US3844069A

US3844069A - Automatic loading mechanism and grinding machine

Info

Publication number: US3844069A
Application number: US00280778A
Authority: US
Inventors: L Shank
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-08-15
Filing date: 1972-08-15
Publication date: 1974-10-29
Anticipated expiration: 1991-10-29

Abstract

A machine for grinding the opposite ends of helical springs comprising a horizontal carrier plate mounted for continuous rotation about an upright axis. Spaced upper and lower grinding wheels or discs are disposed in parallel straddling relation with respect to a peripheral portion of said carrier plate. The facing surfaces of the grinding wheels are substantially flat and parallel, and of an abrasive grinding material. A stationary floor member is disposed beneath said carrier plate, the floor member having an upper surface immediately adjacent thereto which lies on a plane substantially coincident with the upper surface of the lower grinding wheel. The floor member has an edge disposed closely adjacent to the lower grinding wheel thereby to provide a transition path for springs moved from said floor member to the space between said grinding wheels. A plurality of equally spaced holes in the peripheral portion of said carrier plate are circularly arranged coaxially with respect to the aforesaid upright axis. The facing grinding surfaces of the wheels are of a substantially congruent annular shape, said grinding surfaces straddling the carrier plate such that the inner perimeters thereof are disposed axially opposite an imaginary circle substantially through the centers of said holes whereby the springs carried by the holes in the rotating plate will follow an arcuate path that contacts the full radial extent of said grinding surfaces. A spring-feeding device is disposed above and in registry with said holes for selectively introducing springs thereinto. This device has a magazine for storing a plurality of helical springs in end-to-end relation and locking means selectively operable to release one spring at a time for introduction into a respective one of said holes.

Description

States atent Oct. 29, 1974 1 AUTOMATIC LOADING MECHANISM ANI) GRINDING MACHINE [76] Inventor: Leland R. Shank, 513 S. Wayne St.,

Angola, 1nd. 46703 22 Filed: Aug. 15,1972 [21] Appl. No.: 280,778

Primary Examiner-Al Lawrence Smith Assistant ExaminerNicholas P. Godici Attorney, Agent, or Firm-Gust & Irish 5 7] ABSTRACT A machine for grinding the opposite ends of helical springs comprising a horizontal carrier plate mounted for continuous rotation about an upright axis. Spaced upper and lower grinding wheels or discs are disposed in parallel straddling relation with respect to a peripheral portion of said carrier plate. The facing surfaces of the grinding wheels are substantially flat and parallel, and of an abrasive grinding material. A stationary floor member is disposed beneath said carrier plate, the floor member having an upper surface immediately adjacent thereto which lies on a plane substantially coincident with the upper surface of the lower grinding wheel. The floor member has an edge disposed closely adjacent to the lower grinding wheel thereby to provide a transition path for springs moved from said floor member to the space between said grinding wheels. A plurality of equally spaced holes in the peripheral portion of said carrier plate are circularly arranged coaxially with respect to the aforesaid upright axis. The facing grinding surfaces of the wheels are of a substantially congruent annular shape, said grinding surfaces straddling the carrier plate such that the inner perimeters thereof are disposed axially opposite an imaginary circle substantially through the centers of said holes whereby the springs carried by the holes in the rotating plate will follow an arcuate path that contacts the full radial extent of said grinding surfaces. A spring-feeding device is disposed above and in registry with said holes for selectively introducing springs thereinto. This device has a magazine for storing a plurality of helical'springs in end-to-end relation and locking means selectively operable to release one spring at a time for introduction into a respective one of said holes.

9 Claims, 9 Drawing Figures PATENTEDucrzs p914 smaznur 4 V II! IIIIIIIIPIIIIIII IIIIIIL II IIIIII IlIXIlIlIlIlIlIH BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to the fabrication of helical coil springs, and more particularly to a machine for grinding the end coils of conventional helical springs.

2. Description of the Prior Art It is conventional to grind the end coils of a helical spring flat in planes normal to the spring axis. Various machines have been devised for performing this operation either automatically or semi-automatically, a typical such machine utilizing a carrier plate in the form of a disc having a multiplicity of holes coaxially arranged therein adapted to receive helical springs, the thickness of the disc being slightly less than the free height of the springs. Two grinding wheels are disposed adjacent to the disc in straddling relation so as to engage the end coils of the springs projecting beyond the surfaces of the disc. Rotation of the disc thereby serves to pass the springs between the grinding surfaces for grinding flat the end coils thereof. Various means and devices have been proposed in the past for either manually or automatically inserting the springs in the carrier disc prior to the grinding operation.

