inlet means and sand discharging 
outlet means, means for supplying to the inlet means sand in a gaseous 
carrier medium, a blow plate member, and means for separably coupling the 
plate member to the head member adjacent the outlet means. In accordance 
with a feature of the invention, the coupling means includes means for 
attracting the plate member to the head member, i.e., the coupling means 
need not employ screws, bolts, bolts and nuts, clamps, hooks, pawls or 
like separably or pivotably mounted parts which must be manipulated in 
order to attach the plate member to the head member as well as to detach 
the plate member from the head member. 
In accordance with one presently preferred embodiment of the invention, the 
coupling means includes means for attracting the plate member to the head 
member by suction. To this end, the head member and the plate member are 
respectively provided with neighboring first and second surfaces and the 
attracting means can include at least one suction chamber in at least one 
of the surfaces and means (e.g., a vacuum pump or the like) for 
maintaining the pressure in the suction chamber below atmospheric 
pressure. At least the first surface surrounds the outlet means of the 
head member, and the machine preferably further comprises sealing means 
which is interposed between the first and second surfaces and at least 
partially surrounds the suction chamber. The suction chamber can 
constitute a circumferentially complete annular chamber which surrounds 
the outlet means of the head member, and the sealing means can include at 
least one first and at least one second annular sealing element. One of 
these elements surrounds the suction chamber and the other sealing element 
is surrounded by the suction chamber. 
Alternatively or in addition to the means for attracting the plate member 
to the head member by suction, the coupling means can comprise at least 
one magnet. Such magnet can be provided in the head member or in the plate 
member (preferably in the head member) and can include or constitute an 
electromagnet. For example, the electromagnet can include one or more 
conductors in the form of windings which are at least partially recessed 
into the surface of the head member to at least partially surround the 
outlet means, and the plate member is then made of or contains a 
ferromagnetic material, at least in the region or regions adjacent the 
conductor or conductors of the electromagnet. 
The head member preferably includes a substantially annular support having 
an annular surface which preferably constitutes the first surface (i.e., 
the attracting means is operative between the support and the plate 
member) and a substantially centrally located recess or socket surrounded 
by the annular surface. Such head member further comprises a nozzle which 
defines the inlet means and the outlet means and is preferably removably 
(loosely) received in the recess, preferably in such a way that it is 
confined in the recess solely by the adjacent portion of the plate member 
when the latter is attracted to the annular support of the head member. 
That surface of the nozzle which surrounds the outlet means is immediately 
adjacent or abuts the surface of the plate member. The plate member can be 
attracted to the support of the head member by suction and/or by one or 
more magnets. The nozzle can be made of or can contain a suitable plastic 
material. 
The means for supplying sand can include a tubular member having a 
discharge end which is adjacent the inlet means and can directly abut the 
nozzle. To this end, the discharge end can be provided with a radially 
outwardly flaring collar abutting that (rear) surface of the nozzle which 
surrounds the inlet means and faces away from the plate member. 
Alternatively, the collar can be omitted and the discharge end of the 
tubular element can extend into a relatively shallow annular seat provided 
in the nozzle and surrounding the inlet means. 
The means for supplying sand can further comprise a housing for the tubular 
element, and such housing can constitute or include an elongated tube into 
which the tubular element is telescoped and which has an enlarged annular 
end portion adjacent the head member. In accordance with one presently 
preferred embodiment of the invention, the nozzle directly abuts the end 
portion of the housing. 
The machine further comprises means for securing the head member to the end 
portion of the housing, and such securing means preferably includes means 
for separably connecting the aforementioned annular support of the head 
member to the end portion of the housing. The connecting means can include 
one or more fasteners which are inclined with reference to or which are 
parallel with the axis of the tubular element of the sand supplying means. 
The support can include an annular portion which constitutes a bottom wall 
for the recess and surrounds the inlet means of the nozzle. Such annular 
portion has a side or end surface which faces the recess, and the fastener 
or fasteners can extend from the end surface of the annular portion, 
through the annular portion and into the end portion of the housing. Each 
fastener can have external threads and the end portion of the housing is 
then provided with a tapped bore or hole for each fastener. 
