US2270590A - Honing machine - Google Patents

Description

- Jan. 20, 1942. A OHNSON 2,210,590

HONING MACHINE Filed Oct. 10, 1938 5 Sheets-Sheet l 38' 2 m4 y HA 1/ J2 T 0000 ENVENTQQ.

/1 Hoary s Jan. 20, 1942. A. M. JOHNSON I 2,270,590

HONING MACHINE Filed Oct. 10, 1938 5 Sheets-Sheet (5 m Q4/022 'Q/o/mscbn 59m 45AM 5 Sheets-Sheet 4 NVESN'TOZL/ Qrzcfo/v AI :1 P, I. i

A. M. JOHNSON HONING MACHINE Filed Oct. 10, 1938 Jam 20, 1942.

Jan. 20, 1942. A, M JOHNSQN 2,270,590

HONING MACHINE Filed Oct. 10, 1958 5 Sheets-Sheet 5 Patented Jan. 20, 1 942.

HONING MACHINE Albert M. Johnson, Rockford, 111., asslgnor to Barnes Drill (30., Rockford, 111., a corporation or v Illinois Application October 10, 1 938, Serial No. 234,146

23 Claims.

The invention relates to the art of dressing cylindrical surfaces, and more particularly to an improved method of and machine for honing such surfaces to a true contour and smooth finish.

The honing of cylindrical work pieces to exact dimensions and with an extremely smooth, accurate surface finish is ordinarily carried out in several steps such as a rough honing step and a finish honing step. For rough honing, the tool is equipped with relatively coarse abrasive stones adapted forthe removal of a substantial amount of metal-so that the major surface irregularities may be removed and the work reduced approximately to the desired size in a minimum of time. The finish honing step is performed by a tool equipped with finer abrasive stones which remove the remainder of the stock, usually only a small amount, and leave the surface with an extremely smooth finish.

Due to their difierent operating characteristics, rough and finish honing tools have widely differing operating requirements. For this reason,

it has heretofore been the practice to perform the rough and finish honing operations on separate machines, or, in cases where only one machine is available, to rough hone the entire lot of work pieces, change the tool and reset the machine for finish honing. In either case, considerable manual handling of the work is involved such as transferring work from one machine to the other or setting it up twice on the same machine.

The principal object of the present invention is to increase productive capacity by substantially reducing the amount of manual handling of the work required for rough and finish honing. To this end, the invention provides a novel method of honing wherein honing tools having different abrasive capacities are rotated at the same speed and reciprocated through the same number of strokes while the pressure exerted by the respective tools on the work is varied in accordance with their respective metal removing or abrasive capacities. In this way, a proportionate share of the work to be done is properly allocated to each of the tools so that the entire finishing operation can be performed in a singlemachine without intermediate handling of the work.

Another object is to providea novel honing machine adapted to rough and finish hone cylindrical work pieces in accordance with the improved honing method.

the pressure exerted on the work pieces by the honing tools carried on the several spindles.

Another object is to provide an improved honing machine particularly suitable for mass production methods.

Another object is to provide an improved work clamping means for use in connection with an indexing work support, which clamping means is operative to hold the work securely in position during metal removing operation, such as honing or lapping, without subjecting the work support to excessive strains.

Another object is to provide a honing machine having control means of novel and advantageous character for controlling and coordinating the operation of tool actuating means, work indexing means and work clamping means to insure oper-' ation of these elements invariably in proper timed relation.

A further object is to provide an improved honing machine embodying novel toolactuating means and controls therefor, whereby withdrawal of the tool from the work is delayed until the tool has been contracted or collapsed sufiiciently to insure against injury either to the tool or work incident to such withdrawal.

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment illusthe line 3-3 of Fig. 2 showing details of the mechanism for indexing the work support.

Fig. 4 is a plan view of the work support with the tool guiding and clamping fixture broken away to show the relative positions of the work holding fixtures.

Fig. 5 is a diagrammatic view showing the relationship of the various machine elements and the hydraulic circuits and actuating means for the machine.

Fig. 6 is a schematic diagram of the electrical control system of the machine.

The improved method of honing may be carried out with various types of honing or lapping machines for dressing either internal or external cylindrical surfaces. For purposes of illustration, I have herein disclosed a vertical honing machine for operating on internal cylindrical surfaces wherein the tool is rotated and reciprocated while the work is held stationary. It is stationary.

to be understood, however, that the invention is not limited to the particular form or environment shown but embraces all modifications, adaptations and alternative constructions falling within the spirit and scope of the appended claims.

Referring now to Fig. 1 of the drawings, the lilustrative machine comprises generally a hollow base 8 from which rises an upright frame structure or column 9. A pair of guide bars l0 mounted on the face of the column in parallel spaced relation constitute a guideway for a multiple spindle reciprocatory tool head H which, in the present instance, is adapted to be supported on the guide bars by a spool-shaped roller bearing l2 as shown in Fig. 4.

.The illustrative machine is of the two-station type. that is, it is adapted to operate on two separate work pieces simultaneously. The machine accordingly is provided with two working stations and a loading and unloading station, while the head is equipped with two spindles, that is, one at each working station. As herein shown, the head is equipped'with a spindle l3 at the first working station and a similar spindle ll at the second working station. In case it is desired to perform more than two operations at a time or to perform similar operations on more than one work piece at a time, additional tool spindles may be provided as required.