SUMMARY OF THE INVENTION In accordance with the broader aspects of this invention, there is provided in a machine for grinding the opposite ends of helical springs, mechanism comprising a horizontally disposed carrier plate mounted for rotation about an upright axis. Means for continuously rotating the plate at a predetermined speed are provided, and upper and lower spaced-apart grinding wheels are disposed in parallel straddling relation with respect to a peripheral portion of the carrier plate. The facing surfaces of the wheels are substantially flat and parallel and of an abrasive grinding material. A stationary floor member disposed beneath the carrier plate has an upper surface immediately adjacent to the carrier plate which lies on a plane substantially coincident with the upper surface of the lower grinding wheel. The floor member has an edge disposed closely adjacent to the lower grinding wheel thereby to provide a transition path for springs moved from the floor member to the space between said grinding wheels. A plurality of equally spaced holes are provided in the peripheral portion of said carrier plate circularly arranged coaxially with respect to said upright axis. The facing grinding surfaces of the wheels may be of substantially congruent annular shape such that the inner perimeters thereof are disposed axially opposite an imaginary circle traced substantially through the centers of the holes whereby springs carried by the holes in the rotating plate will follow an arcuate path that contacts the full radial extent of said grinding surfaces. A spring-feeding device is disposed above and in registry with said holes for selectively introducing springs into the holes. This device has a magazine for storing a plurality of helical springs in end-to-end relation and to release one spring at a time for introduction into a respective one of said holes.

It is an object of this invention to provide in a machine for grinding the opposite ends of helical springs or similar articles mechanism for efficiently, reliably and economically feeding springs or such articles automatically into the carrier of the machine.

It is another object of this invention to provide an automatic grinding machine for grinding automatically the ends of articles such as springs in a manner such as will not require a person or persons to hand load the articles.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a top plan view of one embodiment of this invention;

FIG. 2 is a fragmentary sectional view taken substantially along section line 2-2 of FIG. 1;

FIG. 3 is a fragmentary perspective of the machine of FIG. 1;

FIG. 4 is a fragmentary sectional view taken substantially along section line 4-4 of FIG. 1;

FIGS. 5a and 5b are before and after views of a spring delivered to the machine of the preceding Figs. and ground thereby;

FIG. 6 is a fragmentary side elevation partly sectioned for clarity of illustration of the machine of the preceding Figs.;

FIG. 7 is a fragmentary top plan view, also partly sectioned for clarity of illustration, of a part of the feeding mechanism thereof;

FIG. 8 is a fragmentary perspective view of the same feeding mechanism; and

FIG. 9 is a fragmentary top plan view of another embodiment.

Referring to the drawings, the machine of this invention includes a rigid, stationary, table-like frame indicated generally by the reference numeral 10 having mounted thereon a disc-shaped carrier plate 12 for rotation about an upright axis. Mounted on frame 10 for rotating the carrier plate 12 is a drive train which includes an electric motor 14, a gear box 16, a gear reducer 18, and a shaft 20 from the gear reducer 18 which suitably connects to and supports the carrier 12. An output shaft 22 from the gear box 16 connects to an input shaft 24 on the gear reducer 18 for driving the latter. The speed reduction is such that with the electric motor 14, which is adjustable in speed, operating at an appropriate speed, the carrier plate 12 will be rotated relatively slowly as will become apparent from the description later on.

Secured to the frame 10 is a stationary, horizontal floor plate 26 which is disposed immediately beneath the carrier plate 12 in parallelism therewith. In the peripheral portion of the carrier plate 12 is provided a multiplicity of equally spaced holes 28 arranged in a circle concentric with the axis of rotation of the carrier 12. These holes 28 are substantially the same size with the upper ends thereof being slightly chamferred at 30 as more clearly shown in FIGS. 2 and 4.

