USRE24491E

USRE24491E - Apparatus for recording and controlling

Info

Publication number: USRE24491E
Authority: US
Priority date: 1935-01-04
Publication date: 1958-06-17
Also published as: US2079050A

Description

June 17,1958 mass Re. 24,491

APPARATUS FOR RECORDING AND CONTROLLING MACHINE TOOL OPERATION 2 Sheets-Sheet 1 Original Filed May 16, 1950 June 17, 1958 R. E. CROSS ETAL 24,491

APPARATUS FOR RECORDING AND CONTROLLING MACHINE TOOL OPERATION Original Filed May 16, 1950 2 Sheets-Sheet 2 INVENTOR-S. 7244;; if d'ra 55,

g r Tessa/7.

United States Patent Ofiice Re. 24,491 Reissuecl June 17, 1958 APPARATUS FOR RECORDING AND CON TROL- LING MACHINE TOOL OPERATION Ralph E. Cross, Grosse Pointe Shores, and Werner H.

Jessen, Detroit, Mich., assignors to The Cross Company, Detroit, Mich., a corporation of Michigan Original No. 2,679,038, dated May 18, 1954, Serial No. 162,176, May 16, 1950. Application for reissue July 15, 1957, Serial No. 672,849

30 Claims. or. 340-267) Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

This invention relates to new and useful improvements in apparatus for recording the life of or wear on cutting tools.

Many types of machines, and particularly large multiple-spindle machines, are equipped with so many individual cutting tools that it is impossible for the operator to observe and keep account of all the tools. As a result, tools are often operated beyond their life expectancy and are broken or damaged beyond repair. When this condition exists, machines are overloaded and sometimes damaged, tool changing becomes a hit-and-miss operation causing loss of machine efficiency and valuable production time.

An important object of this invention is to provide an apparatus that automatically keeps track of the wear on each tool and that automatically shuts down the machine when the calculated life of any particular tool has expired.

Another object of the invention is to provide an apparatus of the above-mentioned character that indicates visually which tool needs replacing so that the operator can easily and quickly substitute a new tool for the worn one.

Still another object of the invention is to provide an apparatus of the above-mentioned character that in-- cludes a tool-control board on which the visual indicator is mounted and wherein a replacement tool and a gauge block for setting the tool in the machine are mounted side by side with the indicator for convenience in replacing the worn tool.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the drawings forming a part 'of this specification and wherein like numerals are employed to designatelike parts throughout the same,

Fig. l is a schematic view of a fluid system for visually indicating wear on the cutting tools,

Fig. 2 is a fragmentary view showing a modified construction of the type illustrated in Fig. 1,

Fig. 3 is a diagrammatic view of an electrical system embodying the invention,

Fig. 4 is a tool-control .board comprising a part of the invention, and

Fig. 5 is a top plan view of the board.

Reference is first had to Fig. l which shows a fluid system for recording the life of a cutting tool. Tool life as used in the application means the estimated number of operations a tool will perform between grinds. Broadly, the apparatus comprises a fluid pump, a glass tube for each cutting tool or group of similar tools in the machine connected to receive fluid from the pump, and metering valves for regulating the amount chargedto the tubes by the pump. I H

The operation of the pump is coordinated inany suitable manner with the operation of the machine so of liquidthat the amount of liquid charged by the pump to the tubes constitutes an index of the wear on the tools in the machine. Usually this canbest be done by operating and controlling the pump from the index or transfer control circuit of the machine. The metering valves are adjusted to displace a given amount of fluid for each operation of the index cycle, and the fluid is pumped into the transparent tubes which are visible to the operator. Thus, the amount of fluid in the tubes provides a visual record of the life and consequently the amount of wear on the tools. For example, if the tool or. group of tools identified by a tube has a calculatedlife of one hundred cycles, the metering valve is adjusted to charge an amount of fluid equal to one one-hundredth of the" capacity of the tube for each operating cycle of the machine. Thus, the tube is filled when the machine has cycled one hundred times, and the 'filled tube indicates to the operator that the tooljor group of tools identified vary the size of the tubes themselves, depending upon" theexigencies of the particular situation. Preferably, means is provided for s hut'ting down the machine when any particular tube becomes filled so that no tool will be operated beyond'its expected or calculated life span.

For a detailed description of the invention, attention is'directed to Fig. l which shows a relatively simple system having a single indicator tube and one metering valve.

will be appreciated that the utility of the apparatus increases directly as the number of tools in themachine. In a multiple-tube system, the tubes are connected to a common supply line, and the branch line leading to each tube is controlled by a separate metering valve. pump which supplies the fluid to the tubes must of course have at least suflicient capacity to supply all the tubes.

The'system shown in Fig. l is equipped with a conventional double-plunger pump;10 having a fluid reservoir 12 and provided with a reversing valve designated generally at 14. from the .outlets of reversing valve 14 to the inlets of a conventional hydraulic measuring valve 20. The valve 20 ejects a measured amount oftlie liquid chargedv thereto.

