US2263878A - Honing machine - Google Patents

Description

3 Sheets-Sheet l NV E N TO CTTO @ley/s Nov. 25, 1941. A. M. JOHNSON HONING MACHINE Filed Jan, e, 1939 No'v. 25, 1941. A M, JOHNSON 2,263,878

- HONING MACHINE Filed Jan. 6, 1939 3 Sheets-Sheet 2 l@ L-/PS L 66 Tro'mw Nov. 25, 1941. A. M. JOHNSON HONING MACHINE 3 Sheets-Sheet 3 Filed Jan. 6, 1939 NVENTOQ/ (E4/6er C??? C70/7x? on 3J LL mi OdTTOwy/ S Patented Nov. 25, 1941 noNrNG Mao Albert M. Johnson, Beckford, n1., assigner to Barnes Drill Co., Rockford, Ill., a corporation oi' Illinois Application January 6, 1939, Serial No. 249,576

7 Claims.

reciprocation relative to the other. The tool and work are initially brought into operative .association by an advancing movement oi the reciprocatory support and thereafter that support is reciprocated through a plurality of working strokes in which the relative movements of the tool and work are conned within a predetermined range oi' travel such as to traverse the tool from one end of the work to the other. The abrasive elements of the tool are expanded into contact with the surface of the work during such reciprocation and the tool may be rotated either continuously or intermittently. When the work is iinished to the desired dimensions, the tool is contracted and the reciprocatory support is moved through a substantially longer return stroke, that is, beyond its normal range of travel to disassociate the tool and work.

One object of the present invention is to provide novel means for controlling the advancing and return movements of the reciprocatory. support in machines of the above general character so as to avoid any possibility of injury to the tool or work while the sainev are being operatively associated or disassociated.

Another object is to provide improved means for automatically slowing down the movements of the reciprocatory support as the tool and work are being moved into or out of operative relationship.

A further object is to provide novel control means for a honing machine operative when the machine is initially started to advance the reciprocatory support at a relatively slow rate until the tool and work are brought into operative engagement, to reciprocate the support at a substantiallyv higher rate of speed for a predetermined time to traverse the tool over the work, and iinally to return the support to retracted position at a relatively slow speed so as to disassociate the tool and work. A

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment illustrated in the accompanying drawings, in which:

Fig. 1 is a side elevational View of a honing machine embodying the features of the invention.

Fig. 2 is a horizontal sectional View taken along the line 2-2 of Fig. 1 showing details of the operi ating and control mechanism oi the` machine.

mechanism.

Fig. 4 is a diagrammatic view showing the hydraulic and electrical circuits of the machine and their relationship to the operating elements of the same.

While thevinvention has been illustrated and will be -described hereinafter as embodied ir a vertical honing machine of the type in which the tool ls rotated and reciprocated relative to a stationarily supported work piece, it is to be understood that it may be incorporated in other types of honing or lapping machines. It is also to be understood that various changes and modifications may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention as expressed in the appended claims.

Referring to the drawings, and more particularly to Fig. 1, the machine selected to illustrate the invention comprises generally an upright frame or column 5 having mounted on its face an adjustable table or work support 6 for supporting Work W, such as a cylinder or the like, to be operated on by the machine. The column 5 carries on its upper end a head 8 having a portion projecting beyond the face of the column to overhang the work support. A vertically disposed tubular member 9 enclosed in the projecting portion of the head 8 constitutes an operating cylinder for a reciprocatory piston I0.

Rigid with the pistonlll is a piston rod II arranged to project through opposite ends of the cylinder 9, the ends of the cylinder being closed' by conventional packing glands I2. The piston rod I I, in the present instance, constitutes a tool support or spindle andis iitted at its lower end with a socket IBB for an abrasive tool or hone H herein shown as comprising a cylindrical carrier I5 supporting a series of elongated abrasive,

stones I6 for radial movement. Any suitable and well known means may be utilized for shifting the abrasive stones to expand or ,contract the tool.

