Material handling apparatus

A manually manipulatable device for adjusting the position of a workpiece supported on a machine having relatively movable parts operated by electrically controlled, selectively energizable and deenergizable driving means comprises an elongate arm having a workpiece engageable fork at one end and a support at its other end for manipulation by an operator. The support preferably is pistol-shaped having a grip at one end and a barrel at its other end. The support includes two normally open, manually closable electrical switches in circuit with the machine's driving means to effect energization of the latter under the control of the workpiece manipulating device, but only when both of the switches are closed. The switches are spaced apart from one another a distance greater than that which can be spanned by the fingers of one hand of the operator, thereby preventing closing of both switches unless the operator's hands are on the support. The workpiece engageable fork and the support are spaced apart a distance sufficient to ensure that, when the fork engages the workpiece, the support is spaced from the machine a distance sufficient to ensure that the machine operator's hands are outside the machine.

BACKGROUND OF THE INVENTION 
There are many kinds of industrial machines having components which move 
relatively toward and away from one another during operation to perform 
one of a number of operations on a workpiece supported between the 
relatively movable components. Examples of such machinery are punch 
presses, forming and drawing die presses, and progressive die machines. In 
all of such machinery it is conventional practice, prior to commencing a 
production run, for the machine operator to adjust the relatively movable 
die members or the like for proper registration, manually place a 
workpiece in position between the relatively movable parts, and cycle the 
machine under manual control to verify proper adjustment of the relatively 
movable parts. 
In the case of a progressive die machine there conventionally is a 
plurality of pairs of die members spaced along a path that is to be 
traversed by a strip or ribbon of workpiece-forming material. Each pair of 
relatively movable dies constitutes a work or forming station and it is 
conventional for the ribbon material to be unwound from a reel, advanced 
incrementally into each station, and rewound on a second reel. 
Preparatory to commencing a production run of a progressive die machine, 
the die registration steps referred to earlier are performed at each 
station. In addition, the leading end of a ribbon of material 
conventionally is advanced by hand to each successive station during the 
preliminary machine setup operation. Further, when one reel of ribbon 
material has been exhausted following a production run, it is conventional 
for the leading end of a fresh ribbon material to be moved manually 
incrementally from station to station preparatory to automatic operation 
of the machine. 
In each of the foregoing cases the operator of a machine is exposed to 
substantial risk of injury in the event the relatively movable parts of 
the machine are caused to move while one or the other of the operator's 
hands is within the machine. Such risk is increased in those instances in 
which the operator is weary or becomes careless. 
An object of the present invention is to provide apparatus capable of 
manipulating a workpiece supported by a machine and which is constructed 
in such manner as to ensure that the machine cannot be cycled unless both 
hands of the operator are positioned on the manipulating apparatus and in 
a safe position external of the machine. 
SUMMARY OF THE INVENTION 
Apparatus constructed in accordance with the invention compirses an 
elongate device having at one end a workpiece engageable and manipulating 
member and at the other end a support. The support has a pair of normally 
open, manually closable switches in circuit with the driving mechanism of 
a machine, both of which switches must be held in their closed positions 
before the machine driving mechanism can be energized. The two switches 
are spaced from one another a distance incapable of being spanned by the 
fingers of one hand of an operator and are located in recessed or 
depressed areas to preclude inadvertent closing of either switch. The 
construction and arrangement of the apparatus are such that closing of the 
switches requires a deliberate act and requires the use of both hands of 
an operator, thereby avoiding the possibility that an operator's hand will 
be exposed to the risk of injury during use of the workpiece manipulating 
apparatus.