' into a pipe 22 which leads to a fitting 24 at the bottom member 32 normally closes the upper end of an overflowline 36 which leads back to the fluid reservoir'12. Liquid rising in tube 26} lifts the float member 32 to close.

switch 34, and when the float'member-is' raised sufficiently to close switch 34, it opens the overflow line 36 so that any excess fluid charged to the tube is merely: returned to the reservoir 12. A drainpipe38 controlled by valve 40 extends downwardly fromfitting 24 and connects-with the overflow pipe 36 as shown so that liquid in the tube 26 can be drained to the reseryoir .12.

when desired.

In operation, the pump 10 is connected in the control circuit of the machine so that it is operated once for each, operating cycle of the machine. Conveniently, the pump can be operated by and duringthe index or transfer cycle of the machine. The pump charges fluid alternately to

pipes

16 and 1 8 and, as suggested, fluid charged to the metering valve 2!) from either of the It'will be readily apparent, however, that any desired number of tubes and valves may beused and it' The Dual discharge pipes 16 and 18 extend pipes 18 is discharged to the tube through pipe 22. In this manner a measured amount or increment of liquid is charged to the indicator tube 26 for each operating cycle of the machine. An equal amount of liquid is charged to the tube for each operating cycle, and as these liquid increments accumulate, the tube is progressively filled withthe liquid. Thus, the level of liquid in the tube 26 at any given time is a function of the wear on the cutting tool or tools identified by the tube. As suggested, the amount of liquid charged to the tube 26 is co-ordinatedwith the expected life span of the cutting tool or tools so that the tube is filled and operates the float 32 to close switch 34 at the end of the calculated life span of the tool.

The switch 34 can be connected in the control circuit of the machine in any known or desired manner. For example, the switch 34 can be connected in the electrical circuit of the machine so that, when closed, it energizes a relayv which in turn opens a switch in the main control circuit of'the machine so that the machine is shut down until the worn tool has been replaced and the liquid has been drained from'the tube by opening valve 40. When the valve 40- is again closed, the-apparatus is reset for further operation.

Fig. 2 shows a modified construction wherein two electrical contacts 42 and 44 are mounted at the top of tube 26. This form of the invention is particularly suitable for use with an electrically conducting liquid such as mercury orthe like. When the liquid in tube 26 rises sufiiciently to engage contacts 42 and 44, a circuit is completed which breaks the electrical circuit supplying the'maehine. This automatically terminates the machine cycle when any tool in the machine has reached its limit, thereby making it mandatory for the operator to change the tool and drain the tube 26 before the machine can again proceed.

Attention is now directed to Fig. 3 which shows another formof the invention using an electrical apparatus instead of thefluid apparatus first described. In many ways the electrical apparatus is superior to the fluid apparatus and for most installations it is the preferred form.

Considered in certain of its broader'aspects, this form of the invention comprises an electrical circuit having an indicator instrument for registering and measuring the i life of each toolor of a group of similar tools in the machine and allcontrolled by a master timer. indicators provide a visual record of the used and'unused'portions of the tools. The'master timer is connected' to the operating circuit of the machine and provides operating current intermittently for the indicators. in the case of the'prime mover in'the form-of the invention first described, the master timer conveniently may be energized by the action of. the transfer bar or index mechanism of the machine. The indicators are provided with dials and indicating hands which travel toward zero as the master timer feeds current to them. When any indicating hand reaches zero, anelectrical contact is made which opens the control circuit of the machine and prevents further operation thereof. When the machine is shutdown in this manner the operator merely locates the dial which has completed'its cycle of operation', changes thetool identified thereby, resets the dial,

and restarts the machine.

More specifically, current from any suitable source of I electrical energy is supplied to the timing and control circuit embodying theinvention through lines 50 and 52. Current from thepositive line 50 flows through-line 54 to'the master timer motor 56 and thence through line 58 more negative line 52, The motor shaft,"-designated generally at 60, [carries a driving] drives a clutch member'62' which co-operates with a driven clutch member 64 [011-] connected to a shaft 66' to rotate or'oscillate a switch-actuating arm 68. These parts are illustrated diagrammatically in the-drawing and'th'e arm 68 is oscil The lated against the action of a spring 70 which normally holds the arm against an adjustable stop 72. The shaft 66 is oscillated axially to engage and disengage

clutch members

62 and 64 by a relay 74 which is connected across the main lines 50 and 52 by line 76, main control switch 78, and lines 80 and 82. Normally closed switches iii) 84 and 86 are provided in lines 58 and 82 respectively, and the switches are interconnected by member 88 for mutual operation. The-lateral arm 90 on the interconnecting member 88 is disposed for engagement by switch arm 68.