Floatingly mounted on the lower ends of the tool spindles l3 and I4 are honing tools i5 and I5 of well known construction each comprising a series of elongated abrasive'elements arranged around a cylindrical holder for radial movement into or out of engagement with the surface of a work piece. The honing tool l5 carried by the spindle [3 at the first working station to which work pieces are initially presented may be conveniently equipped with relatively coarse abra- 4 sive elements adapted for the removal of a substantial amount of metal as is desirable in rough honing, while the honing tool l5 carried by the spindle I4 is equipped with finer abrasive stones adapted for the removal of a smaller amount of metal but capable of producing a smooth finish necessary for finish honing.

In the honing operation. the: abrasive elements of the tool are rubbed over the surface of the work piece with simultaneous rotational and reciprocatory movements, the abrasive elements of the tool being shifted radially outwardly or expanded so as to exert a substantial pressure on the surface being operated on. In dressing external cylindrical surfaces, the abrasive elements of the tool will be shifted'radially inwardly or contracted,. as is well understood in the art. It will be understood further that the "rotational and reciprocatory movements of the tool and work are relative and may be efiected 00 by movement of either the tool or the work. In

the machine illustrated, the tools are rotated and reciprocated while the work pieces are held The means provided for effecting I such rotation and reciprocation are arranged to be hydraulically actuated, although any other suitable power actuating means may be employed as desired. It is also preferred to employ hydraulic actuating means for expanding the tools in order to insure uniform pressure of the abrasive stones onthe work throughout the 'honing operation.

r The means for rotating thehoning tools, as

' herein' shown, comprises a rotary hydraulic motor I6 drivingly connected with the tool 5 m- 7' dies 13 and I4 by a splined drive shaft I1 and suitable gearing enclosed in the column 8 and head II, as shown diagrammatically in Fig. 5. The motor is preferably of the variable speed type so that the rotational speed of the tools may be synchronized with their reciprocatory speeds as required to provide any desired crosshatch finish. Pressure-fluid is supplied to the spindle driving motor l6 by, a, pump 2i. which draws the fluid from a reservoir or sump 22 and delivers it through suitable hydraulic circuits including a reversing valve V-I operable to either of two positions to govern the direction of rotation of the motor and thus the direction of rotation of the honing tools. The valve V--l is arranged to be operated to its alternating positions by solenoids VSI and VS-l' under control of an electrical control system to be described hereinafter. An electric motor 22* drives the pump 2| continuously while the machine is in operation.

Reciprocation of the head II and the honing tools carried thereby is effected by a piston 23 connected with the head by a piston rod 24.

The piston 23 is arranged to operate in a cylinder 25 rigidly supported in a vertical positionon the upper end of the column 9'. Pressure fluid is supplied to the cylinder 25 by a pump 26 driven by an electric motor 21. Interposed between the pump and the cylinder is a stop valve V--2 and a reversing valve V3. Valve V--2 is preferably spring-biased to a stop position in which pressure fluid is shut off from the cylinder 25. Operation of the valve to open position for initiating reciprocation of the tool head is effected by a valve operating solenoid VS2.

The reversing valve V3, which controls the supply of pressure fluid to the upper and lower ends of the cylinder 25 alternately to reciprocate the piston 23, is preferably arranged for hydraulic operation under control of a pilot valve PV. Ifhe pilot valve in turn is operated in well known manner by means ,of a control rod 28 adapted to be shifted at each end of the tool stroke by a stop arm 29 on the head. The stop arm is positioned for engagement with upper and lower limit stops 30 and an intermediate stop 3| on the control rod. The lower stop 30, together with the intermediate stop 3|, normally cooperate to confine the movement of the head within a predetermined range of travel, thus defining the working stroke of the tool. The upper limit stop defines the uppermost limit of movement of the head.

In order to dissociate the tool and the work,

apull-out solenoid PS is arranged to rock the control rod '28 about its axis so as to move the intermediate stop 3| out of the path of the arm 29 whereby the head may move beyond its normal range of travel and withdraw the tools from the work pieces. Control of the various valve operating solenoids and the pull-out solenoid is effected by suitable electrical switches and relays incorporated in the control system to be described hereinafter.

Expansion and contraction of the tools l5 and I5 is eflected by means of pistons 32 and 32 operating in cylinders 33 and 33 carried on the F acts.

Movement of the pistons to the lower end of their cylinders operates the actuating mechanism to expand the abrasive elements into engagement with the surface of the work piece.

Movements of the pistons 32 and 32 for expanding and contracting the tools is effected by means of pressure fluid supplied thereto through a reversing valve V--4. With the valve in the position shown, pressure fluid is supplied by way of a telescoping connection indicated generally at 35 to the lower ends of both cylinders. A solenoid VS-4 is arranged to operate the valve to its alternate position in which pressure fluid is supplied by way of a telescoping connection 36 to the upper ends of the cylinders.

To provide for regulating or varying the pressure exerted by the tools on the respective work pieces in accordance with the metal removing or abrasive capacity of the tools, cylinders 33 and 33 are equipped with an individual pressure control valve 3'! and 3'! by which the pressure exerted by the associated tool upon the work piece may be controlled independently. This permits accurate adjustment of the tool pressure in accordance with the particular type of tool employed so that each of the tools may be adjusted to remove the desired amount of metal in the same number of strokes. In other words. the tools being reciprocated by a common head are thus enabled to perform different types of operations efli-ciently and accurately and without danger of either tool removing too much or. too little metal from the work piece upon which it Suitable pressure gauges 38 and 38 may be provided for indicating the pressure applied to the respective tools to facilitate adjustment of the same.