Disposed in parallel straddling relationship with a peripheral portion of the carrier 12 are two grinding discs or

wheels

32 and 34, respectively. These

wheels

32 and 34 are mounted for rotation about an upright axis parallel to the shaft axis of the carrier 12 and include two

steel supporting discs

36 and 38, respectively, to which are suitably secured by bolts 44 two grinding rings 40 and 42 as shown. These grinding rings 40 and 42 are disposed coaxially with the axis of rotation of the two

wheels

32 and 34 with the facing

surfaces

46 and 48 thereof being horizontal and parallel and disposed closely adjacent a predetermined distance from the respective surfaces of the carrier 12. It may be here stated that the spacing between the two

surfaces

46 and 48 will determine the free length of the helical spring which has been ground by the machine. Preferably, this space is made adjustable in the mechanism which supports the two

grinding wheels

32 and 34 for rotation. A suitable motor 50 mounted on the table frame connects to the

wheels

32 and 34 for driving them at relatively high speed.

As is clearly shown in both FIGS. 1 and 6, the inner perimeters 52 of the grinding rings 40 and 42 (these grinding rings being composed of conventional abrasive material) are of a diameter vertically coinciding with the circle defined by the centers of the holes 28 in the carrier 12. This circle is graphically indicated by the numeral 54 in FIG. 1. As viewed in FIG. 1, with the

grinding wheels

32 and 34 rotating at high speed and with springs inserted in the holes 28 in the carrier 12, rotation of the latter will carry the springs between the

grinding surfaces

46 and 48 along a path covering the entire radial extent of the

grinding surfaces

46, 48 such that they will wear evenly. The path traversed by the springs is shown in FIG. 1 as extending in an arc across the radial extent of the grinding surfaces as shown.

Disposed immediately adjacent to the

grinding wheels

32, 34 are dust collection or

suction tubes

56 and 58 that enter stationary guards or covers (not shown) for the

wheels

32 and 34. Such covers have been shown removed for clarity of illustrating the internal mechanism and are conventional insofar as grinding machines of this character are concerned.

A suitable electrical control box 59 contains the usual switches and wiring for controlling the operation of the machine.

Springs are fed into the holes 28 of the carrier 12 automatically by mechanism now to be described. This mechanism is shown more clearly in FIGS. 1, 4, 6, 7 and 8. Securely mounted on the floor plate 26 are two support bearings 60 which rotatably mount a horizontal shaft 62. On one end of the shaft 62 is secured a cam wheel 64 having a confined cam groove 66, and on the other end is secured a sprocket 68 and an adjustable split cam assembly 70. Mounted on a bracket 72 secured to the floor plate 26 is a cam-actuated single pole, single throw microswitch 74 having a cam operated arm 76 which carries a roller 78 engageable with the periphery of the cam 70. The switch 74 serves a purpose which will be explained later on.

A drive chain 80 connects the sprocket 68 to a sprocket 82 secured to the output shaft 84 of the gearbox 16 as shown. Thus, rotation of the motor 14 (FIG. 6) results not only in rotation at slow speed of the carrier plate 12 but also the shaft 62 and the various parts secured thereto.

A supporting or guide member 86 having a boxshaped bore 88 slideably receives a pitman 90 of the same cross-sectional shape for rectilinear movement. A cam follower 92 is secured to the left end (see FIG. 7) of the pitman 90 as shown, this follower 92 cooperatively engaging the cam groove 66 in the wheel 64. On the other end of the pitman 90 is mounted a hollow nozzle support head 94 having a tubular shaped member or nozzle 96 secured therein by means of a set screw 98. Secured to the supporting head 94 by means of threaded fasteners 100 is an electrical solenoid 102 having a reciprocable plunger 104 which passes through companion bores in both the head 94 and the tubular member 96. As shown in FIG. 7, the plunger 104 is projecting into the space of the tubular member 96. The solenoid 102 is so constructed that upon deenergization thereof, the plunger 104 will be retracted from the position shown to one in which the distal end is clear of the inner space of the tubular member 96. Upon energization thereof, the plunger 104 is protracted into the tubular member 96 to an extent as will be explained more fully later on. The solenoid 102 is connected to the switch 74 for selective momentary actuation corresponding to the rotation of a split cam 70. Split cam 70 has a raised portion on its periphery that provides for the momentary actuation of the switch 74 and solenoid 102 as will become apparent from the description later on.

In the embodiment illustrated, the pitman 90 and its associated parts are situated tangentially with respect to the circle 54.