Thus, in the circuit here shown by way of illustration, the master timer motor 56 operates continuously as long as electrical energy is supplied to lines 50 and 52. However, clutch members 68 and 62 normally are disengaged so that no useful purpose is served by energization of the motor- 56. However, assoon as the starting switch 78 is closed, and this switch conveniently may be located for actuation by some part of the machine, the relay 74 is energized to engage

clutch members

62 and 64. When the clutch members engage, arm 68 is rotated or oscillated in the direction of the arrow until it engages arm 90 and opens switches 84 and 86. Switch 84 opens the circuit through motor 56, and switch 86 deenergizes relay 74 to again disengage

clutch members

62 and 64. Thus, the circuit remains energized only during the time it takes arm 68 to move from its initial full-line position to the dotted-line position. In one installation the circuit was energized for exactly three seconds.

Alsoconnected in the circuit are indicators having motors designated 92, 94, 96, and 98. It will be readily appreciated in this connection that four indicators are here shown merely by Way of illustration. In actual practice there may be a hundred or more of these indicators. The actual number in any particular instance of course depends upon the number of cutting tools inthe machine. One indicator usually will be provided for each tool in the machine. The shafts 100, 102, 104, and-106 [of indicator] are driven by the

motors

92, 94, 96,and 98 and are equipped with

cams

108, 110, 112, and 114 having

radial projections

116, 118, 120, and 122 respectively. The cams are adjustable to an initial position, and the cam projections are advanced progressively by their respective motors which, as pointed out above, are energized for a short period of time during each operating cycle of the machine. As hereinafter brought out in detail, when any of the cams has completed its cycle of rotation it opens a switch to de-energize the circuit and shut down the machine.

Indicators are available on the market which operate for from five minutes to ten hours. Thus if a fiveminute indicator is energized for three seconds during each operation of the machine, it has a maximum capacity to count out one hundred cycles. A ten-hour indicator,

- on the other hand, has a maximum capacity of twelve thousand cycles. If it is necessary to count a still larger number of cycles, an interrupter timer may be introduced into the circuit. Interrupter timers further divide the time of the master timer thus providing smaller time intervals of current for the indicators. In this way it is possible to obtain counts as high as two hundred thousand. An interrupter timer motor 124 is shown in the instant circuit and, by way of illustration, indicators 96 and 98 only are controlled by the interrupter timer.

More specifically, the part of the circuit which supplies the indicators and the interrupter timer includes a relay 126 which is connected'to lines 80 and 82 and operates the normally open switches 128 and 130; Switch 128 is in a holding circuit which shunts the main switch 78 and comprises

lines

132 and 134. Switch 130, on the other hand, is in the main circuit which feeds the

indicator motors

92, 94, 96, and 98 and the'interruptertimer motor 124.

More specifically, current flows through theswitch 130 from'li'ne 50 through line 136, thence through line 138' tothe auxiliary timer motor 98, and thence throughline,

Similarly current. travels to the indicator motor 96 through line 150, and the motor is connected to line 140 by line 152.

The interrupter timer motor 124 is connected between lines 138 and 52 ahead of indicator motors 96 and 98 by lines 154 and 156.

Normally closed switches 158, 160, 162, and 164 are connected in lines 142, .146, 150, and 138 which

supply indicator motors

92, 94, 96, 98 respectively, and these switches are operated by the

cams

108, 110, 112, and 114 of the indicator motors. Also, a switch 166 is connected as at 168 to operate inunison with switch 158, a switch 170 is connected as at 172 to operate in unison with switch 160, a switch 174 is connected as at 176 to operate in unison with switch 162, and a switch 178 is connected as at 180 to operate in unison with switch 164.

Switches

166, 170, 174, and 168 are connected in series with each other and with the starter 182 of the machine by

lines

184, 186, 188, 190, and 192, and the starter is connected to the negative side 52 of the circuit by line 194. Line I 140 which carries current traversing the indicator motors 96 and 98 is controlled by a switch 196 which is held normally open by spring 198 and is closed against the action of the spring by a cam 200 onthe shaft 202 [of] driven by the interrupter motor 124. The lobe of cam 200 extends around one third of the cam surface so that the switch 196 and consequently indicator motors 96 and 98 are energized every third operation of the machine.

Thus, if itis assumed that the master timer energizes;

the circuit for three seconds during each operation of the machine, it will be readily apparent that the

indicator motors

92 and 94 and the interrupter timer motor 124 are energized for the full three seconds interval. .During this time the motors will rotate the

cams

108, 110, and 200. Since indicator motors 96 and 98 are controlled by the cam 200, they are energized every third cycle or" the machine and thus operate only one third as tastes the other indicators. As soon as any of the indicator cams has completed its cycle of operation it opens the switches associated therewith and thusprevents energization of the motor associated therewith and of the machine starter 182. When this occurs the machine is shut down, the operator locates the indicator responsible. for the shutdown, changes the tool or the group of tools identified by the indicator, and resets the indicator to its normal initial position.- The machine is then free to operate until another indicator shuts down the machine and thus lets the operator know that another tool or group of similar tools has operated for its full calculated life expectancy.