It has been found desirable to expand the tools with relatively light pressure during the initial stages of the honing operation and to,increase the pressure substantially as the honing .proceeds so that the tool marks left by the preceding operation may be removed without danger of overloading or damaging the 'tool. Means is accordingly provided for supplying pressure fluid to the tool actuating means from two separate sources under the control of a suitable valve V5. In the present instance, low pressure fluid is supplied by the pump 26 while high pressure fluid is supplied by the pump 2|. The solenoid V5 is operated by a solenoid VS5 to determine the particular source employed. Energization and deenergization of the solenoid is effected automatically under control of a timing device incorporated in the electrical control circuit.

While any suitable means may be utilized for holding the work in operative relation to the tools, the present machine embodies an indexingwork support for carrying the work between the various stations, together with automatically controlled power actuated clamping'means for clamping the work securely in place during the honing operation. To this end, there is mounted on the base 8 immediately below the head II a work supporting and clamping mechanism indicated generally by the reference character 4| (Figs. 1 and 2). The supporting mechanism includes generally a circular table 42 rigidly supported on the upper end of the vertically disposed shaft 43 which is journaled at its lower end on a sub-base 44 suitably secured to the base 8. The shaft 43 and table 42 are adapted to be indexed, that is, rotated step by step, to

carry work pieces into position to be operated on by the tools l5 and I5.

As shown in Figs. 1 and 4, the table is equipped with three work holders 46 appropriately shaped to hold the work pieces 45. The work holders are spaced apart around the table similar to the spacing of the spindles l3 and I4 in the head. Accordingly, when the table is in a set position, one work holder is disposed at the first working station, that is, below the tool i5, the adjacent work holder is at the second working station or below the tool I5 and the third work holder is at the loading and unloading station where it is clear of the tools and clamping mechanism so that the work pieces may be conveniently loaded thereon or removed therefrom.

Rotation of the table through one step advances the first work holder tow the second working station and the newly loaded third work holder to the first station at which the rough and finish honing operations may be performed.

The second work holder is advanced to the loading and unloading station at which the finished work piece may be removed and a new work piece set in place to be operated on in the succeeding cycle of the machine. pieces are fed through the machine in succession and two work pieces are operated on simultaneously in each machine cycle, one piece being rough honed at the first station and the other piece being finish honed at the second station.

The means for indexing the table 42, as herein shown, includes a piston 5| (Fig. 5) operating in a horizontally disposed cylinder 52 located at one side of the sub-base 44. A piston rod 53 projects forwardly from the cylinder and is formed with rack teeth 54 (Fig. 3) meshing with the teeth of a ring'gear 55 which encircles a diskshaped enlargement 56 rigid with the lower end of the table supporting shaft 43. Forward and return movements of the piston thus serve to oscillate the gear 55 through an angle of approximatel'y 120.

Movements of the gear in one direction-are utilized to advance or index the table 42. For this purpose the gear is operatively connected with the enlargementi56 through the medium of a one-way driving connection provided by a latch member in the form of a lever 51 pivoted intermediate its ends-in a circumferential slot 58 in the gear 55. The forward end of the latch is formed with an inwardly projecting lug 59 adapted to enter suitable notches 60' in the periphery of the member 56. Three notches 60 are provided in the present instance, these notches being spaced circumferentially around the member in the same relative positions as the several work holders sothat the holders willv be properly positioned with respect to the tools when the ring member is advanced through a full step by forward movement of the piston 5|.

The lug 59 is yieldably held in the notch60 by a spring 6| which acts on the forward end'of the lever 51, thus completing the driving connection between the ring gear 55 and member 56. In order to permit return movement of the ring gear while the table remains in advanced position, the driving connection is interrupted at the end of the indexing stroke. To this end, a plunger 62 is positioned for engagement with the rear end of the lever 51 when the ring gear is fully advanced by the forward movement of the piston 5|. As herein shown, the plunger 62 is slidably supported in a suitable bearing in the sub-base 44 for movement toward and from the In this way, the work pinion 12 fast on the shaft 65.

. proper point-in the machine cycle, is advanced through the medium of a link 63 connected with a crank arm 64 fast on a rock shaft 65 Journaled on a bracket 86 secured to one side of the sub-base 44. The shaft 65 is arranged to be rocked periodically by a piston 61 operating in a cylinder 68 (Fig. 5). Projecting forwardly from the piston 61 is a piston rod 68 (Fig. 2) which is formed with a cylindrical enlargement 18 having rack teeth 1| meshing with the teeth of a The forward movement of the piston 61 thus acts to rock the shaft 65 in a clockwise direction, as viewed in Fig. 2, and the plunger 62 is thus moved forwardly to engage the rear end of the lever 51 and rock the lever against the action of the spring 6| to withdraw the lug 58 from the notch 68. The lever is held disengaged until the ring gear 55 is turned back sufficiently to prevent the lug 58 from again entering the notch 68. The lug then rides overthe surface of the member 56 until the return stroke of the piston is completed, at which time the lug drops into the next notch 68 of the member. The mechanism is now in condition to advance the shaft 43 and table tion of the piston 5|.