One end of a metallic tube 106 is telescopically secured to the tubular member 96 as shown and leads to a conventional vibratory feeding mechanism 108 shown more clearly in FIG. 3. This feeding mechanism 108 is adapted to feed springs contained in the bowl 110 sequentially into the entrance end 112 of the tube 106 which is of such size as to permit gravitational feeding of such springs in end-to-end relation to the tubular member 96. The feed-mechanism is so timed that the plunger 104 is momentarily reciprocated to allow one spring to fall from the tubular member or nozzle 96 but to engage and hold the next spring thereabove in position. Thus, the mechanism serves to release only one spring at a time from the nozzle 96, the remaining springs being held thereabove in the tubular member 96 and feeding tube 106 which may now be characterized as a

magazine

96, 106, inasmuch as it contains a multiplicity of springs in end-to-end relation which may be ejected or released from the nozzle 96 one at a time. The mechanism is initially adjusted such that the nozzle 96 is positioned immediately above the holes 28 in the carrier 12 such that springs may be successively fed into the holes 28 as the carrier 12 rotates continuously. This operation will be explained more fully later on.

Referring now to FIGS. 1, 2, and 3, a springcompressing member 114 is secured in stationary position to the floor member 26 so as to overlie the carrier 12, as shown in FIG. 2, immediately adjacent to the grinding wheel 34. The member 14 preferably is formed with an arcuate channel 116 (FIG. 2) conforming to the curvature of the hole circle 54 (see FIG. 1) having a width corresponding to the hole 28 diameter. This groove 116 has an upper wall 118 inclined as shown in FIG. 2 which serves to compress springs 120 in the holes 28 against floor plate 26 to a height substantially equal to the thickness of the carrier 12. At this height, the springs may be inserted into the space between the two grinding rings 40, 42, also shown in FIG. 2.

It should be noted in FIGS. 1 and 2 that the floor plate 26 has an arcuate edge 122 positioned immediately adjacent to the periphery of the grinding ring 42 with the clearance being much less than the diameter of one of the springs 120. Thus, the springs 120 may be moved by the carrier 12 from the floor member 26 to the space between grinding rings 40, 42 since the upper surface 26a of the floor plate 26 lies in a plane substantially coincident with or slightly higher than the upper surface of the grinding ring 42.

A straight bar 124 secured at one end to the floor plate 26 overlies in parallelism the carrier 12 as shown more clearly in P16. 1. Thus, any springs loose on the upper surface of the carrier 12 will engage the bar 24 and be swept off without being carried around into the grinding

wheels

32 and 34. Also to assist in preventing grinding dust from getting into the cams and related driving mechanism is a flexible curtain 126 of leather plastic or the like which is secured to a horizontal frame member on the supporting frame. This curtain 126 overlies the upper surface of the carrier 12 in rubbing engagement therewith.

In operation, springs of a common length with unground end coils as shown in FIG. 5a are loaded into the vibratory feeder 108. The feeder operates automatically sequentially to feed such springs into the end 112 of the tube 106 which drop downwardly until they engage the plunger 104 of solenoid 102, there to be held against falling from the nozzle 96. The motor 14 is energized thereby causing rotation at uniform speed of the carrier 12 as well as the shaft 62. The cam groove 66 in the wheel 64 is so formed that the pitman 90 will be reciprocated at a speed with an excursion as will cause the nozzle 96 to move on its protractile stroke (arrow P in FIG. 7) in synchronism with a respective hole 28 immediately followed by opposite retractile stroking thereof at the end of which it registers with the next succeeding hole 28 and then follows this hole in synchronism and in vertical registry therewith in protraction. This cycle repeats itself continuously with solenoid 102 being momentarily actuated for feeding springs from the

magazine

96, 106 individually into each of the holes 28 as they come into registry with the nozzle 96.