If the discharge end of the tubular element has a radially outwardly 
flaring collar, such collar can abut the aforementioned end surface so 
that it is held between the annular portion of the support and the nozzle 
when the nozzle is held in its recess by the adjacent portion of the plate 
member. The nozzle can constitute a relatively short cylinder, and the 
support of the head member can be provided with a substantially 
cylindrical surface which bounds the recess between the aforementioned end 
surface and the aforementioned annular surface and surrounds the properly 
inserted nozzle. 
If the nozzle should not directly abut the end portion of the housing for 
the tubular element, the nozzle abuts the aforementioned collar of the 
tubular element. The support can surround the end portion of the housing, 
or the aforementioned annular portion of the support can abut an end face 
of the housing between the nozzle and the housing. The housing is then 
provided with an opening through which the discharge end of the tubular 
element extends, either into the aforementioned seat of the nozzle or to 
enable its collar to abut the end surface in the recess of the support. 
The novel features which are considered as characteristic of the invention 
are set forth in particular in the appended claims. The improved core 
making machine itself, however, both as to its construction and its mode 
of operation, together with additional features and advantages thereof, 
will be best understood upon perusal of the following detailed description 
of certain specific embodiments with reference to the accompanying 
drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The core making machine 1 of FIG. 1 comprises a composite blow head member 
15 (hereinafter called head or blow head) with one or more sand admitting 
inlets at 10 and one or more sand discharging outlets at 11, a blow plate 
member 6 (hereinafter called plate or blow plate), a device for 
pneumatically supplying sand to the inlet or inlets 10 in a gaseous 
carrier medium and including a tubular sand conveying element 2 and a 
tubular housing 3 for the element 2, and novel and improved means for 
separably coupling the blow plate 6 to the blow head 15 adjacent the 
outlet or outlets 11. The housing 3 has an enlarged annular lower end 
portion 16 which is a hollow conical frustum and is separably connected to 
an annular support or flange 21 of the blow head 15 by several threaded 
fasteners 17 whose axes are inclined with reference to the axis 14 of 
through tapped bores which are provided in a substantially cylindrical 
sleeve-like skirt 4 of the head 15 and their tips abut the conical 
external surface of the enlarged annular end portion 16 of the housing 3. 
The support 21 has an annular surface 12 which surrounds the outlet or 
outlets 11 and faces the adjacent surface 13 of the blow plate 6. The 
aforementioned coupling means includes means for attracting the surface 13 
to the surface 12 by suction and, to this end, the surface 12 is formed 
with a shallow circumferentially complete annular groove 24 which is 
surrounded by a first annular sealing element 23a and surrounds a second 
annular sealing element 23. These sealing elements are partially received 
in shallow annular grooves of the annular surface 12 so that they abut the 
surface 13 when the plate 6 is attracted to the head 15 in response to 
evacuation of air from the suction chamber including the groove 24. The 
means for evacuating air from the groove 24 (i.e., for maintaining the 
pressure in the groove 24 below atmospheric pressure) includes a vacuum 
pump 125 whose intake is connected to the support 21 by a suction pipe or 
conduit 25. The conduit 25 contains an adjustable valve 225 which can 
connect the groove 24 with the pump 125 or with the atmosphere. The 
character 125a denotes a switch which can be actuated to start or arrest 
the pump 125. The intake end of the conduit 25 communicates with a bore 
which is provided in the support 21 and communicates with the groove 24. 
The suction chamber includes the groove 24 as well as the space between 
the sealing elements 23, 23a. In fact, the groove 24 can be omitted 
because the sealing elements 23 and 23a can maintain the surfaces 12, 13 
at a requisite distance from each other so that these surfaces define an 
annular suction chamber as soon as the plate 6 is moved sufficiently close 
to the head 15. 
The connection between the head 15 and plate 6 can be terminated in 
immediate response to disconnection of the pump 125 from the conduit 25 
and/or in response to admission of atmospheric air into the suction 
chamber including the groove 24, either by way of the conduit 25 and valve 
225 or elsewhere. Thus, the blow plate 6 can be properly coupled to or 
disengaged from the head 15 within a minute fraction of the time which is 
required to apply or detach one or more screws, bolts and nuts or 
analogous conventional fasteners. The area of the portion of the surface 
12 between the sealing elements 23 and 23a is selected with a view to 
ensure that suction in the chamber including the groove 24 will suffice to 
reliably couple the plate 6 to the head 15 when the core making machine 1 
is in actual use. The magnitude of the force with which the plate 6 is 
attracted to the support 21 of the head 15 can also be regulated by 
appropriate selection of the pressure differential between the suction 
chamber and the surrounding atmosphere. The magnitude of the force which 
is generated to attract the plate 6 to the head 15 will depend, to a 
considerable extent, upon the weight of the plate 6. 