In orderto avoid any possibility of rearward movement of the table due to friction of the parts, and to accurately locate the work pieces with respect to th tools, means is provided for locking the work supporting mechanism in set position during the honing operation. To this end, the cylindrical member 18 on the piston rod 68 is formed with a forwardly projecting element 13 constituting a locking pin which is adapted toenter suitable locking recesses 14 formed in a hub 15 rigid with the shaft 43. Referring to Fig. 2, it will be observed that the end of the looking pin is tapered and the recess 14 is fitted with a correspondingly tapered bushing 16. The pin and bushing thus coact to shift the support in either direction as required to accurately position the work relative to the tools. The locking pin also serves to hold the table rigidly against movement during the return movement of the ring gear 55 and while th honing operation is being carried out. Since the locking pin 14 is operated by the. piston 61 which also operates .the unlatching plunger 82, it'will be apparent that the work table will be locked simultaneously with the withdrawal of the latch 51, thus insuring against any movement of the table on the return stroke of the indexing piston.

The work clamping mechanism in-the present instance is' entirely independent of the work table, thus enabling the work to be clamped rigidly in place without subjecting the table to excessive strains. herein shown is carried on a slid 8| mounted on a dove-tailed slideway 82 formed on the face of the column. 8 so that the entire mechanism may be adjusted relative to the work table to accommodate different classes ofwork. Rigid with the slide 8| is a forwardly projecting bracket having a central hub portion 82 from opposite sides of which project horizontally disposed brackets 83. The hub portion 82 is formed with a vertical bore 84 constituting an upper bearing for th table supporting shaft 43.

Bolted or otherwise secured to the brackets 83 is a generally U-shaped bridging member 86 extending over the work table 42. The member 86 42 another step in response to the next opera- I is apertured at each work station, and in each 'on the work table, the work piece is lifted from the holder 46 and clamped against the work engaging elements 88.by suitable power actuated means. Lifting and clamping means is provided at each working station. This means, as herein shown, comprises a piston 8| operating in a vertically disposed cylinder 82 secured to the underside of the bracket 83 belowv each fixture 81.

The piston has a piston rod 88 which projectsthrough the bracket .83 and at its upper and carries a work engaging pad 84 adapted to engage the lower end of the work piece 45 which extends through an aperture in the work table as shown in Fig. 2. When pressure fluid is introduced into the lower end of the cylinder 82, the piston 8| is moved upwardly and lifts the work piece off of the holder 46 and into engagev ment with the blocks 88 of the work clamping The clamping mechanism as fixture, thus holding it independently of the table 42.

A sheet metal pan or casing mounted on the brackets 88 encircles the work table 42 and serves as a temporary reservoir for the coolant which is directed over the tools in well known manner during the honing operation. The casing is provided with a central aperture for theshaft 43 and suitable apertures for the piston rods 83. These apertures are formed with-upwardly extending flanges 86 to prevent leakage -of coolant. The pads 84 are also formed with downwardly extending flanges 81 to prevent the coolant from splashing over the flanges 86 encircling the piston rod apertures. As shown in Fjig. 1, drain pipes 88' extend from the casing 85 to a suitable coolant reservoir within the base 8 whereby the coolant is returned to the reservoir for filtering and storage.

Pressure fluid is supplied to the indeidng cylinder 52 and the work clamping cylinders" by a pump 88 (Fig. 5) driven in tandem with the pump 26 by the motor 21. ferred to are connected with the pump by a hydraulic circuit in which are interposed suitable valves including a main control valve V-6, pressure actuated valves PV--|, PV-2 and PV-8,

and check valves CV-l, (JV- 2, (IV-8 and CV---4. These valves are arranged in the circuit in such manner as to effect operation of the indexing and clamping mechanisms in predetermined sequence.

The operation of the indexing and clamping control system will be most readily understood when considered in connection with the operation of the electrical control system shown in Fig. 6, which governs the cyclic operation of the entire machine. This latter system is arranged to initiate the operation of the various machine elements in proper timed relation in response to the actuation of a single manually operable cycle starting switch, Before the operating cycle is initiated, the pump motor 21 is started by momentary closure of a push button switch S-| which completes an energizing circuit for a relay R--|. The relay closes a holding switch R-l I to The cylinders recomplete a holding circuit for itself by way normally closed, manually operable stop switch S2. The relay R-l also closes a switch R-IZ to connect the motor 21 across the line conductors L-l, L2 and L3 over which electric power is supplied to the machine.

With the motor 21 running, pressure fluid is available for operating the indexing and clamping mechanisms and the tool reciprocating mechanism. Assuming for the purpose of illustration that the machine has just completed an operating cycle, the various machine elements and control valves will be in the positions shown in Fig. 5. A new work piece is now placed on the work holder at the loading station and the machine is ready for the next operating cycle.