The actual feeding of the springs individually from the nozzle 96 into the individual holes 28 will now be explained. Assume that the pitman 90 is protracted toward the right as'in FIGS. 7 and 8 to the point of its maximum excursion, in which position it is in vertical registry with one of the openings 28, and then due to rotation of cam wheel 64 starts to retract. The electrical solenoid 102 is at this moment de-energized by reason of the action of the split cam 70 on the switch 74 thereby retracting plunger 102 and releasing one spring in

magazine

96, 106 permitting it to fall downwardly until it engages the upper surface of the carrier 12. Continued rotation of the shaft 62 and passage of the raised portion of split cam 70 results in almost immediate re-energization of the solenoid 102 forcing the plunger 104 against the spring 120 just above the one that has fallen onto the carrier 12 surface. The nozzle 96 continues its retractile stroke due to the cam groove 66 in the wheel 64 until the spring which is partially emerging from the nozzle 96 comes into registry with the next succeeding empty hole 28. The spring being in registry with this hole starts to fall thereinto at which time the nozzle 96 is protracted forwardly in synchronism and registry with that hole by reason of the shape of the cam groove 66. By the time the nozzle 96 completes its protractile stroke, the spring therein will have fully dropped into the respective hole and cleared the nozzle 96 for the beginning of its retractile stroke at which the solenoid 102 cycles and permits one spring in the

magazine

96, 106 to drop from the nozzle onto the carrier surface for a rearward sliding movement until it comes to the next succeeding empty hole 28. This cycle repeats itself continuously dropping one spring into each hole 28 as it passes.

The springs (FIG. 5a), with unground end coils, project slightly above the surface of the carrier 12, the bottom ends resting slideably on the floor plate 26. As the carrier 12 rotates, it brings them into engagement with compressing member 114 which squeezes the springs into the confined space between the grinding rings 40 and 42. As the carrier 12 continues its rotation, the springs follow an arcuate path between the parallel surfaces of the rings 40 and 42, this path extending from the outer to inner perimeters of the grinding

surfaces

46 and 48, thereby producing even wear thereof. By the time the springs emerge from the grinding wheels, the end coils are ground flat as shown in FIG. 5b. Thus, springs are continuously fed into the holes 28 and continuously ground, the ground springs as they emerge from the grinding wheels dropping from the holes 28 in the vicinity of the numeral which registers with a cutaway portion 127 in the floor plate. A box beneath this cutaway 127 can thereby receive the springs as they are dropped.

The holes 28 are slightly larger than the diameter of the springs to permit easy insertion thereinto. In the feeding action, if a spring'should drop from the nozzle 96 onto a spring therebeneath in a hole 28, it will merely slide off with movement of the nozzle. The unground springs are of a length slightly greater than the thickness of the carrier 12 thereby to expose end coils for grinding by the rings 40, 42 which are preferably equally spaced from the respective carrier surfaces.

The invention is useful in grinding articles other than springs such as metallic pins, studs or the like.

For some springs or in the alternative metallic pins having flat ends, the

solenoid escapement mechanism

102, 104 may be omitted. For those springs having end coils that do not catch on to one another, the next upper spring in the nozzle 96 merely rides during the protractile stroke on the lower spring which is entering or has entered a hole 28. Upon retraction of the nozzle 96, the upper spring merely slides off the end of the lower spring onto the carrier and then into the next succeeding empty hole 28.

If springs tend to catch in the

magazine

96, 106 or onto each other, the operation of the solenoid 102 jars the springs causing them to move in the magazine and also to separate from the one that is being dropped into a carrier hole 28.

The speed of the electric motor 14 is adjustable by means of a suitable conventional manual control (not shown) thereby to operate the carrier 12 and the nozzle mechanism at different speeds as may be required for most efficacious operation of the machine.

in a working embodiment of this invention, there are 120 holes 28, the spacing between centers of holes 28 is 0.604 inches, the radius of carrier 12 measured from circle 54 is ll.50 inches, the diameter of the holes is 0.245 inches and the thickness of the carrier 12 is 0.700 inches. A typical length of unground springs 120 is 0.835 inches, the diameter 0.230 inches, and the length of the ground spring 0.775 inches.

A further embodiment is shown in FIG. 9 wherein a plurality of additional coaxial rings 54a and 54b of holes 28a and 28b respectively, are fed by respective nozzles 96a and 96b. A bar 150 is rotatably journalled on the shaft to swing horizontally in parallelism with and a fixed distance above the carrier 12. The

nozzles

96, 96a and 96b are mounted thereon in radially spaced relation with respective tubes, like tube 106, being connected thereto as previously described. The pitman 90 is pivotably connected to the outer end of the bar 150 by a pivot link 152. Thus as the pitman reciprocates, the bar 150 will be correspondingly swung about the shaft 20 and axis of the carrier 12. The holes 28, 28a and 28b in the respective hole rings are equally spaced apart in registry with the

nozzles

96, 96a and 96b, respectively. The spacing between holes is such that the excursion of the nozzles will drop one spring in each succeeding hole as previously explained. In the preferred embodiment, each nozzle is equipped with a solenoid which operates from the split cam 70 such that all nozzles discharge springs simultaneously into the respective holes.