The upper end of the spindle or rod II is shaft I 9 and bevel gear 20. The motor and cross shaft are drivingly connected by a V-belt 2| running over pulleys 22 and 23 keyed to the motor shaft and cross shaft, respectively. f With the above construction, the spindle I constitutes a reciprocable support for the honing tool H, reciprocation of which is eiective to produce the relative axial movement of the tool and work required to perform a honing or lapping operation. v Such movement is imparted to the support and tool by the introduction of pressure fluid into opposite ends of the cylinder 9 alternately under control of a reversing valve RV. Pressure iluid for reciprocating the support is supplied by a pump P herein shown as being of `the constant delivery type. In order to provide for regulation of the flow of pressure fluid in the cylinder 9 and thus control the rate of movement of the tool support, a speed control valve SV is interposed between the pump and the reversing valve. Valve SV, as herein shown, is a three-port rotary valve but it will be apparent that any suitable valve may be utilized, or alternatively, a variable delivery pump may be employed to provide the desired regulation of the. flow of pressure iluid. l

Referring more particularly to Figs. 1 and 4, the pump P is herein shown as mounted in the head 8 and arranged to be driven by the spindle rotating motor M. The head in this instance is constructed to form a reservoir or sump 3| for the oil or other fluid required for the pressure system. Fluid is drawn from the sump through an intake pipe 32 and discharged by the pump under pressure through a pipe 33 which leads to one port of the control valve SV. The second port of the control valve is connected by a pipe 34 with one port of the reversing valve RV while the third port of the control valve opens into a drain 35 leading back to the sump. The reversing valve RV, which may be of any suitable and well known construction, is eiective in one position to connect the pressure pipe 34 with al pipe 36 leading to the upper end of the cylinder 9, thereby causingthe piston I0 to be moved toward the lower end of the cylinder 9. At the same time, a pipe 31 leading from the lower end of the cylinder is connected with a drain 36 whereby spent pressure iiuid from the cylinder is returned to the sump. When the valve RV is operated to its alternate position, the above connections are reversed and the piston is shifted to the upper end of the cylinder.

It will be evident that the volume of fluid delivered via the pipe 34 to the cylinder 9 may be varied within wide limits by changing the position of the movable member of the valve SV. Thus, the rate of movement of the piston I0 and that of the tool H may be varied as required. Actuation of the valve SV for this purpose may be effected at any desired time or in any suitable manner. The present invention, however, contemplates automatic operation of the valve at definite, predetermined points of the operating cycle of the machine, as will appear presently.

The operating cycle above referred to ordinarily consists of an advancing movement of the reciprocating support from retracted position to bring the tool and work into operative association, the support being thereafter reciprocated through a plurality of working strokes by which the tool is traversed repeatedly from one end of the work piece to the other. Upon completion of the required number of such working strokes, which may be determined either by counting essere the strokes or by timing this portion of the operating cycle, the support is moved beyond its normal range of travel, that is, through a substantially longer withdrawal stroke to disassociate the tool and the work. The operating cycle is then terminated by stopping the-machine. The present invention is concerned primarily with the problem of controlling the advancing and withdrawal movements of the reciprocatory support and particularly with the regulation of the rate of movement so as to effectually avoid injury to the tool and work as they are being operatively associated or disassociated.

While the sequence of operations constituting the operating cycle of the machine may be initiated and controlled in any suitable manner, it is preferred to provide a control mechanism which is largely automatic in operation so that the machine can function properly with a minimum of attention from the attendant. Referring to Fig. 4, the control mechanism of the exemplary machine includes a control member herein shown as an elongated control rod 4| disposed generally parallel to the axis of the tool supporting rod Il and supported in the head 9 for a limited endwise movement. The lower end of the control rod is provided with rack teeth which mesh with a pinion 42 fast on a cross shaft 43 having an arm 44 connected by a link 45 with an arm 46' rigid with the movable member of the reversing valve RV. Thus, the movements of the control rod are effective to operate the reversing valve between its two positions for directing pressure fluid to the upper and lower ends of the cylinder 9 alternately.

The necessary controlling movements are imparted to the control rod 4i by an actuator in the form of a collar 46 mounted on the upper end of the piston rod Il for reciprocation therewith but rotatable relative thereto. The actuator is adapted tocooperate with a series of stops on the control rod 4| including an upper limit stop 41, a lower limit stop 48 and an interme` diate stop 49. These stops are secured to the rod in a manner such that they may be readily adjusted longitudinally thereof to determine the limits of movement of the tool. In the particular form shown, the limit stops 41 and 48 define the extreme limits of movement of the tool while vthe intermediate stop 49 defines the upper limit of the working stroke.