The operating cycle is started by momentary closure of a manually operable start switch 8-3 which completes an energizing circuit for a starting relay R2. Therelay closes switch R-ZI, thereby completing a holding circuit for itself by way of a normally closed stop switch 8-4. A parallel circuit is closed for the valve operating solenoid VS-6 which operates the valve V to its alternate position, thereby directing pressure fluid through the pressure operated valve PV-I to the upper ends of the cylinders 92. The pistons 9| move downwardly to unclamp the work pieces and deposit them on the work holders 46 at the first and second working stations. Spent pressure fluid from the lower ends of the cylinders 92 is returned to the sump' 22 by way of the check valve CV|. When the pistons 9| reach the ends of their strokes, pressure builds up in the system until the valve PV-l opens and admits pressure fluid to the inner end of the locking cylinder 68. This shifts the piston 61 outwardly, withdrawing the pin 13 to unlock the work table and at the same time withdrawing the latch operating plunger 52 (Fig. 2).

As the piston 61 approaches the end of its stroke, it uncovers a port in the cylinder 68 which permits pressure fluid to flow into the outer end of the indexing cylinder 52. The piston 5| accordingly executes its indexing stroke, that is, it moves inwardly, and through the medium of a piston rod 53, ring gear 55, and the one-way driving connection hereinbefore described, it advances the work table one step. Spent pressure fluid from the inner end of the cylinder 52 is discharged through an unrestricted port 99 until the piston covers that port as it approaches the end of its stroke. Thereafter, pressure fluid is discharged through a port 99 and a control valve RV which has an adjustable restricted opening. The valve RV restricts the flow of pressure fluid from the cylinder, thus slowing down the movement of the piston so that the work table may be brought to a stop without shock or ar.

When the piston 5| reaches the end of its stroke upon completion of the indexing operation, the piston rod 53 operates a switch 8-4 which opens the holding circuit of the relay R,2,

The relay in turn opens the circuit of the solenoid VS-Ii which permits the plunger of .the valve V-6 to return to normal position. Pressure fluid is now directed into the outer end of the locking cylinder 68 moving the piston 61 inwardly and thereby advancing the locking pin I3 into table locking position. This movement of the piston is also operative to advance the plunger 52 and interrupts-the driving connection between the ring gear 55 and the table supporting mechanism as hereinbefore described.

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As the piston 61 approaches the end of its inward stroke, it uncovers a port which admits pressure fluid to the pressure controlled valves PV-2 and PV-3. Valve PV3 is set to open when the pressure builds up to a predetermined point and, on opening, admits pressure fluid to the lower ends of the clamping cylinders 92. The pistons 9| are therefore moved upwardly to clamp the work pieces against the fixtures 8| carried on the stationary clamping member 86. After the pistons complete their clamping strokes, pressure in the hydraulic system builds up further until it is sufl'lcient to operate the valve PV2 which directs the fluid into the inner end of the indexing cylinder 52. In this instance, the restricted opening valve is by-passed, the fluid entering the cylinder by way of the check valve CV-Z and theport 99 so that the return movement of the indexing piston is efiected without delay. Spent pressure fluid is exhausted from the outer end of the cylinder 52 byway of a check valve CV-3 which by-passes the cylinder 68 through which pressure fluid was supplied to the cylinder. in the initial portion of the cycle.

As a result of the operationof the indexing and clamping mechanism above described, new work pieces are presented in operative relation to the honing tools I5 and I5 and the honing operation may now be initiated. This operation is started automatically incident to the return movement of the indexing piston 53. To this end, the piston rod 53 is formed with a notch I00 (Fig. 5) arranged to engage an operating member IIII of a starting switch S -5. The switch 8-5 is closed momentarily and completes an energizing circuit for a relay R-3. The relay in turn closes switch R--3I to energize the valve solenoid VS-2. As previously explained, the solenoid VS-'2 operates the valve V2 to start the reciprocation of the tool head I I.

As the tool head begins its downward move-' ment, it closes a maintaining switch S6 by means of a cam I02. This switch is interposed in a holding circuit for the relay R-3 and serves to maintain the relay R3 energized and thus continue the supply of pressure fluid to the reciprocating mechanism. A normally closed, manually operable stop switch S'| is connected in series with the switch S--5 so that reciprocation of the tool head may be interrupted at any time if desired. Further, a normally open, manual I operable switch 8-8 is connected in shunt of the switches S-5 and S6 so that reciprocation of the tool head may be initiated independently of the indexing mechanism when the machine is being set up or adjusted.

The tool head I I continues its downward movement and carries the tools I5 and l5 into the work pieces. As the tools enter the work, a cam I03 on the head closes a switch 8-9 which completes circuits for a spindle motor starting relay R-4, a tool expanding relay R--5 and an electrically driven timing device TM-I. The relay R-l ,opens switch R-H and closes switch R42. .Switch R-4I opens the starting circuit for the relay R2 so that the relay cannot be energized to start the indexing mechanism while the tools are operating on the work. Switch R-42 completes a circuit for a relay R-Ii which closes switch R-Iil to connect the motor 422 Relay R-5, onenergizing in response to the closure of the switch -8, closes a switch R- 5l to energize the valve operating solenoid VS-l. The solenoid operates the reversing valve V4 whereby pressure fluid is directed into the upper end of the tool expanding cylinders 33 and 33. Pressure fluid supplied to the cylinders at this time is derived from the low pressure pump 26, and accordingly the tools exert a relatively light pressure on the work.

As the tool head approaches the lower limit of its working stroke, the stop arm 29 engages the lower limit stop 30, and through the control rod 28 and pilot valve PV, operates the valve V-3 and reverses the direction of movement of the head. At the upper end of the working stroke, the stop arm engages the intermediate stop 3| and again reverses the position of the valve V-3. This sequence of operation is repeated and the tool head is thus reciprocated through its normal range or working stroke in which the tools are traversed over the surfaces of the respective work pieces.