By reason of the pivoting action of the bar 150, the nozzles are swung on arcs coinciding with the hole rings, respectively, with which they are associated thereby assuring proper registry of the nozzles with the holes during the feeding operation. This is to be contrasted with rectilinear tangential movement of a nozzle which tends to move the nozzle out of registry with the hole sometime during its excursion. However, for the embodiment of FIGS. 1-8, the parameters of the various parts, such as the diameter of the hole ring 54, hole spacing, etc., provide for reliable, sequential feeding since the tangential motion of the nozzle 96 remains in substantial registry with the hole through its excursion.

While there have been described above the principles of this invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention.

What is claimed is:

1. In a machine for grinding the opposite ends of helical springs, mechanism comprising a horizontally disposed carrier plate mounted for rotation about an upright axis, means for continuously rotating said plate at a predetermined speed, upper and lower spaced apart grinding wheels disposed in parallel straddling relation with respect to a peripheral portion of said carrier plate, the facing surfaces of said wheels being substantially flat and parallel and of an abrasive grinding material, the axis of each grinding wheel being radially spaced from said carrier plate axis, a stationary floor member disposed beneath said carrier plate, said floor member having an upper surface immediately adjacent to said carrier plate lying in a plane substantially coincident with the upper surface of said lower grinding wheel, said floor member having an edge disposed closely adjacent to said lower grinding wheel thereby to provide a transition path from springs moved from said floor member to the space between said grinding wheels, a plurality of holes in the peripheral portion of said carrier plate circularly arranged coaxially with respect to said up right axis, the facing grinding surfaces of said wheels being of annular shape, said grinding surfaces straddling said carrier plate with the inner perimeters thereof so positioned as to have the full radial extent of said surfaces traversed by said holes in said carrier plate as the latter is rotated whereby springs carried by said holes in said rotating plate will follow a path that contacts the full radial extent of said grinding surfaces, a spring-feeding device disposed above and in registry with said holes for selectively introducing springs into said holes, said device having a magazine for storing a plurality of helical springs in end-to-end relation, a nozzle connected to said magazine, means mounting said nozzle and magazine for movement a predetermined distance above and in parallelism with said carrier plate in cooperative relation with said holes, and rotary cam means responsive to rotation of said carrier plate for reciprocating said nozzle and magazine in spring-feeding synchronism with said holes.

2. The mechanism of claim 1 in which said mounting means includes a pitman guided in a stationary member for rectilinear reciprocation tangentially with respect to said circle of holes, said rotary cam means including a rotatable cam having a connection with said pitman for reciprocating the same and a drive train which is connected between said carrier plate and said rotatable cam for synchronizing the movement of said pitman with the rotation of said carrier plate.

3. In a machine for grinding the opposite ends of helical springs, mechanism comprising a horizontally disposed carrier plate mounted for rotation about an upright axis, means for continuously rotating said plate at a predetermined speed, upper and lower spaced apart grinding wheels disposed in parallel straddling relation with respect to a peripheral portion of said carrier plate, the facing surfaces of said wheels being substantially flat and parallel and of an abrasive grinding material, a stationary floor member disposed beneath said carrier plate, said floor member having an upper surface immediately adjacent to said carrier plate lying in a plane substantially coincident with the upper surface of said lower grinding wheel, said floor member having an edge disposed closely adjacent to said lower grinding wheel thereby to provide a transition path for springs moved from said floor member to the space between said grinding wheels, a plurality of equally spaced holes in the peripheral portion of said carrier plate circularly arranged coaxially with respect to said upright axis, a spring-feeding device disposed above and in registry with said holes for selectively introducing springs into said holes, said device having a magazine for storing a plurality of helical springs in end-toend relation and locking means selectively operable to release one spring at a time for introduction into a particular one of said holes, said device including a nozzle connected to said magazine of tubular form as an extension thereof, a pitman guided in a stationary member for rectilinear reciprocation tangentially with respect to said circle of holes, said nozzle and magazine being mounted on said pitman above said holes, said locking means includes the plunger of a solenoid fixedly mounted with respect to said nozzle, said nozzle having an opening in the wall thereof receiving said plunger for engagement with a spring therein, camoperated switch means responsive to rotation of said carrier plate for operating said solenoid once for each reciprocation of said nozzle, a cam wheel and follower operatively connected to said pitman, said camoperated switch includes a follower engageable with a split cam mounted on a common shaft with said cam wheel, a power operated drive apparatus connected to said carrier plate for rotating the same continuously, and a synchronous drive train coupled between said apparatus and said common shaft for causing reciprocation of said pitman as said carrier plate rotates.