To enable the actuator 46 to pass the intermediate stop 49 without shifting the control rod when the tool isbeing entered in or withdrawn from the work, the periphery of the actuator is formed with a cam groove 50 widened at its lower end to receive the stop 49 when the actuator is either in its normal or operated position. The upper end of the cam groove 50 is substantially narrower than the lower end and is located so as to receive the intermediate stop only when the actuator is rocked to operated position.

Movement of the actuator 46 from normal position to operated position is eiected in certain instances by the camming action of the stop 49 in the cam groove 50 and in other instances by an operating member in the form of an elongated gear segment 5I meshing with teeth cut in the periphery of the actuator. The length of the gear segment is such that the parts are engaged at all times while the actuator reciprocates with the piston rod Il.

As herein shown, the gear member 5I is mounted on a vertical rock shaft 52 arrangedto be rocked about its axis either manually as by a handle or manual operator 52* or by a solenoid PS commonly .known in the art as the pullout solenoid. To this end, the rock shaft 52 is provided with a crank 53 which is connected by a rigid link 54 with a crank arm 55 fast on a horizontal shaft 56 journaled in suitable bearings at the rear of the head 8, as shown in Figs. l and 2. The shaft 56 is operatively connected with the armature 51 of the solenoid by a link 58 pinned to a crank arm 59 fast on the shaft. A torsion spring l interposed between the rock shaft 52 and the segment gear 5l normally acts to hold the rock shaft and associated elements of the linkage as well as the actuator 46 in their normal positions as shown in the drawings.

According to the present invention, the rocking movements of the shaft 56, whether imparted by the solenoid PS, the manual operator 52a or by the cam action of the stop 49, are utilized to operate the speed control valve SV so as to slow down the movement of the tool as it is entering or leaving the work. For this purpose, there is pinned or otherwise suitably secured to the shaft a sleeve member 60 having a radially projecting arm 6| apertured at its free end for the reception of a threaded rod 63 which is pivotally connected at one end to a crank arm 64 rigid with the movable member of the valve SV.

Collars 65 and 66 threaded on the rod on opposite sides of the arm 6I, as shown in Fig. 3, constitute abutments engageable by the arm incident to the rocking of the shaft 56. Thus, when the shaft is rocked to its normal position shown in Fig. 4, the arm 6| engages the stop 66 and shifts the valve SV to full open position. When the shaft 56 is rocked to its alternate position, as shown in Fig. 3, the arm 6| engages the stop 65 and shifts the valve to partially open position. The degree of movement imparted to the valve member may be varied as required, by simply turning the collars 65 and 66 relative to the rod and thus moving them toward or from the arm 6l. In this way, the variations in the speed of the reciprocating support effected by the valve SV may be regulated with a high degree of accuracy.

The manner in which the operation of the speed control valve is coordinated with the other operations of the machine may be best explained by describing a complete cycle of operation. With this in View, it may be assumed that the work piece W has been securely clamped to the work table 6 and that the tool is in withdrawn position with the piston I0 in the upper end of the cylinder 9, as shown in Fig. l. In moving into this position in the preceding operating cycle, the actuator 46 engaged the upper limit stop 41 and shifted the reversing valve RV to the position shown in Fig. 4 so that pressure iiuid will be supplied to the upper end of the cylinder 9 when the pump P is started. The pump does not operate, however, nor does the tool rotate until the machine cycle is initiated by a manual operation.

To initiate an operating cycle, the attendant manually closes a start switch S-I (Fig. 4) which connects a relay R-l across line conductors L--l and L-2 of a power line which includes a third line conductor L-3. Relay R-l becomes energized and closes switch R-I I, thereby connecting the motor M to the power line. The motor drives the pump P which supplies pressure uid to the upper end of the cylinder 9, thus forcing the piston I0 toward the lower end of the cylinder and'advancing the tool H toward the work piece.