For convenience, the indicators preferably are mounted on a tool-control board 210 as shown in Figs. 4 and 5. For greatest convenience in operation, the indicators preferably are mounted on. a middle panel 212. Replacement tools 214 are mounted in separate panels 216 disposed on opposite sides of and adjacent tothe middle'panel 212, and

conventional gauge blocks 218 for use in placingthe tools in the machine are mounted in outside panels 229.? The indicators and their respective tools and gauges convenheads of the machine, and the various areas of the board occupied by the groups preferably are painted distinctive contrasting colors to assist the opera-tor in locaii'ng'any: particular tool on the machine. -In the drawings, the board 210 is divided into three sections designated A, name respectively. The indicators are permanently mounted on the middle panel 212. The tools 214 and gauges- 21 8 are 1]? of 'said ism; and" an electricallypperated mechanism 'in-' removably mounted. on their respective panels as by iri-" sertion through suitablyloca ted openings in the panels.

The indicators conveniently are equipped with indicating pointers 222 which travel around a dial or scale 224 so that the operator can tell at a glance the amount of wear on any particular tool and can easily ascertain approximately how long it will be before any particular tool needs replacement. The dials 224 are equipped with adjustable stops 226 and when the indicator is reset the pointer 222 is turned back against the stop 226. In this manner the. indicator can be readily adjusted to operate for any particular interval within its range of operation. In the particular board here shown by way of illustration, each .dial 224 is provided immediately adjacent to and in front of the zero position with a red stripe 228 which constitutes a warning area. When the pointer 222 enters the red area 228 of any indicator the operator is immediately apprised that the tool or group of tools identified by the. indicator will soon require replacement.

The red warning area 228 designates a predetermined tified by the indicator which shuts down the machine but also any tool or tools identified 'by indicators having pointers within the red area 228.- In one installation the red areas 228 of the various indicators were of a size to designate two hours of operation by the machine. Thus, if the operator changes the tools as suggested above he is assured that the machine will have at least two hours of continuous operation before another shutdown occurs. Thus, the provision of the red areas 228 on the dials and operation of the machine in the manner described prevents the machine from being shut down repeatedly in a short time by the instant apparatus. In some of the larger machines having a hundred or more cutting tools, production time of the machine is of primary importance.

It may thus be seen that we have achieved the objects of our invention. We have provided an apparatus that can be readily adapted to any machine tool. The recording devices of the apparatus automatically keep track of every tool in the machine, prevent the tools from being operated beyond their expected life span, prevent damage to the tools and to the machine, assure efficiency in operation, and preventloss of valuable production time.

Having thus described the invention, We claim:

1. A machine having a tool, means for actuating said tool including an electrical operating circuit for the machine and a movable part operable in timed relation with said tool, electrically operated indicator means, an electrical control circuit connected to said indicator means, a master timer electrically connected to said control circuit operable to energize said indicator means for a predetermined periodof time during each operation of the timer, a' switch in "said control circuit controlling said master timer and operable by the mentioned part of the machine to energize said timer once for each operation of the tool, said indicator means including a dial having indicia thereon representing the life span of said tool and said indicia having a terminal point, a rotatable adjustable stop movable around said dial from said terminal point to a position representing an estimated life span for said tool, a rotatable pointer movable around said dial between said terminal pointfand said stop, said pointer being positionable against said step and operable during energization of said indicator means by said master timer so that successive operations of the machine indexes said pointer progressively around said dial toward said terminal point, and means adjacent the terminal point of said dial co-operable with said pointer to indicate when the latter is a selected time interval in terms of machine operation from said cluding a pointer on and" rotatable relative to said diltli an electric circuit for-said mechanism;*a timer mecha nism operated by said part and' 'controlling'said' circuit for energizingsaid mechanismfor a predetermined pe riodof time so as to advance said'pointer'one increment" of a dial space for eachoperation' of:said tool, a rotatably adjustable stop on'saiddial engageable'witli'said-pointer and positionable to locate thepointer initially ataselected starting position on the dial representingthe estimat ed life span of said tool, 'and'indiciann" saiddialcooperable with said'pointerto'designate' when a predetermined time interval in terms of ma'chineoperation re-' mains of the estirnatedlife span of said tool;