4. The mechanism of claim 3 in which said split cam includes a raised portion so positioned to operate momentarily said switch and de-energize said solenoid near the end of the protractile stroke of said nozzle thereby releasing a spring from said nozzle which drops onto said carrier plate and slides therealong during the retractile stroke thereof, said switch after such momentary operation energizing said solenoid to thereby prevent release of springs from said magazine.

5. The mechanism of claim 3 in which said carrier plate has a second ring of equally spaced holes inside and concentric with said first-mentioned ring of holes, a supporting member rotatably journalled about the same axis as said carrier plate for horizontal swinging movement above said carrier plate, first and second of said magazines being mounted in radially spaced relation on said supporting member, each magazine having a solenoid and plunger associated therewith as aforesaid, said camoperated switch means being responsive to rotation of said carrier plate for operating each solenoid once for each reciprocation of said magazines, said reciprocatory mounting means being connected to said supporting member for reciprocating it in synchronism with said carrier, said first and second magazines and the nozzles thereof being disposed in vertical registry with said first and second ring of holes, respectively.

6. The mechanism of claim 5 in which said springfeeding device includes a pitman guided in a stationary member for rectilinear reciprocation in a direction tangentially with respect to said rings of holes, a link pivotably connecting said pitman to said supporting member, and cam means responsive to rotation of said carrier plate for reciprocating said pitman such that said magazines and the nozzles thereof move in synchronism and in registry with respective ones of said holes during the protractile part of the pitman movement.

7. In a machine for grinding the opposite ends of helical springs, mechanism comprising a horizontally disposed carrier plate mounted for rotation about an upright axis, means for continuously rotating said plate at a predetermined speed, upper and lower spaced apart grinding wheels disposed in parallel straddling relation with respect to a peripheral portion of said carrier plate, the facing surfaces of said wheels being substantially flat and parallel and of an abrasive grinding material, a stationary floor member disposed beneath said carrier plate, said floor member having an upper surface immediately adjacent to said carrier plate lying in a plane substantially coincident with the upper surface of said lower grinding wheel, said floor member having an edge disposed closely adjacent to said lower grinding wheel thereby to provide a transition path for springs moved from said floor member to the space between said grinding wheels, a plurality' of equally spaced holes in the peripheral portion of said carrier plate circularly arranged coaxially with respect to said upright axis, a spring-feeding device disposed above and in registry with said holes for selectively introducing springs into said holes, said device having a magazine for storing a plurality of helical springs in end-toend relation and locking means selectively operable to release one spring at a time for introduction into a particular one of said holes, said device including a nozzle connected to said magazine, means mounting said nozzle for reciprocatory movement with the protractile part of said movement being in synchronism with movement of said carrier, said locking means including an element operatively mounted on said magazine for engaging and holding springs therein, said nozzle being connected to and forming a part of said magazine such that a spring released from said magazine passes through said nozzle and into a respective hole, means momentarily actuating said locking means near the end of each protractile stroke to disengage said element from a spring permitting it to drop and to reengage the next successive spring in said magazine to hold it in place, said spring thereby dropping onto said carrier plate and sliding therealong during the retractile stroke of said nozzle until it drops into the next succeeding hole.

8. The mechanism of claim 7 in which said nozzlemounting means holds said nozzle vertically spaced from said carrier plate throughout the reciprocation thereof.

9. The mechanism of claim 1 in which the facing surfaces of said grinding wheels are substantially congruent and disposed axially opposite the peripheral portion of said carrier plate with the inner perimeters of said grinding surfaces being axially opposite an imaginary circle through the centers of said holes.