DETAILED DESCRIPTION 
Apparatus constructed in accordance with the invention is adapted for use 
with a number of different kinds of machinery and is disclosed as being 
used in conjunction with a progressive die machine 1 including an elongate 
base 2 having a number of successive, progressive die members 3 and 4. 
Above each die member 3 and 4 is a mating die member 5 and 6, 
respectively, carried by a vertically movable platen 7 supported on a 
frame 9. Each pair of die members 3,5 and 4,6 forms a work station. 
Extending longitudinally of the machine 1 and spanning the work stations is 
a ribbon or strip of steel, aluminum, brass, or other material, which will 
be acted on by the die set at each work station to form the material into 
an article of manufacture. Conventionally, the material 10 is wound on a 
reel 11 from which the leading end is extended and rewound on another reel 
12 following movement of the material from one end of the machine 1 to the 
other. The reel 12 conventionally is driven by an electric motor 13 via an 
incremental transmission 14 and a drive belt 15. The motor 13, when 
energized, operates continuously and the transmission 14 imparts rotation 
to the reel 12 in successive increments to advance the material step by 
step to each of the work stations. 
The reciprocable platen 7 may be connected by an arm 16 to a crank 17 
journaled on the frame 9 and coupled by a belt 18 to an electric motor 19 
which is energizable and deenergizable in a manner subsequently to be 
described. The motors 13 and 19 are synchornized in such manner that each 
time the die sets close on the workpiece 10, the latter will have been 
indexed the distance between adjacent work stations, as is well known in 
the art. 
During initial setup operations of the progressive die machine 1, or when a 
fresh strip 10 of material is to be conditioned for forming operations, it 
is conventional for the machine operator to introduce the leading end of 
the strip 10 to the first work station, energize the motor 19 to effect 
one cycle of operation of the platen 7, manually advance the strip to the 
next work station, recycle the platen 7, and so on until the leading end 
of the strip may be coupled to the rewinding reel 12. During these 
operations, the hands of the machine operator repeatedly will be placed in 
hazardous positions and severe injury to the operator may result if the 
platen is actuated inadvertently or intentionally. 
Apparatus constructed in accordance with the preferred embodiment of the 
invention is designated generally by a reference character 20 and 
comprises a manually portable support 21 of pistol configuration having a 
barrel 22 joined at one end to a grip 23 by means of a housing 24. The 
barrel 22 is provided with a socket in which is fixed one end of an 
elongate rod 25 terminating at its opposite end in a workpiece engaging 
fork 26 having stiff, but resilient, tynes 27. 
Between the outer end of the barrel 22 and the housing 24 is a pair of 
upstanding, spaced apart walls or ribs 28 which project above the surface 
of the barrel and thus provide a recess or depression 29. Fitted into an 
opening formed in the barrel at the recess 29 is a depressable push button 
30 that is projected outwardly by a spring (not shown). The barrel 22 is 
hollow to accommodate a switch 31 (FIG. 6) having normally open contacts 
which close in response to depression of the push button 30 and which 
reopen upon release of the push button. 
The housing 24 is provided at its rear end with rearwardly extending, 
spaced apart ribs 32 defining a depression or recess 33 therebetween. 
Fitted into an opening at the base of the recess 33 is a push button 34 
similar in all respect to the push button 30 and which, upon depression 
thereof, is operable to close the contacts of a normally open switch 35 
accommodated in the housing 24. The switches 31 and 35 are connected in 
series. 
The housing 24 and the barrel 22 are provided with passages therein for the 
accommodation of electrically conductive wires that emerge from the 
housing 24 via a coupling 36 to which is joined one end of an electrical 
cable 37, the opposite end of which is connected to a junction box 38. The 
junction box is suspended from a trolley 39 having wheels 40 which ride 
upon an overhead rail 41 that extends above and parallel to the length of 
the machine 1. The junction box 38 also is connected to one end of a cable 
42, the opposite end of which is connected to a source of electrical 
energy. The cable 42 preferably is supported at intervals on hangers 43 
suspended from wheeled trolleys 44 like the trolley 39. 
The housing 24 preferably includes a swivelable loop 45 to which one end of 
a chain 46 is connected, the opposite end of the chain being connected to 
a fitting 47 carried by the junction box 38. The apparatus 20 thus is 
suspended from the overhead rail 41 and is manually adjustable along the 
rail for the full length of the machine 1. 
If desired, the workpiece engageable fork 26, rather than being fixed 
directly to the free end of the rod 25, may be fixed to a sleeve 48 as 
shown in FIG. 5, and which telescopingly accommodates the rod 25 so as to 
enable the distance between the fork 26 and the support barrel 22 to be 
adjusted. A split clamp 49 encircles the sleeve 48 and is provided with an 
adjusting screw 50 which may be adjusted to secure the sleeve 48 in any 
one of a number of adjusted positions relative to the rod 25. 
As is illustrated in the simplified wiring diagram of FIG. 6, the motor 13 
for indexing the workpiece 10 incrementally relative to the machine 1 is 
connected to two electrical power lines L-1 and L-2 via a control switch 
51. The driving motor 19 for the platen 7 is connected to the power lines 
via a control switch 52, such switch being bridged by the switches 31 and 
35. 
When it is desired to condition the machine 1 for operation, the leading 
end of the strip 10 is led from the reel 11 toward the machine 1. The 
machine operator grasps the grip 23 of the manipulating device 20 and fits 
the edge of the strip between the tynes 27 of the fork 26. The operator 
then may feed the leading end of the strip between the die members 3 and 5 
at the first work station. Upon closing of both of the switches 31 and 35, 
the motor 19 will be energized to effect a cycle of operation of the die 
sets so as to perform a first forming operation on the leading end of the 
strip 10. Therafter, the operator may index the strip 10 manually through 
each of the remaining work stations, effecting cycling of the platen 
following indexing of the strip 10 to each station, until the leading end 
of the strip has been indexed the full length of the machine 1 and is 
secured to the rewinding reel 12. Thereafter, the machine may be 
conditioned for automatic operation by closing of the switches 51 and 52. 
An important characteristic of the invention is that the switches 31 and 35 
carried by the support 21 are spaced apart a distance greater than can be 
spanned by the fingers of one hand of the machine operator. Since both of 
the switches 31 and 35 must be closed to effect operation of the motor 19 
when the switch 52 is open, it is essential that both hands of the 
operator be on the support 21 to effect simultaneous closing of the 
switches 31 and 35. As a consequence, the likelihood that an operator's 
hand will be within the machine 1 and exposed to injury is extremely 
remote. 
The recessing of the switch-operating push buttons in the depressions or 
recesses 29 and 33 contributes to operator safety by minimizing the 
likelihood that either of the push buttons may be depressed to 
switch-closing position inadvertently. 
The disclosed embodiment is representative of a preferred form of the 
invention, but is intended to be illustrative rather than definitive 
thereof. The invention is defined in the claims.