A momentary operation of the switch S-l is suicient to start the cycle as the relay R-I completes a holding circuit' for itself by way of switch R-I2'and a limit switch LS which is closed incident to the initial movement of the tool. Closure of the switch LS is effected in the present instance by a stop rod 1l Which carries:

a cam 12 engageable with the operating arm of the switch. The stop rod also-has an armv 13 which is engaged by the actuator 46 as it .approaches its uppermost position. In this way, 1

the limit switch is opened and the operating cycle of the machine is interrupted automatically when the tool is retracted to its upper limit position.

As the tool H approaches the work in its downward movement, the intermediate stop 49 enters the cam slot 50 in the actuator and rocks the same to passing position. The rotation of the actuator is transmitted to the shaftA 56 through the linkage hereinbeforc described, and through the action of the arm 6I the movable valve member of the valveSV is rocked in a clockwise direction to by-pass a portion of the pressure iluid through the drain 35, thus cutting down the volume of fluid delivered to the cylinder 9. Accordingly, therate ofmovement of the piston l0 and likewise the movement of the tool support and tool H is slowed down automatically so that the tool can enter the work piece without danger of damaging the tool or the work.

As soon as the tool is properly entered in the work, the actuator 46 passes the intermediate stop 49 which, of course, has been properly set to define theupper'limit of the working stroke required by the particular work piece being operated on. 'I'he actuator and associated elements are thereupon restored to normal position. As this occurs, the shaft 56 acting through the arm 6l sets the valve SV so as to direct a greater volume of pressure fluid to the cylinder 9. The piston l0 accordingly continues its downward movement but at a substantially higher speed until the actuator engages the lower limit stop 48 and shifts the reversing valve RV to its alternate position. The pressure fluid connections to the cylinder 9 are thus reversed and the piston is forced upwardly. Since the actuator 46 has been restored to normal position, it will now engage the intermediate stop as the tool approaches the upper end of the work piece so that the next reversal of the tool stroke will occur while the tool is still in the work piece.

Through the action of the control elements above described, the tool His reciprocated relatively rapidly between the working stroke limits defined by the lower limit stop 48 and the intermediate stop 49, thereby traversing the tool repeatedly from one end of the work piece to the other. The working reciprocations of the tool may be interrupted when the work piece is nished to the desired dimension by rotating the actuator 46 to passing position in which the upper end of the cam groove 50 is alined with the intermediate stop 49 so that the actuator may pass that stop without operating the reversing valve. This may be done either-'manually by means of the operator 52a or automatically under control of an auxiliary control device such as a stroke counter or timer arranged to energize the solenoid PS at the proper time,

The auxiliary control device, as herein shown, is in the form of an electrically operated timer T of suitable and well known construction. The

timer is preferably connected in multiple with themotor switch relay R-I so as to start it in operationsimultaneously with the starting of the motor M at the beginning of the operating cycle. At the end ofthe predetermined time interval for which the timer is set, a switch TS is closed to complete a circuit for a relay R-2 which in turn closes a circuit by way of switch R-2l to energize the pull-out solenoid PS. Manually operable switches S-S and S-4 are included in the circuit of the relay R-Z so that the working reciprocations may be increased or decreased independently of the timer if necessary.

The pull-out solenoid PS, when energized in I response to the closure of the timer switch TS or the manual switch S--4, rocks the shaft 56 into the position shown in Fig. 3, thereby shifting the actuator 46 to passing position and at the same time setting the speed control valve SV in position to reduce the volume of pressure fluid supplied to the cylinder il and thus slow down the movement of the tool. Accordingly, the piston lo in its next upward stroke moves to the upper end of the cylinder 9, the actuator passing intermediate stop 49 without operating the reversing valve. This upward stroke is executed at reduced speed due to the setting of the valve SV so that the tool may be withdrawn from the work without any possibility of injury either to the tool or work.

The machine is stopped automatically when the tool is fully retracted by the opening of the limit switch LS incident to the actuator engaging the cam 13 of the stop rod 1I, as hereinbefore explained. The actuator likewise engages the upper limit stop 41 and reverses the position of the valve RV, thereby conditioning the machine for the next operating cycle.

It will be apparent from the foregoing that the invention provides improved control means for honing machines whereby the relative movements of the tool and work to operatively associate or disassociate the'same may be regulated automatically so as to eiectually avoid injury to the tool and work. 'I'he improved control means is particularly adapted for slowing down the relative approaching and withdrawal movements of the tool and work Without interfering with the reciprocation of the same in the working stroke at the normal speed required for efilcient operation of the machine.