The timer TM-l which is started in operation simultaneously with the expansion of .the tools,

may be of any suitable type. As herein shown, it is arranged to be driven by a relatively small electric motor shown diagrammatically as comprising an armature A and field winding W. The timer is arranged to close switches TM-ll and TM-i2 after a predetermined time. Closure of the switch TM-ll energizes the solenoid VS-i which operates the valve V-5 to switch over the tool expanding mechanism from the low pressure pump 26 tothe high pressure pump 2|. The pressure exerted by the tools on the work is therefore increased to its maximum so that the tools may operate with greater eiiiciency. It will be understood that the timer TMI is adjustable so that the time required for the switches to close may be varied as required to permit the tools to remove the most prominent surface irregularities from thework before they are expanded with full pressure.

The closure of the switch I'M-l2 starts a second timer I'M-2 provided for timing the honing operation. This timer is likewise adjustable so that the length of the honing operation can be varied as required for diiferent classes of work. At the end of the predetermined time for which the timer is set, it closes a switch TM-2l to complete a circuit for a relay R-I which opens its switch R-Il to deenergize relay R-S and thus initiate the collapse of the tools l5 and I5. Such collapse is brought about by the deenergization of the solenoid VS-l which permits the reversing valve V-4 to return to normal position and direct pressure fluid into the lower ends of the cylinders 33 and 33'".

Relay R.--I also closes a switch R-IZ to start a third timer TM3 which may be ,similar to the timer TM-l above described. This timer is arranged to modify the action of the reciprocation controlling mechanism whereby to effect movement of the tool support or headll beyond its normal range of travel in the working stroke and thus dissociate the toolsfi-om the work. The timer is set to allow sufficient time for the collapse of the tools before the tools are withdrawn from the work. This is to guard against iniury to the tool or work incident to such withdrawal. v

The withdrawal of the tools is eflected by closure of the timer switch TM-3| which completes a circuit for a pull-out relay 3-. The relay,

by closing its switch R-Ol, energizes the pullout solenoid PS. As explained hereinbefore, the solenoid rocks the control rodto move the intermediate stop 3| out of the path of the stop arm 29 so that the head II is permitted to move to its uppermost positionand withdraw the tools from the work. Since the tools are collapsed at this time, any possibility of injury to the tools or work is effectually avoided. When the head reaches its upper limit position, the machine cycle is terminated by the opening of the cam operated switch S6.

The control system also includes means whereby the direction of rotation of the tools may be controlled either automatically or manually.

. The automatic or manual character of the control is determined by the position of a manually operable switch Sl 2. Whenthe switch is operated to its upper position, it connects up an electrically operated timing device TM-4 which is arranged to periodically open and close a switch TM-ll.

plunger of the valve V l to the right end of the valve casing, as shown in Fig. 5, thereby causing the motor It to rotate the tools in one direction. Upon closure of the switch TM-ll, a relay R-ii is energized and the relay interrupts the energizing circuit of the solenoid VS-I' by opening its switch R-Ql. At the same time, the relay closes switch R-M, thereby energizing the solenoid VS-IA which operates the valve V-l to its alternate position and reverses the direction of rotation of the motor It.

The timer TM--4 may be rendered inactive and the relay R 9 placed under manual control by shifting the switch Sl2 to its lower position. Under these conditions, closure of a normally open switch S--l3 energizes the relay R-l with the results above described. The relay when energized locks by way of its switch R-93 and a normally closed switch S-IL. Opening of the switch Sl4 deenergizes the relay and reverses the direction of rotation of the spindle driving motor as above described.

It will be apparent from the foregoing that the invention provides an improved method of rough and finish honing cylindrical work pieces. In carrying out the improved method, the rough and finish hones are rotated at the same speed and reciprocated through the same number of strokes while the pressure exerted by the tools on the work is variedin accordance with their respective abrasive capacities so that a proporiusted independently to allocate the proper share of work to each tool and to insure each tool iinishes its operation at the same time. Moreover, the honing operation is terminated automatically by the collapse of the tools after a predetermined operating time and the tools are withdrawn from the work. Such withdrawal of the tools isdelayed, however, until the tools are col- When the switch TM-ll isopen, solenoid VS-'-l is energized and shifts the indexing the same to carry the work pieces into operative relationwith the tools successively. Clamping means of novel and improved construction cooperating with the indexing mechanism operates to hold the work securely during the honing operation without placing excessive strains on the supporting mechanism. Automatic controls are provided for the above mechanism and these controls are interlocked in a novel manner with the controls of other elements of the machine to insure operation of all of the machine elements in proper timed relation.

, I claim as my invention:

1. In a machine for rough honing and finish honing cylindrical work pieces in successive steps, in combination, a reciprocatory head, two tool supporting spindles journaled onsaid head, means for rotating the spindles, an expansible honing tool supported on each spindle and rotatable therewith, one of said tools being adapted for the removal of a substantial amount of metal from a work piece and the other tool being adapted for the removal of a smaller amount of metal but capable of producing a smooth -finish on the work piece, hydraulically actuated means associated with each tool for expanding the tool -into operative engagement with a work piece, a

support for work pieces to be operated on by said tools, a hydraulic circuit for supplying pressure fluid to the tool expanding means to expand the tools into operative engagement with the work pieces, and control means in said circuit individual to each tool for independently varying the pressure exerted by the tool on the work piece.