It is clear that the surfaces 12 and 13 can define two or more 
circumferentially complete annular suction chambers or otherwise 
configurated suction chambers without departing from the spirit of the 
invention. For example, these surfaces can define two or more concentric 
annular suction chambers each of which can be individually connected to a 
discrete vacuum pump or to a common vacuum pump so that the magnitude of 
the force with which the plate 6 is attracted to the head 15 can be varied 
in stepwise fashion. Such suction chambers can be separated from each 
other by single or plural sealing elements so as to ensure that the 
development of a leak between one of several suction chambers and the 
surrounding atmosphere or between two neighboring suction chambers will 
not appreciably influence the force with which the head 15 attracts the 
plate 6. It is equally possible to provide one or more annuli of 
relatively small suction chambers each of which extends along a certain 
arc (as considered in the circumferential direction of the support 21). 
The neighboring suction chambers of one or more annuli of relatively short 
chambers can but need not overlap each other in the circumferential 
direction of the support 21. It is also possible to provide the groove 24, 
or two or more circumferentially complete or otherwise configurated 
grooves, in the surface 13 of the plate 6. This may be desirable in 
certain instances, e.g., to reduce the weight of the plate 6. 
The annular surface 12 of the support 21 surrounds a recess 21a which is 
actually a bore or hole extending all the way through the support 21 and 
confining a discrete portion 5 of the blow head 15, namely a short 
cylindrical or elongated nozzle 5 which defines the aforementioned inlet 
or inlets 10 and outlet or outlets 11. The nozzle 5 has a front surface 5a 
which is preferably substantially flush with the surface 12 when the 
nozzle is properly received in its recess 21a, and the nozzle is held in 
such recess exclusively by the central portion of the blow plate 6 when 
the latter is attracted to the support 21 in response to evacuation of air 
from the chamber between the sealing elements 23 and 23a. At such time, 
the circular rear surface 8 of the nozzle 5 is adjacent to or lies flush 
against the flat underside 9 of a radially outwardly extending circular 
collar 7 forming part of the discharge end of the tubular element 2. The 
collar 7 is snugly and sealingly received in a shallow depression 3a in 
the end face of the enlarged annular end portion 16 of the housing 3. The 
nozzle 5 serves to guide the admitted particles of sand from the inlet or 
inlets 10 toward and through the outlet or outlets 11 and into the opening 
or openings 6a of the blow plate 6. The latter is then located on top of a 
core box (not shown) of any conventional design which can rest on a 
suitable base in a manner as disclosed and shown, for example, in the 
aforementioned patent to Peterson. The axial length of the nozzle 5 is 
preferably selected in such a way that its front surface 5a is flush with 
the annular surface 12 of the support 21 when the rear surface 8 abuts the 
collar 7 and the latter abuts the surface at the bottom of the depression 
3a in the end portion 16 of the housing 3. 
Cleaning of the preferably cylindrical nozzle 5 (whose axis preferably 
coincides with the axis 14 of the element 2) can take place immediately 
after the pressure in the suction chamber including the groove 24 is 
allowed to rise so that the plate 6 becomes separated from the support 21. 
The nozzle 5 can drop out of the recess 21a by gravity because it need not 
be positively secured to the support 21 and/or the skirt 4. Moreover, the 
nozzle 5 merely abuts the collar 7 at the discharge end of the tubular 
element 2. 
The cost of the improved core making machine 1 need not exceed the cost of 
a conventional machine. All that is actually necessary is to provide one 
or more suction chambers between the surfaces 12, 13 of the blow head 15 
and a selected blow plate 6 and to provide means (such as one or more 
pumps 125) for evacuating air from the suction chamber or chambers. The 
weight of the machine is actually reduced if one or more grooves are 
machined into the surface 12 or 13, and a reduction of weight is 
especially advantageous if one or more grooves 24 or similar or analogous 
grooves are provided in each blow plate because this facilitates 
manipulation of blow plates during transport to or from storage. 