3. In combination with a machine havingja movable"? tool and a part operable in timed'relation' with saitlt'ool," an electrically operated mechanism including coactive stationary and rotatable members, one of said members being in the form of a dial and the other of'said' members being in the form of a pointer, means onsaiddial designating a life span. of said tool, an electric circuit for said mechanism, a timermechanism. operated bythe mentioned part of said machine controlling said..cir-' cuit for energizing saidmechanism for a predetermined period of time and operative to rotate said rotatable member as a consequence of tool operation, adjustable stop means coactive with said rotatable member to locate the. same initially at a selected starting position relative to. said stationary member representing an estimated life span of said too'l,'and means on said stationary member coactive with said rotatable member for designating when. a predetermined timeinterval'in terms .of machine operation remains of the estimated lifespan of said tool:

4. In combination with a machine having a movable tool and a part operable in timed relation withisaid'tool, a dial having indicia thereon. designating a life span of said tool, an electrically operated mechanism including a pointer on and rotatable relative to said dial, an electric circuit for said mechanism, a timer mechanism operated by said part and controlling said circuit for energizingsaid mechanism to move said pointer a predetermined distance on said dial for each operation of said tool, a rotatably adjustable stop on said dial engageable' with said. pointer and positionable to locate the pointer initially at a selected starting position. on the dial representing the estimated life span of said tool, and means on said dial co-operable with said pointer to designate when a pre-. determined time interval in terms of machine operation remains of said estimatedlife span;

5. In combination with a machine having a movable tool'and a part operable in'timed relation with said' tool, an electrically operated mechanism including relatively rotatable members, one of'sai'd members being manually] rotatable relative to'the other of said members to mselected starting position representing an estimated life span of said tool; an electric circuit for said mechanism, a timer mechanism operated by said part and controlling. said circuit for energizing said mechanism as a consequence of tool operation to movesaid one member relative to said other member'a predetermined distance for each operation of the tool, adjustable stop meanscoactive with said rotatable'member to locate"the'. same initially at a selected starting position relative to said. other member, and means coactive withsaid rotatable member for designating when a predetermined time interval in terms of'machine operation remains. of said estimated life span. 1

6. In combination with a machinehavinga movable tool and a part operable in timed relationwith. saidtool, a dial having indicia thereon designatinga life. span of said tool, an electrically operated mechanismincluding a pointer on androtatable relative to saiddial, an. electric circuit for said mechanism, a timermechanism, operated by said part and controlling said-circuit for energizing said mechanism to" move said pointer. a; predeterminedau able elementinisaidsecond circuit operatively, connected:-

distanceon" said diallfor 'each, operation of .said tool,- stops means onsaid' dial engageable with said' pointerand po-- sitionableto-loeate "the 'pointer initially at fl'SClCClCdSiZtlting position on the dial representing the estimated life span of said tool, and means cooperable"withsaidpointerto designate-when'apredetermined time interval in terms of machine-operation"remains of the=estimated-life span of said tool.

7. Incombination with a machine having a movable tooland a partoperable in timedrelation with said tool;

tool'andmeans co-operable'with said pointer to designate when-'a predetermined time interval in terms of'machineoperation remains of the estimated life span'of said'toolr 8; In an electrical controlsystem for a machine havinga tool which has an estimated life the magnitude of which is a function of the work performed thereby; at"

least oneswitching apparatus including a circuit-controlling deviceand' an energizable element for actua-tingsaid circuit-controlling device, a first' control circuit for such machine including a portion of said controlling device,- saidportion normally being=efiective-to maintain said circuit in'a normal'condition to render 'such'machine in: a condition to perform its intended functionya second control circuit including said energizable element and'a portion of said controlling device and normally-main tained-ina normal operating condition by said controlling device, a second" circuit-controlling device actuatable from a first circuit-controllingcondition to a second'cir cuit=controlling condition as a function of the work per formed by such tool, said second circuit-controlling de-* vice being: associatedwith said second circuit andefliective when said second circuit is in its normal condition to actuate said'energizable element as a function of the'" work performed by such tool, said s'witching apparatus further including means actuated as a function of the'ener gization of said energizable element to'actuate said firstnamed circuit controlling device to render said circuits out of their. respective saidnormal conditions.

9; In an electrical'control'system" for a machine protvidedwith' a toolhaving an estimated'life which is a function of the Work performed thereby, at least one switclv ing apparatus including a first circuit-controlling device,

and an energizable element foractuatingsaidcircuit-con trolling device, a first control circuit for said'machine' in eluding a'portion of said controlling device, said portion" normallyconditioning said circuit to'render saidv machine operative, a second circuit-controlling device actuatable asa function of the work performed by said tool,-and"a second control circuit associated'with said secondci'rcuitcontrolling-device and including said energizableelement' anda portion of said firstcircuit-controlling device nor malllyrconditioned: by said controlling devices to energize said;- energizable elementas. a function of? the work" per-.

formed by; said'tool, saidswitching apparatus furtheriina. eluding means actuated asa function of the energization'of" saidenergizable element to open said first and secondcontrol circuits.