2. In a machine for rough honing and finish honing cylindrical work pieces in successive steps, in combination, a reciprocatory head, a,

means operative to confine the reciprocatory movements of the tool to a normal range of travel for a predetermined time wherein the tool is traversed over the work, a control device efiective after said predetermined time for initiating the operation of said tool actuating means to collapse the tool, and a second control device'initiated in operation by said first device operative after a predetermined interval to modify the action of said control means whereby to effect movement of the tool beyond said normal range of travel and out of engagement with the work. a Y

4. In a honing machine, in combination, an expansible honing tool, means for supporting work to be operated on by said tool, power actuated means for expanding and collapsing the tool, a motor for rotating the tool, hydraulically actuated means for reciprocating the tool, control means for said hydraulically actuated means operative to confine the reciprocatory movements of the tool to a normal range of travel wherein the tool is traversed over the work on said support, a timing device operative to control said tool actuating means and efi'ect the collapse of the tool after a predetermined period of reciprocation within said normal range of travel, and a second timing device operative to modify the action of said control means and effect movement of the tool beyond said normal range of travel a predetermined time after the collapse of the tool whereby thetool is withdrawn from the work in a collapsed condition.

5. In a honing -machine,'in combination, a work support, a tool support, a honing tool carried by the tool support, actuating means for expanding and collapsing said tool thereby rentime wherein the tool is traversed over the work pair of tool supporting spindles journaled on said head, means for rotating the spindles, an expansible honing tool supported on each spindle and'rotatable therewith, one of said tools being adapted for the removal of a substantial amount of metal from a work piece and the other tool being adapted for the removal of a smaller amount of metal but capable of producing a smooth finish on the work piece, a support for work pieces to be operated on by said tools, hydraulically actuated means for expanding the tools into engagement with the work pieces including a cylinder and piston individual to each tool, a hydrauliccircuit having a branch extending to each cylinder for supplying pressure fluid to the cylinder for expanding the associated tool, and a pressure control valve in each branch for independently regulating the pressure with which the associated tool is expanded against the work piece.

3. Ina honing machine, in combination, an

expansible honing tool, means for supporting and to thereafter effect movement of the same beyond said normal range to dissociate the tool from the work, and means operative to delay the dissociation of the tool from the work until the tool is collapsed and thereby prevent injury to the tool or work incident to such dissociation.

6. In a honing machine, in combination, a horizontally disposed work support, a tool head mounted above said work supp rt for movement toward and from the same, a honing tool carriediby the-head, work clamping means comprising a stationary member disposed between said head and said support, hydraulic cylinder and piston means disposed below the work supried by the head, work clamping means com--- prising a stationary member disposed between said head and said support, power actuated means disposed below said work support including a member adapted to engage a work piece on said support and clamp the same'against said stationary member, and means carried by said stationary member for guiding the tool into the work piece.

8. In a honing machine, in combination, a honing tool, power actuated means for rotating and reciprocating said tool, a movable work support, means for moving said work support step by step to carry work pieces into position to be operated on by said tool, means for holding the work piece independently of said support while the tool is operating thereon, said holding means comprising a stationary member extending over the work support, a clamping member disposed below the work support substantially in alinement with the tool and work piece to be operated on, and power actuated means for operating said clamping member to clamp the work piece against said stationary member.

9. In a honing machine, in combination, a honing tool, power actuated means-for rotating and reciprocating" said tool, a movable work support,-means for moving said work support step rotating and reciprocating the tool, a movable work support, power actuated indexing means for moving said support intermittently to carry a work piece into position to be operated on by the tool, power actuated work clamping means including a rigid member located above the work support and a cooperating member located below the work support for holding the work independently of the support while the tool is operating thereon, and a combined electrical and hydraulic control system for controlling the cyclic operation of the machine, said control system being operative to initiate operation of the power actuated indexing and clamping means in predetermined timed relation to the operation of the tool rotating and reciprocating means, and a manually operable electrical switch in the control system operative when actuated to start the operating cycle.

by step to carry work pieces into position to be operated on by said tool, means for holding a work piece while the tool is operating thereon comprising a stationary member extending over the work support, a clamping member disposed below the work support substantially in aline-' ment with the tool and workpiece to be operated on, and hydraulically actuated means for' operating said clamping member to clamp the work piece against said stationary member independently of said work support.

10. In a honing machine, in combination, a-

' ently of the table while the tool is operating thereon, and means supporting said members for adjustment relative to the table to accommodate work pieces of diiferent sizes.

11. In a honing machine, in combination, a

I. honing tool, power actuated means for rotating and reciprocating said tool, a movable work supporting table, means for moving said table step by step to carry work pieces into position to be operated on by said tool, power actuated clamping means including members disposed on opposite sides of the table operative to ,hold a work piece independently of the table while the tool is operating thereon, and control means for initiating the successive operation of the table moving means, the work clamping means and the tool rotating and reciprocating means.

12. In a honing machine, in combination, a honing tool, power actuated means for rotating and reciprocating said tool, a movable work support, means for moving said work support step' by step to carry work pieces into position to be operated on by said tool, power actuated clamping means including a-stationary member mounted above the work support and movable members located below the work support-for holding the work independently of the work support while the tool is operating thereon, and a control system for initiating the operation of the diflerent elements of the machine in proper timed relation in each machine cycle and for stopping the machine upon completion of the cycle.