An advantage of the sealing elements 23, 23a is that their sealing action 
improves in response to progressing evacuation of air from the suction 
chamber including the groove 24. 
A further advantage of the improved machine is that several of its 
components can be identical with or similar to the corresponding 
components of a conventional core making machine. Thus, if a conventional 
machine already employs a blow head with a flange-like support for a 
selected blow plate, such machine can be converted for operation in 
accordance with the present invention (i.e., so that the selected blow 
plate is merely attracted but need not be positively locked to the blow 
head) by the simple expedient of providing the blow head and/or each blow 
plate with means for defining one or more suction chambers when the 
selected blow plate is placed next to the outlet or outlets of the blow 
head, and providing means for evacuating air from the suction chamber or 
chambers. Conversion of a conventional core making machine for operation 
in accordance with the present invention can be carried out at a 
surprisingly low cost. 
The core making machine 1' of FIG. 2 employs a modified blow head 15' and a 
modified housing 3'. The manner in which the blow plate 6 can be 
pneumatically attracted to the support 21' of the cup-shaped head 15' is 
the same as described in connection with FIG. 1. The skirt 4' of the head 
15' has a radially inwardly extending annular portion 4a' which abuts the 
end face 3b' of the housing 3' and is secured thereto by a set of axially 
parallel fasteners 22 in the form of screws. The bottom surface 19 of the 
annular portion 4a' is the end surface in the deepmost portion of the 
recess 21a'; this recess receives the nozzle 5 of the head 15' and the 
rear surface 8 of the nozzle abuts the underside 9 of the collar 7. The 
latter abuts the end surface 19 and conceals the heads of the screws 19. 
The character 20 denotes an opening in the annular portion 4a' of the 
support 21'; the discharge end of the tubular element 2 extends through 
and beyond the opening 20. When the blow plate 6 is attracted to the 
support 21' of the head 15', the central portion of such plate urges the 
nozzle 5 into the recess 21a' and the nozzle biases the collar 7 at the 
discharge end of the tubular element 2 against the surface 19 of the 
annular portion 4a'. Thus, the head 15' and the housing 3' can be lifted 
relative to the collar 7 as soon as the pressure in the groove 24 of the 
surface 12' is permitted to rise so that the plate 6 becomes separated 
from the support 21'. Alternatively, the tubular element 2 can be lowered 
with reference to the housing 3' and support 21' as soon as the blow plate 
6 is permitted to become disengaged from the support 21' and the nozzle 5 
is permitted to leave its recess 21a'. This also contributes to a 
shortening of assembling and dismantling times and renders it possible to 
convert the machine for use with a different blow plate 6 within a minute 
fraction of the time which is required for such operation in a 
conventional core making machine. The same holds true for the intervals of 
time which are necessary to dismantle the improved machine for the purpose 
of gaining access to selected parts, such as the nozzle 5, for inspection 
and/or cleaning. 
FIG. 3 shows a core making machine 1" which is similar to the machine of 
FIG. 1 except that it employs a somewhat different tubular element 2 and a 
somewhat different blow head 15". In addition, the means for coupling the 
blow plate 6 to the support 21" of the head 15" includes an electromagnet 
26 having one or more annular coil-shaped conductors which are recessed 
into the annular surface 12" of the support 21" and are connectable to a 
suitable energy source (not shown) by a cable 27. At least that portion of 
the plate 6 which is adjacent the conductors of the electromagnet 26 is 
made of or contains a ferromagnetic material so that the plate can be 
attracted to the support 21" in immediate response to energization of the 
electromagnet. Inversely, the plate 6 is separated from the support 21" in 
immediate response to deenergization of the electromagnet 26. Thus, the 
machine 1" of FIG. 3 also allows for a substantial shortening of the 
interval of time which is required to assemble the plate 6 with the head 
15" or to detach the plate 6 in order to gain access to the nozzle 5 or to 
replace the illustrated plate 6 with a different plate. The rear surface 8 
of the nozzle 5 abuts directly the end face 3a" of the enlarged annular 
end portion 16" of the housing 3". The discharge end of the tubular 
element 2 is devoid of the collar 7 and is received in a shallow annular 
groove or seat 28 which is provided in the rear surface 8 and surrounds 
the inlet or inlets 10 of the nozzle 5. 