Claims

3. In a machine for grinding the opposite ends of helical springs, mechanism comprising a horizontally disposed carrier plate mounted for rotation about an upright axis, means for continuously rotating said plate at a predetermined speed, upper and lower spaced apart grinding wheeLs disposed in parallel straddling relation with respect to a peripheral portion of said carrier plate, the facing surfaces of said wheels being substantially flat and parallel and of an abrasive grinding material, a stationary floor member disposed beneath said carrier plate, said floor member having an upper surface immediately adjacent to said carrier plate lying in a plane substantially coincident with the upper surface of said lower grinding wheel, said floor member having an edge disposed closely adjacent to said lower grinding wheel thereby to provide a transition path for springs moved from said floor member to the space between said grinding wheels, a plurality of equally spaced holes in the peripheral portion of said carrier plate circularly arranged coaxially with respect to said upright axis, a spring-feeding device disposed above and in registry with said holes for selectively introducing springs into said holes, said device having a magazine for storing a plurality of helical springs in end-to-end relation and locking means selectively operable to release one spring at a time for introduction into a particular one of said holes, said device including a nozzle connected to said magazine of tubular form as an extension thereof, a pitman guided in a stationary member for rectilinear reciprocation tangentially with respect to said circle of holes, said nozzle and magazine being mounted on said pitman above said holes, said locking means includes the plunger of a solenoid fixedly mounted with respect to said nozzle, said nozzle having an opening in the wall thereof receiving said plunger for engagement with a spring therein, cam-operated switch means responsive to rotation of said carrier plate for operating said solenoid once for each reciprocation of said nozzle, a cam wheel and follower operatively connected to said pitman, said cam-operated switch includes a follower engageable with a split cam mounted on a common shaft with said cam wheel, a power operated drive apparatus connected to said carrier plate for rotating the same continuously, and a synchronous drive train coupled between said apparatus and said common shaft for causing reciprocation of said pitman as said carrier plate rotates.

6. The mechanism of claim 5 in which said spring-feeding device includes a pitman guided in a stationary member for rectilinear reciprocation in a direction tangentially with respect to said rings of holes, a link pivotably connecting said pitman to said supporting member, and cam means responsive to rotation of said carrier plate for reciprocating said pitman such that said magazines and the nozzles tHereof move in synchronism and in registry with respective ones of said holes during the protractile part of the pitman movement.

7. In a machine for grinding the opposite ends of helical springs, mechanism comprising a horizontally disposed carrier plate mounted for rotation about an upright axis, means for continuously rotating said plate at a predetermined speed, upper and lower spaced apart grinding wheels disposed in parallel straddling relation with respect to a peripheral portion of said carrier plate, the facing surfaces of said wheels being substantially flat and parallel and of an abrasive grinding material, a stationary floor member disposed beneath said carrier plate, said floor member having an upper surface immediately adjacent to said carrier plate lying in a plane substantially coincident with the upper surface of said lower grinding wheel, said floor member having an edge disposed closely adjacent to said lower grinding wheel thereby to provide a transition path for springs moved from said floor member to the space between said grinding wheels, a plurality of equally spaced holes in the peripheral portion of said carrier plate circularly arranged coaxially with respect to said upright axis, a spring-feeding device disposed above and in registry with said holes for selectively introducing springs into said holes, said device having a magazine for storing a plurality of helical springs in end-to-end relation and locking means selectively operable to release one spring at a time for introduction into a particular one of said holes, said device including a nozzle connected to said magazine, means mounting said nozzle for reciprocatory movement with the protractile part of said movement being in synchronism with movement of said carrier, said locking means including an element operatively mounted on said magazine for engaging and holding springs therein, said nozzle being connected to and forming a part of said magazine such that a spring released from said magazine passes through said nozzle and into a respective hole, means momentarily actuating said locking means near the end of each protractile stroke to disengage said element from a spring permitting it to drop and to reengage the next successive spring in said magazine to hold it in place, said spring thereby dropping onto said carrier plate and sliding therealong during the retractile stroke of said nozzle until it drops into the next succeeding hole.

8. The mechanism of claim 7 in which said nozzle-mounting means holds said nozzle vertically spaced from said carrier plate throughout the reciprocation thereof.