10. An electric control system for a machine provided.

withatool having an estimated life which. is a function. ottherwork performed thereby, a. primary control circuit.

for said machine, asecond control circuit, first and-second:- normally-closed switches, each in a respective onex. of. said circuits-,anactuator for said'switches, anenergiz to said switch actuator, and means in said second circuit operable as a function of work performed by said tool to energize said energizable eiement for fixed predetermined time intervals.

11. In an electrical control system for a machine having a' tool which has an estimated life the magnitude of which is a function of the work performed thereby, at least one switching apparatus including a circuit-controlling device and an energizable time-integrating element, said integrating element being operatively associated with said circuit-controlling device to actu said circuitcontrolling device subsequently toa prcd rmined integrated tirne period, a first control circuit for such machine including a portion of i said circuitcontrolling device, said portion normally being effective to maintain said circuit in a normal condition to render such machine in a condition to perform its intended function, a timing element, a second control circuit including said integrating element and said timing element and a portion of said controlling device, a second circuit-controlling device actuatable from a first circuit-controlling condition to a second circuit-controlling condition as a function of the work performed by such tool, said second circuit-controlling device being associated with said second circuit and effective when said second circuit is in its normal condition to actuate said timing element whereby said integrating element is energized for a predetermined time integral as a function of work performed by such tool, said first-named circuit-controlling device being operable as a consequence of its actuation by said integrating element to render said first circuit in a condition to render said machine ineffective to perform its intended function and also to render said second circuit ineffective to actuating said integrating element.

12. An electrical timing network for controlling the operation of a machine including at ieast-two tools having different estimated lives comprising at least a pair of electrically energizable devices, an actuator individually associated with each device and having a first and a second operating condition, each of said actuators being normally maintained in its first operating condition and rendered into its second operating condition as a function of the energization of its respective device, switch means individually associated with each actuator and moved from a first circuit-controliing position to a second circuitcontrolling position as a consequence of its respective actuator being actuated from its first to its second operating'condition, a first electric circuit controlling the operation of such machine and including a first portion of each of said switch means arranged to render said circuit in a first operating condition solely when all of saidswitch means are in their respective first circuit-controlling positions, a plurality of control circuits, each said control circuit being individual to and including an individual one of said energizable devices and further including a second portion of the respective switch means associated with the respective energiz-able devices, each control circuit being effective to energize its respective euergizable device solely when its respective switch means is in its first circuit-controlling position, a master circuit controller arranged to be associated with such machine and actuated from a first to a second operating condition as a function of the operation of the tools of such machine, and a master circuit including said master circuit controller and said control circuits for controlling the energization of said control circuits as a consequence of the actuation of said master circuit controller from one of its operating conditions to the other of its operating conditions.

13. The combination of claim 12 in which at least one of said control circuits is provided with a proportioning switch and an energizable actuator is provided for controlling said proportioning switch and energized as a consequence of the operation of said master circuit controller, said last-named actuator being operable upon energization to control said proportioning switch whereby the one of said control circuits which is provided with said proportioning switch is subject to control thereby wellas by said master circuit controller.

e 14. An electrical timing network for controlling the operation of a machine including at least two tools having different estimated lives comprising at least a pair of' electrically energizable timedntegrating devices, a switch actuator individually associated with each device and movable from an initial toa switch-operating position as a function of the length of time said device is actuated,

a pair of normally closed switches individually associated with each switch actuator and movablefrom a circuitclosed position to a circuit open position as a consequence of its respective switch actuator being moved to its switch-operating position, a first electric circuit controlling the operation of such machine and including a first switch of each pairof switches arranged in series circuit whereby such machine is rendered in a first operating condition,

solely when all of said first switches are in their respective circuit-closed positions, a plurality of control circuits, each said control circuit being individual to and including an individual one of said integrating devices and furv circuit switch for energizing said control circuits for a predetermined time interval each time said master switch is closed. I

15. The combination of claim 14 in which at least one of said control circuits is provided with a proportioning switch and a time integrating device is provided for controlling said proportioning switch and rendering said proportioning switch in its open and closed positions as a function of the integrated time that said last-named time device is energized.

16. Apparatus for programing tool changes for a ma chine tool of the type having a tool adapted to perform work on a workpiece and including a member operable in timed relation to and in accordance with the work per formed on said workpiece comprising a dial, means on said dial designating a life span of said tool, an electrically operated mechanism including a pointer on and rotatable relative to said dial, said pointer being initially manually rotatable to a selected starting position on the dial representing the estimated life span of said tool, an electric circuit for said mechanism, means operable by said' member and controlling said circuit for energizing said mechanism periodically in accordance with work performed by the tool to move said pointer successively and progressively from said starting position and relative to said dial, adjustable stop means coactive with said pointer to position the same initially relative to said dial, and means on said dial coa-ctive with said pointer for designating when a predetermined time interval in terms of machine operation remains of the estimated life span of said tool.