An advantage of the coupling means which employs one or more magnets is 
that the sealing elements 23 and 23a (whose useful life is likely to be 
short) can be omitted. The useful life of the sealing elements can be 
affected by the blow plate 6 when the latter bears against the sealing 
elements and/or by the conveyed granular material. 
An advantage of the simplified tubular element 2 of FIG. 3 (which is devoid 
of a radially outwardly extending collar) is that such tubular elements 
can be even more rapidly extracted from the housing 3", either upwardly or 
downwardly as seen in FIG. 3. 
Another advantage of the coupling means which employs one or more magnets 
as a means for attracting a selected blow plate to the blow head is that 
the surfaces 12" and 13 need not be machined with as high a degree of 
precision as if such surfaces were to define one or more suction chambers. 
Moreover, the development of dents, scratches and/or like damage to the 
surface 12" and/or 13 does not affect the force with which the magnet or 
magnets attract a selected blow plate to the blow head 15". 
If the magnet or magnets are installed in the blow head 15", the latter can 
cooperate with any conventional blow plate as long as the blow plate 
contains or consists of a ferromagnetic material so that it can be 
properly attracted to the support 21". The magnet or magnets are 
preferably installed in the head 15" because this reduces the overall cost 
of the machine (since it is not necessary to provide each of a hundred or 
more blow plates with one or more magnets) and also because it is simpler 
and more convenient to connect the normally stationary head 15" to a 
source of electrical energy and to means for connecting the magnet or 
magnets in the head 15" with or for disconnecting such magnet or magnets 
from the energy source. 
The fasteners 17 which are shown in FIGS. 1 and 3 cooperate with the 
enlarged annular end portion 16 or 16" of the respective housing 3 or 3" 
in a manner as known from certain conventional core making machines. Since 
the axes of the fasteners 17 are inclined relative to the axes 14 of the 
respective tubular elements 2, and since the tips of these fasteners bear 
against the conical external surface of the enlarged annular end portion 
16 or 16" of the respective housing 3 or 3", the fasteners 17 tend to pull 
the head 15 or 15" upwardly (as seen in FIGS. 1 and 3) so that the 
internal shoulder of the skirt 4 or 4" is urged against the underside of 
the annular end portion 16 or 16". 
An advantage of the connection which is shown in FIG. 2 and employs 
fasteners 22 which are parallel to the axis 14 of the tubular element 2 is 
that the fasteners are concealed when the core making machine 1' is in use 
and the head 15' cannot be accidentally loosened or completely detached 
from the housing 3'. Moreover, the enlarged end portion 16 of the housing 
3 of FIG. 1 can be omitted because the end face 3b' of the tubular housing 
3' can abut directly the outer side of the annular portion 4a' of the 
skirt 4'. The machine 1' of FIG. 2 can be simplified still further by 
replacing the illustrated tubular element 2 with the tubular element 2 of 
FIG. 3; the nozzle 5 of FIG. 2 is then preferably provided with a seat 
corresponding to the seat 28 of FIG. 3 in order to receive the collar-free 
discharge end of the tubular element 2 of FIG. 3. 
Concealment of the fasteners 22 is desirable and advantageous because they 
are less likely to be contaminated so that it would be difficult to remove 
them if the operators would decide to separate the head 15' from the 
housing 3'. 
The nozzle 5 can be made of a metallic material or of a suitable plastic 
material. A relatively lightweight plastic nozzle is often desirable and 
advantageous because it renders it possible to reduce the forces which are 
required to attract a selected blow plate 6 to the head 15, 15' or 15", 
i.e., to use a smaller vacuum pump or a weaker magnet. Moreover, the 
material of a plastic nozzle or of a plastic-coated nozzle can be selected 
in such a way that it can sealingly engage the adjacent surfaces of the 
blow plate, blow head, tubular element 2 or housing 3" and thus confine 
the conveyed solid and gaseous substances to one or more predetermined 
paths, even if the surfaces around the plastic nozzle are rough or 
scratched due to wear or improper handling. In addition, a plastic nozzle 
is normally much less expensive than a metallic nozzle. Still further, a 
somewhat elastic plastic nozzle can sealingly engage the adjacent portion 
of the surface 13 on the selected blow plate 6; this is important when the 
coupling between the head and the plate operates with suction. 
