US3699908A

US3699908A - Fluid sensing cutter control

Info

Publication number: US3699908A
Application number: US130137A
Authority: US
Inventors: Joseph M Hoffee
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-01
Filing date: 1971-04-01
Publication date: 1972-10-24
Anticipated expiration: 1989-10-24

Abstract

A pneumatic control device suitable for activating a shear and for attachment to a sewing machine employs two sensing air jets in a shoe and block combination, the shoe and block being spaced apart for the reception of work material. The distances between the sensing jets and the shear are separately adjustable, either continuously or step-wise. A shuttle valve and pulse generators are so arranged that interruption of the first jet by work material causes a first cutting stroke of the shear and essentially immediate retraction of the shear to a rest position, and so that restoration of the second sensing jet resulting from removal of the work material causes a similar second cutting stroke.

Description

United States Patent Hoffee FLUID SENSING CUTTER CONTROL Joseph M. Hoffee, 725 Sixth Avenue, New York, NY. 10009 Filed: April 1, 1971 Appl. No.: 130,137

Inventor:

References Cited UNITED STATES PATENTS 4/1968 Pitney ..73/37 2/1969 Miller et al. ..112/130 7/1971 Martinez ..l37/81.5 1/1972 Conner ..l 12/DIG. 2

DETECmR RECE/VER REgg/VER 1 Oct. 24, 1972 5 7 ABSTRACT A pneumatic control device suitable for activating a shear and for attachment to a sewing machine employs two sensing air jets in a shoe and block combination, the shoe and block being spaced apart for the reception of work material. The distances between the sensing jets and the shear are separately adjustable, either continuously or step-wise. A shuttle valve and pulse generators are so arranged that interruption of the first jet by work material causes a first cutting stroke of the shear and essentially immediate retraction of the shear to a rest position, and so that restoration of the second sensing jet resulting from removal of the work material causes a similar second cutting stroke.

10 Claims, 9 Drawing Figures WORK PIECE A KEGUMTUI? ENSDR E} Jsruz SENSOR JET! REGULATOR v 40 AMPL lF/ER VAL YES BELLOWS ACTUATED PULSE G'E/i/[RflN/PS Sill/7726' VALVE P/LOI' VALVE 59 AIR CYLINDER 72) 467-04 TE sc/ssafis PATENTED CT 24 1972 sum 1 [IF 6 INVESTOR. JOSEPH M. HOFFEE PATENTED i973 3.699.908

sum 2 OF 6 30 V P-4 m IXVENTOR. JOSEPH M. HOFFEE PATENTEDncr 24 I972 SHEET 3 OF 6 INVENTOR. JOSEPH M. HOFFEE SHEEI 5 0F 6 PATENTED 0m 24- I972 INVENTOR. JOSEPH M. HOFFEE ATTORNEYS PATENTED H 24 3 699.908

SHEEI s or 6 DETEC7DR RECEIVER RECEIVER JET 1 #2 WORK PIECE A 1 P66001701? SEA/50R AIR 0 I JET#2 40 SENSOR JET 1 REGULATOR l i r 0 I l l 47 40 AMPLIFIER VAL VES l BEAAOWS 4670A TED.

l A. I 4/ L L J PULSE G'E/VfRflTO/PS Sm/7745 v44 1 5 1 /407 VALVE 39 AIR c Y1. INDER INVENTOR. JOSEPH M. HOFFEE ATTORNEYS FLUID SENSING CUTTER CONTROL BACKGROUND OF THE INVENTION This invention is concerned with a class of applications wherein the arrival of a workpiece or work material at a machine is to cause the machine to take a specific action, and wherein the removal of the piece from the machine is to cause the machine to take a second specific action. The two specific actions may or may not be the same. Moreover, two sensors must be provided since the points at which the workpiece or work material arrives at the machine and departs from the machine may be different. An example of such a machine is a sewing machine to which may be brought a piece of material or a garment to the edge of which is to be sewn a binding. In such a case, the sensors are used to activate a shear which cuts the binding to a desired length. Two cuts per garment are needed since the position of each end of the binding with respect to the garment must be controlled.

Conventionally, electric eyes in pairs have been used for the above purpose. However, considerable vibration and shock are involved in the operations described, and it has been found that the reliability and the life of such optically controlled systems are inadequate. Moreover, in the attempt to increase the life and reliability of optical systems in the associated electronics systems, the introduction of sturdier components increases the bulk and weight of the control system to the point where it can no longer be used in combination with relatively small devices such as sewing machines.

SUMMARY OF THE INVENTION Pneumatic control systems are known to offer both long life and high reliability, in combination with compact size. Furthermore, highly reliable components of a relatively high degree of sophistication have become available at low cost as the result of the development of the science of fluidics. Such components have been found to serve the present purpose admirably.