17. Apparatus for programing. tool changes for a ma-. chine tool of the type having a tool adapted to perform .work on a workpiece and including a member operable in timed relation to and in accordance with the work performed on said workpiece comprising a scale'having means thereon designating a life span of said tool, an electrically operated mechanism including a pointerton and movable relative to said scale, said pointer being initially manually movable to a selected starting position on the scale representing the estimated life span of said tool, an electric circuit, for said mechanism, means operable by said member and controlling said sircuit-for en- I ergizing said mechanism periodically in accordance with tool operation to move saidpointer' successively and" progressively from said" starting positionandrelat'ive; to said scale, adjustable stop means, coactive with said pointer to position the same initially relativeto said scale, and'means and said scale coactive with said pointer for designating when a-predetermined'time interval in terms of machine operation remains 'of the estimated life span ofsaid tool.

18. Apparatus for programing tool changes for a ma-" ,initially manually movable to a selected. starting position on thescale representing the estimated lifespan of said tool, an electric circuit for said mechanism, means operable by said member and controllingsaid circuit for energizing said mechanism periodically in, accordance with work performed by said tool to'move said pointer successively and progressively from said startingposition and relative to said scale, and means on said scale coactive with said pointer for designating when a predetermined time interval'interms of machine operation remains of the estimated life span of said tool.

19. Apparatus for programing tool changes for a machine tool of the type having a tool adapted to perform work on a workpiece and including a member operable in timed relation to and in accordance with the work performed on said workpiece comprising a scale having means thereon designating a life span of said tool, mechanism including an indicater on and movable relative to said scale, said. indicator being movable to a selected starting position on the scale representing the estimated life span of said tool, means operable by said member for actuating said mechanism periodically in accordance with work performed by said tool to move said indicator successively and progressively from said starting position and relative to said scale, and means on said scale coactive with said [pointer] indicator for visually designating the remaining life span ofsaid' tool in terms of machine operation.

20. Apparatus for programing tool changes for a machine tool of the type having a tool adapted to perform work'on a workpiece and" including amember operable in timed relation to and in accordance with the work performed on said'workpiece comprising means for designating a life span of said tool including. an indicator movable to a selected starting position and coactive with said member periodically and successively in accordance with work performed by said tool to move successively step by step from said starting position, meanscoactive with said indicator rendered operative by said step-bystep movement thereof for designatingiwhen said life span ofsaid tool is completed, and means coactive with said indicator for visually designating the remaining life span of said tool in terms of machine operation.

21. Apparatus for programing tool changes for a mat chine tool of the type having a plurality of diflerent tools adapted to perform work on workpieces in the machine and having difier'ent spans of sharp life, said machine tool having a member operable periodically in timed relation to andin accordance with the work performed on said workpieces, said apparatus comprising means for designating the life spans of said tools and including an indicator for each different tool, means associated with each indicator having a selected visible starting position and stop position the distance between vhich represents the optimum life of the particular tool withwhich such indicator is associated; said" indicators being individually movable to said selected starting positions andbetween'said starting and stop positions, elec-' tricaliy' 'operatedmechanisms associated with said" indipositions toward and to. said stop positions, said member being operable to collectively energize said electrically operated mechanisms to simultaneously actuate said'indicators, said indicators being coactive with said member periodically and successively in accordance with work performed by said tools and said electrically operated mechanisms being operative to move said indicators successively step by step from said starting positions at a rate to cause each indicator to reach its stop position when the optimum life of the tool with which it is asso ciated has expired, means cooperative with each indicator rendered operative by said step by step movement thereof to its stop position for designating when the life span of the tool associated therewith is completed, and means coactive with said indicator for visually designating at any particular time during the operation of said apparatus the remaining life spans of said tools in terms of machine operation.

22. Apparatus for programing tool changes for a machine tool of the type having a plurality of diflcrent tools adapted to perform work on workpieces in the machine and having different spans of sharp life, said machine tool having a member operable periodically in timed relation to and in accordance with the work performed on said workpieces, said apparatus comprising means for individually designating the life spans of said tools including electrically operated devices each associated with a respective one of said tools, said devices having scales calibrated in terms of tool life and pointers independently movable on said'scales to starting positions representing the life spans of said tools; said scales having selected visible starting positions and stop positions the distance between which represent in each instance the optimum life of the particular tool with which the scale is associated, said pointers being individually manually movable to said selected starting positions and between said starting and stop positions, said electrically operated devices being associated with said pointers and operatively connected thereto move the same individually and simultaneously from said starting positions toward and to said stop positions, said member being operable'to collectively energize said devices to simultaneously actuate said pointers, said pointers being coactive with said member periodically and successively in accordance with work performed by said tools, and said electrically Y operated devices being operative topmove said pointers successively step by step from said starting positions at a rate to cause each pointer to reach its stop position when the optimum life of the tool with which it is associated has expired, means coactive with each indicator rendered operative by said step by step movement thereof to its stop position for designating when the lifespan of the tool associated therewith is completed, said pointers collectively indicating visually at any particular time during the operation of said apparatus by their positions on said scales the relative used and unused portions of the lives of all of said tools.