It has been found that, in many instances, the utilization of attracting 
means which operates with suction or the utilization of attracting means 
which operates with one or more magnets (such as one or more 
electromagnets) suffices to ensure reliable retention of a selected blow 
plate in an optimum position with reference to the support and with 
reference to the nozzle of the adjacent blow head. However, it is equally 
within the purview of the invention to use suction-operated attracting 
means jointly with one or more electromagnets, for example, if the blow 
head is to attract a large and heavy blow plate. 
It was also ascertained that the improved coupling between the blow head 
and a selected blow plate renders it possible to replace the blow plate 
within an interval of less than twenty seconds. The pneumatic and/or 
magnetic forces which are generated to attract a selected blow plate to 
the blow head can be readily distributed in such a way that the blow plate 
is uniformly attracted to the support of the blow head all the way around 
the outlet or outlets of the nozzle 5. This greatly reduces the likelihood 
of escape of sand laterally between the surfaces 12, 13 which are shown in 
FIG. 1 or between the corresponding pairs of surfaces in the machines 1' 
and 1" of FIGS. 2 and 3. Still further, the cost of installing the 
improved coupling means is surprisingly low, especially if one considers 
the advantages of the improved machine, particularly the drastic 
shortening of the interval of time which is required for attachment or 
separation of a blow plate or for a dismantling to the extent which is 
necessary to gain access to the nozzle 5 and/or to other parts for the 
purposes of inspection and/or cleaning. 
The manner of separably securing the head 15 or 15" to the housing 3 or 3" 
by fasteners 17 which are inclined with reference to the axes of the 
respective tubular elements 2 is desirable and advantageous when a 
conventional core making machine is converted for operation in accordance 
with the present invention. Thus, all that is necessary is to replace the 
blow head of a conventional machine with the blow head 15 or 15" and to 
secure such blow head to the housing 3 or 3" by two or more fasteners 17. 
These fasteners serve as a means for securing the blow head to the housing 
as well as to center the blow head on the housing. To this end, the 
housing 3 or 3" is normally furnished with a so-called centering ring 
which is subject to wear under the action of the fasteners 17 so that its 
useful life is relatively short or that its centering action is less 
satisfactory and the attachment of head 15 or 15" to the respective 
housing 3 or 3" takes up increasingly longer intervals of time and becomes 
more tedious and more complex during each renewed application of the blow 
head to its housing. 
The housing 3' and the blow head 15' of FIG. 2 are preferably used in newly 
designed (non-converted) core making machines. The housing 3' is simpler 
than the housing 3 or 3", and the fasteners 22 can be fully concealed so 
that they are less likely to be affected by sand and/or other corrosive or 
abrasive substances which could shorten their useful life and/or prevent 
rapid removal of such fasteners if and when the blow head 15' is to be 
separated from the housing 3'. Moreover, the aforementioned centering ring 
can be omitted and the centering action is not affected by the number of 
separations of the head 15' or by the number of reattachments of such head 
to the housing 3' because each fastener 22 invariably enters one of the 
axially parallel tapped bores in the end face 3b' of the end portion of 
the housing 3'. The dimensions of the annular portion 4a' of the skirt 4' 
and of the end portion of the housing 3' can be readily selected in such a 
way that the making of holes for the fasteners 22 does not affect the 
stability of the connection between the housing 3' and the blow head 15'. 
Two fasteners 22 (without a centering ring) suffice to ensure that the 
head 15' is properly centered with reference to the tubular element 2 and 
housing 3'. 
The length of the interval which is required to complete a change of setup 
depends on the period of time which is needed to replace a blow plate with 
a different blow plate as well as on the period of time which is needed to 
replace the means for supplying sand in a gaseous carrier medium if such 
replacement is necessary simultaneously with the replacement of a blow 
plate. In conventional core making machines, replacement of the sand head 
or of an analogous sand supplying element invariably requires complete 
separation of the blow head from its carrier, e.g., from the housing for 
the sand head. The need for complete detachment of the blow head from the 
housing for the tubular element 2 is avoided in my machine in that the 
support of the blow head is provided with a recess for the nozzle 5. Thus, 
and if the nozzle 5 must be replaced with a different nozzle whenever the 
blow head is to be connected with a different blow plate, such replacement 
of the nozzle takes up very little time because the nozzle is accessible 
and can drop out of its recess as soon as the application of a force to 
attract the blow plate to the support of the blow head is interrupted. The 
removed nozzle is then replaced with a different nozzle which is best 
suited to convey sand to the newly selected blow plate. 