13. In a honing machine, in. combination, a honing tool, separate power actuated means for 14. In a honing machine, in combination, a

tool support an expansible honing tool carried by said support, means for supporting work to be operated on by said tool, means for actuating said tool support to move the tool into operative relation to the work, a motor for rotating the tool, hydraulically actuatedmeans for expanding the tool into engagement with the work,

valve means for said hydraulically actuatedv means operative to vary the pressure exerted by the tool on the work, a timing device for said valve means, and control means actuated by said tool support incident to the' movement ofv the tool into operative engagementwith the work for initiating the operation of said tool rotating motor, said hydraulic means and said timing device.

15. The method of rough and finish honing cylindrical surfaces which comprises arranging two pieces of work respectively intended for rough and finish honing on a work support in spaced relation according to the spacing of two honing tools on a tool support having honing stones, of difierent abrasive capacities respectively, producing a predetermined number of relative reciprocations between the two supports, effecting relative rotation between thetools and the work uniformly during such relative reciprocations, and pressing the honing stones of the respective tools against their work pieces variably according to the abrasive capacities of the tools? 16. The method of rough and finish honing cylindrical surfaces which comprises arranging two pieces of workrespectively intended for v rough and finish honing on a work support in spaced relation according to the spacing of two honing tools on a 'tool support having honing stones of different abrasive capacities respectively, producinga predetermined number of relative reciprocations between the two supports, effecting relative rotation between the tools and the work in-synchronism with such relative reciprocations, and pressing the honing stones of I moval of a substantial amount of metal from the work piece and the other adapted for the removal of a smaller amount of metal but capable aaraeeo honing tool carried by each spindle and rotatable therewith; one of said tools being adapted for the removal of a substantial amount of metal from a work piece and the, other tool being adapted for the removal of a smaller amount of metal but capable of producing a smooth finish on the work piece, meanson the work support for presenting work pieces to both tools simultaneously, means for reciprocating one of the supports to efiect relative traverse of the tools and work pieces, power actuated means for expanding the tools into operative engagement with at the end of the series'of working strokes, and other control means operative to modify the action of* said mechanism and initiate movement of the reciprocating support beyond the normal range of travel to dis'associate the tool from the work, said other control means acting a predetermined time after the operation of said first control means to insure collapse or the tool before its disassociation from the work,

21. A machine tool having; in combination, a movable work support, a tool support mounted for reciprocation toward and from the work support, means for periodically indexing said work support to present successive work pieces in operative relation to the tool carried by the tool support, means for holding the work independently of the work support while the tool is operating thereon, said holding means comprising, a;

- stationary member disposed between the work their associated work pieces, and control means for said power actuated means operable to independently vary the pressure exerted by the respective tools on their associated work pieces.

19. In a honing machine, in combination, a work support, a tool support, a honing tool carried by the tool support, actuating means for expanding the tool when operatively associated with the work and for collapsing it when disassociated from the work, means for efiecting relative rotation of the tool and work, power actuated means for reciprocating one, of said supports,

control mechanism for said power actuated means normally operative to confine the movements of the reciprocating support to a normal range of travel for efiecting relative traverse of the tool" member to clamp the work piece against said and work through a series of working strokes,

means for conditioning said-control mechanism to initiate movement of the reciprocating support beyond said normal range of travel to disassoe ciate the tool from the work, and auxiliary control, means operative to initiate the collapse of the tool while the reciprocating support is within its normal travel range;

20. ha honing ,machine, in combination, a

7 work support, a support for a honing tool, power actuated means'for expanding and collapsing the tool, means for effecting relative rotation of the.

tool and work. drive meanstorreciprocating one oi said supports, control mechanism for said drive support and the tool support, a clamping member located on the opposite side of the work support from said stationary member and movable toward the same to engage a work piece and clamp it against the stationary member, and power actuated means for moving said clamping member;

22. A machine tool having, in combinatiom'a support for a tool, power actuated means for ro-' .tating the tool and reciprocating the support, a work support, means for indexing the work support to carry a succession of work pieces into position to' be operated upon'by the tcol, means for holding the work piece independently of the work support while the tool is' operating thereon comprising, a stationary member disposed at one side of the work support, a clamping member disposed on the oppositeside oi the work support substantially in alinement with the tool and the work piece to be operated upon, and power actuated means for operating said clamping worksupport, means for indexing the work support to carry a succession of work pieces into position to be operated upon by the tool, means for holding the work piece independently oi the work support while the tool is operating thereon,

said holding means comprising, a stationary 4 member disposed at one side of the work support, hydraulic cylinder and piston means dismeans operative to confine the movements of the reciprocating support toa normal range or travel wherein the tool and work are relatively traversed through a series of working strokes, control means for said power actuated means operative while the reciprocating support is within its normal trav el range to initiate the collapse of the tool cylinder to actuate posed on the opposite side of the work support, said piston having a rod arranged substantially in alinement with the tool and work piece to be operated upon and operative in the movement 0! the piston to engage the work piece and clamp the same against said stationary member,

and means for supplying pressure fluid to sai the piston.

ALBERT m. JOHN-SON.

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