I claim as my invention:

1. In a honing machine having a tool support and a work support arranged for relative rotation and simultaneous relative reciprocation. pressure fluid actuated means for producing such relative reciprocation, control mechanism for said pressure fluid actuated means including means 'initially operative to associate the tool and work and then to effect a plurality of working reciprocations between the tool and work, a valve aociated with said control mechanism operable to regulate the rate of relative movement of the tool and work, an auxiliary control device operative to set said control mechanism so as to immediately terminate said working reciprocations and to disassociate the tool and the work, and means actuated in response to the operation of said auxiliary device simultaneously with the setting of said control mechanism for operating said valve to slow-down the relative gaging member on said support operable in one l position to engage one of said limit stops and said intermediate stop and in the other position to engage said limit stops only incident to the reciprocation of the support and thereby shift the control rod so as to reverse the direction of movement of the support, and means operated incident to the movement of said stop engaging member from one position to the other position `for changing the rate of movement of the sup- Dort.

3Control mechanism fora honing machine having a reciprocatory support comprising, in combination, an actuating member reciprocable with the supporta control rod mounted adjacent the reciprocatory path of the support, a pair. of limit stops mounted on said'rod in spaced relation, said stops being positioned on opposite sides of said actuating member and alternately engageable thereby to define the extreme limits of movement of the support, an intermediate stop mounted on said rod between said limit stops and engageable by said Iactuating member to define with one of said limit stops the working stroke of the spindle, means for effecting a relative movement between said actuating member and said control rod to enable the member to pass said intermediate stop without engaging the same whereby to permit movement of the support beyond the range of its working stroke, and means operated incident to the relative movement of the actuating member and control rod for changing the rate of movement of the support.

4. Control mechanism for a honing machine having a reciprocatory'support comprising, in combination, an actuating member reciprocable with the support, a control rod disposed adjacent the reciprocatory path of the support, a pair of limit stops mounted on said rod in spaced relation, said stops being positioned on opposite sides of said actuating member and alternately engageable thereby to define the extreme limits of movement of lthe support, an intermediate stop mounted on said rod between said limit stops and engageable by said actuating member todefine with one of said limit stops the'working stroke of the spindle, a solenoid operable to effect a relative movement between said actuating member Vand said control rod to enable the memberto pass said intermediate stop and thereby permit the support to move beyond the range of its working stroke, and means operated by said solenoid for controlling the rate of movement of the support.

5. Ahoning machine having, in combination, a reciprocatory support, pressure fluid operated means for reciprocating said support, a valve for said pressure fluid operated means operable to control the direction of movement of the support, a second valve for said pressure fluid operated means operative to control the rate of movement of the support, a control rod extending generally parallel to the reciprocatory path of the support, said rod being shiftable to operate said first valve, a pair of limit stops mounted on said rod 'in spaced relation, an intermediate stop mounted on said rod between said limit stops, a stop engaging member on the support operable in one position to engage one of said limit stops and said intermediate stop and in the other position to engage only said limit stops incident to the reciprocation of the support whereby to shift the control rod to operate said iirst valve, and means operated coincidental with the movement of said stop engaging member from one position to the other to operate said second valve.

6. A honing machine having, in combination, a reciprocatory support, power actuated means i'or reciprocating said support, a control device for said power actuated means operable to control the able in another position to engage only said limit stops incident to the reciprocation of the support whereby to shift the control rod for operating said iirst control device', and power actuated means for moving said stop engaging member from one position to the other and for simultaneously operating said second control device.

7. In a honing machine having -a tool support and a work support arranged for relative rotation and simultaneous relative reciprocation, the combination of power actuated means for producing such relative reciprocation, control mechanism for said power actuated means including means initially operative to associate the tool and work, then to effect a. plurality of working reciprocations therebetween and ilnally to disassociate the tool and work, an auxiliary control device operable to condition said control mechanism forl disassociating the tool and the work, and means actuated by said device simultaneously with the conditioning of the control mechanism for slowing down the relative movements of the tool and work immediately prior to their disassociation. ALBERT M. JOHNSON.

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