Moreover, when the nozzle 5 is removed from or permitted to drop out of the 
support 21 or 21', the collar 7 of the tubular element 2 is immediately 
accessible and the entire tubular element can be extracted downwardly, as 
viewed in FIG. 1 or 2, for inspection or for replacement with a different 
tubular element. The situation is even simpler if the core making machine 
employs the tubular element of FIG. 3 because such tubular element can be 
withdrawn from the housing 3" in an upward direction or downwardly. 
Extraction of the tubular element 2 downwardly (i.e., through the support 
21") is possible as soon as the nozzle 5 is removed or permitted to fall 
out of its recess in the support 21". The just described mode of gaining 
access to and of removing the tubular element 2 takes up but a minute 
fraction of the time which is required in a conventional core making 
machine to remove the screws which secure the blow head to the housing for 
the sand head before the sand head can be reached for removal from its 
housing. 
The provision of a composite blow head 15, 15' or 15" wherein the support 
21, 21' or 21" has a recess for the nozzle 5 renders it possible to gain 
access to the tubular element 2 while the major portion (support) of the 
blow head remains attached to its carrier (housing 3, 3' or 3"). Thus, 
once the blow plate 6 is detached from the support of the blow head and 
the nozzle 5 has been caused or permitted to leave its recess in the 
support, the tubular element 2 can be withdrawn in a forward (downward) 
direction because, when it conveys a stream of sand, it abuts exclusively 
the rear surface 8 of the nozzle 5 and need not be positively connected to 
the housing and/or to the support of the blow head. The situation is even 
simpler in the embodiment of FIG. 3 wherein the discharge end of the 
tubular element 2 does not have a collar so that it is merely inserted 
into the annular seat 28 in the rear surface 8 of the nozzle 5. 
Immediate accessibility and removability of the tubular element 2 as soon 
as the nozzle 5 is removed from the recess of the support is of advantage 
in connection with the changes of setup as well as when the tubular 
element is to be cleaned which, as mentioned above, normally takes place 
on a daily basis. Furthermore, and since the support of the blow head can 
remain attached to its carrier, the wear upon the fasteners (be it the 
screws 17 or the screws 22) is minimal and such screws can stand long 
periods of use, especially if they are normally concealed in a manner as 
shown in FIG. 2 which employs the aforediscussed substantially cup-shaped 
support 21' and wherein the heads of the axially parallel fasteners 22 are 
concealed by the collar 7 as well as by the nozzle 5. 
Since the front surface 5a of the nozzle 5 is preferably flush with the 
surface 12, 12' or 12" of the respective support (i.e., the composite blow 
head of the present invention presents to the selected blow plate a 
practically uninterrupted surface including the surface 5a), the improved 
blow head can be used with all or nearly all conventional blow plates 
without risking the escape of large quantities of sand between the blow 
plate and the blow head. 
The likelihood of uncontrolled escape of sand and/or gaseous carrier medium 
along the rear surface 8 of the nozzle 5 is remote regardless of whether 
the tubular element has a discharge end with a flange 7 or a simple 
cylindrical discharge end as shown in FIG. 3. In FIGS. 1 and 2, the flange 
7 is confined between the rear surface 8 of the nozzle 5 and the bottom 
surface in the depression 3a of the housing 3 (FIG. 1) or between the rear 
surface 8 of the nozzle 5 and the surface 19 of the annular portion 4a' of 
the cup-shaped support 21' (FIG. 2). In FIG. 3, the discharge end of the 
element 2 fits into the seat 28 in the rear surface 8 of the nozzle 5 and 
the latter abuts the end face 3a" of the enlarged end portion 16" of the 
housing 3". 
The improved core making machine can embody only the novel (magnetic and/or 
suction-operated) means for coupling a selected blow plate to the support 
of the blow head, only the improved composite blow head (with the thus 
achieved ready accessibility and removability of the tubular element of 
the sand supplying means), or the novel coupling means as well as the 
improved blow head. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic and specific aspects of my contribution to 
the art and, therefore, such adaptations should and are intended to be 
comprehended within the meaning and range of equivalence of the appended 
claims.