23. Apparatus for programming tool changes for a machine tool of the type having a plurality of different tools adapted to perform work on workpieces in the machine andhaving different spans of sharp life, said machine tool having a member operable in timed relation to and in accordance with the work performed on said workpiece, said apparatus comprising means for individually designating the life spans of said tools and including an indicator for each different tool, means associated with each indicator having a selected visible starting position and stop position the distance between which represents the optimum life ofthe particular tool with which such indicator is associated, said indicators being individually manually movable to said selected starting positions and between said starting and said stop positions, electrically operated mechanisms associated with said indicators and opera-' tively connected thereto to move the same individually and simultaneously from said starting positions toward and to said stop positions, said member being operable to collectively energize said electrically operated mechanisms to simultaneously actuate said indicators, said indicators being coactive with said member periodically and successively in accordance with work performed by said tools said electrically operated mechanisms being operative to move said indicators successively step by step fromsaid starting positions at a rate to cause each indicator to reach its stop position when the optimum life of the tool with which it is associated has expired, means coactive with each indicator rendered operative by said step by step movement thereof to its stop position for designating when the life span of the tool associated therewith is completed, means coactive with said indicators for visually designating the remaining life spans of said tools in terms of machine operation, and means cooperable with said indicators for designating and particularly identifying any and all tools having less residual life span than is required to maintain the machine in operation for a predetermined interval of time.

24. The combination as set forth in claim 20 wherein said machine tool has a plurality of different tools having difierent spans of sharp life, wherein said apparatus includes a plurality of electrically operated devices one for each difierent tool, said devices having scales calibrated in terms of tool life, wherein said indicators are pointers independently and individually movable on said scales to starting positions representing the life spans of said tools and from said starting positions to stop positions representing the ends of said life spans, wherein the first mentioned means of claim 20 includes actuator means cooperative with and rendered operable by said member for simultaneously energizing said devices periodically in accordance with work performed by said tools to move said pointers step by step from said starting positions toward and to said stop positions, said actuator means being operable to move said pointers at a rate to cause each pointer to reach its stop position when the optimum life of the tool with which it is associated has expired, and wherein said pointers collectively indicate visually at any particular time during the operation of said apparatus by their positions on said scales the relative used and unused portions of the tool lives of all of said tools.

25. The combination as set forth in claim 20 wherein said machine tool has a plurality of diflerent tools having difierent spans of sharp life, wherein said apparatus includes a plurality of electrically operated devices related to respective tools, said devices having scales calibrated in terms of tool life, wherein said indicators are pointers independently and individually movable on said scales to starting positions representing the life spans of said tools and from said starting positions to stop positions representing the ends of said life spans, wherein the first mentioned means of claim 20 includes actuator means cooperative with and rendered operable by said member for simultaneously energizing said devices periodically in accordance with work performed by said tools to move said pointers step by step from said start-.

ing positions toward and to said stop positions, said actuator means being operable to move said pointers at a rate to cause each pointer to reach its stop position when the optimum life of the tool with which it is associated has expired, wherein said pointers collectively indicate visually at any particular time during the operation of said apparatus by their positions on said scales the relative used and unused portions of the tool lives of all of said tools, and including indicator means associated with said pointers for designating and particularly identifying any and all tools having less residual life span than is required to maintain the machine in operation for a predetermined interval 0 time.

26. The combination set forth in claim 20 including means cooperable with said indicator for designating when the tool has less residual life span than is required to maintain the machine in operation for a predetermined interval of time.

27. The combination as set forth in claim 20 wherein the starting position for said indicator represents the life span of said tool and wherein said first mentioned means is an electrically operated mechanism which is energized periodically by said member to move the indicator from said starting position.

28. The combination as set forth in claim 20 wherein said first mentioned means includes a scale which represents a life span of the tool and an electrically operated mechanism for moving the indicator from a starting position on the scale representing a life span of the tool to a stop position representing the end of said life span, and wherein said electrically operated mechanism is energized periodically by operation of said member to move said indicator.

29. The combination as set forth in claim 20 wherein said first mentioned means includes a scale which represents a life span of the tool and electrically operated mechanism for moving the indicator from a starting position on the scale representing a life span of the tool to a stop position representing the end of said life span, wherein said electrically operated mechanism is energized periodically by operation of said member to move said indicator, and including means for designating when there is less residual life span than is required to maintain the machine in operation for a predetermined interval of time.

30. The combination as set forth in claim 19 including means coactive with said indicator for designating when a predetermined time interval in terms of machine operation remains of the estimated life span of the tool.

References Cited in the file of this patent or the original patent UNITED STATES PATENTS