The present invention may be exemplified in its use in combination with a sewing machine. More specifically, the invention is used to activate a shear when a garment is brought to the machine and to activate the shear for a second stroke when the garment is removed from the machine. The portion of the device which initiates the first cutting stroke comprises a first sensor jet and a detector jet. Both jets are located in the same plane and are related in the same sense as the stem and the cross bar of a T. In the absence of the sensor jet the detector jet would enter a receiver hole, but normally, the sensor jet intersects with and interferes with the detector jet so that air from the detector jet does not enter the receiver hole. However, introduction of a garment into the sensor jet abruptly interrupts the flow of the sensor jet and permits the detector jet to enter the receiver hole causing a sudden rise in pressure therein. This rise in pressure is transmitted through a pulse generator to a shuttle valve which activates the shear for a single stroke and return.

The device further comprises a second sensor jet and a second receiving hole. Introduction of the work material into the second sensor jet during the traverse of the sewing machine by the work material has no effect on the shear, since such an interruption causes a drop in pressure in the receiving hole and the device is designed so that it responds only to an increase in pressure. However, when the garment is removed from the second sensor jet, the sudden rise of pressure in the receiving hole then activates the shear.

It is an important feature of the present invention that the distance from each of the sensor jets to the shear can be individually adjusted. The adjustment over a suitable range may be either stepwise or continuous.

Accordingly it is an object of the present invention to provide a pneumatic device of high reliability and long like for the activation of equipment.

Another object of the invention is to provide such a device which activates equipment both on introduction of work material and on removal of work material.

A further object of the invention is to provide a pneumatic activation device having two stations, in which the distance from each station to the equipment to be activated is separately adjustable, either continuously or stepwise.

Still another object of the invention is to provide an improved pneumatic device for activation of equipment which is low in cost.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a schematic perspective representation of a sewing machine having a device in accordance with the present invention mountedthereon;

FIG. 2 is a partial elevational view of the device in which the equipment to be activated is a shear;

FIG. 3 is a partial sectional view taken along line 3- 3 of FIG. 2;

FIG. 4 is a partial sectional view taken along line 4 4 of FIG. 3;

FIG. 5 is a partial sectional view taken along line 5- 5 of FIG. 2;

FIG. 6 is a partial sectional view taken along line 6- 6 of FIG. 2;

FIG. 7 is a partial sectional view taken along line 7- 7 of FIG. 2;

FIG. 8 is a perspective view of a segmented shoe and block; and

FIG. 9 is a schematic diagram showing the system of air connections.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the device of the present invention generally designated as 1, is mounted in combination with a sewing machine 5. A block 3 is supported over the shoe 2. The work 4, in this case a garment to which an edge binding is to be applied is moved between the block 3 and the shoe 2 in the direction shown for the application of edge binding. In FIG. 2 the movable knife 6 combines with the fixed knife 7 to form a shear. The movable knife 6 rotates around the knife pivot 8; the block 3 is suspended by means of the bracket 9. Low pressure air is brought to the jets by means of the low pressure air supply hose 10. The pivot end of the high pressure cylinder 43 that operates the shear is shown at 11. A bellows valve which amplifies the pressure rise resulting from introduction of a jet into a receiver hole is shown at 12. The pulse generator 13 receives the output from the bellows valve and generates a single pulse which activates a shuttle valve 37 (FIG. 9) and, in turn, the shear.

Referring to FIGS. 3 through 6, a first sensor hole 14 emits a vertical sensor jet which passes in front of the detector hole 17 which is emitting a horizontal detector jet toward the receiving hole 19 in which is mounted the hose leading to the amplifier valve. An additional sensor hole 15 and an additional detector hole 18 are both blocked by pieces of tape 16. The air supply to both detector holes 17 and 18 is introduced through the hose 26 and the detector manifold 27. The sensor holes 14 and 15, the detector holes 17 and 18, and the receiver holes 19 and 21 make up the first station. The sensor hole 22, the additional sensor holes 23, which are blocked by the tape 16, the receiver hole 24 in which is mounted the hose 29 going to the amplifier valve, and the additional receiver holes 25 make up the second station. Normally, the sensor jet emanating from the first sensor hole 14 interrupts the detector jet emanating from the detector hole 17 so that the receiver hole 19 is essentially at atmospheric pressure. Introduction of a garment or other work material to interrupt the first sensor jet, results in the detector jet from hole 17 reaching the receiver hole 19 and causing a small pressure rise therein. This rise in pressure is taken through the hose 20 to a bellows amplifier, thence to a pulse generator and a shuttle valve and finally to a hydraulic cylinder which powers the shear through a cutting cycle and return to the rest position.

Advancement of the garment between the shoe and the block to the point where it interrupts the second sensor jet emanating from the hole 22 does not activate the shear since the system is sensitive only to an increase in pressure. However, when the garment is removed from above the hole 22, the jet once more enters the receiving hole 24 causing an increase in pressure which as before leads to a stroke of the shear.

To change the position of the first station and thereby the distance between the activation point and the shear, it is only necessary to transfer the tape 16 from the hole 15 to the hole 14 and from the hole 18 to the hole 17 and to transfer the tube 20 from the hole 19 to hole 21. A similar change in the position of the tape 16 at one of the holes 23 and a change in the location of the tube 29 in the receiving hole makes it possible to change the location of the second activating point. The changes in the first and second activation points can be carried out independently, of course, and, as is evident, the changes are made in steps.

FIG. 5 shows the means by which the low pressure air reaches the sensor holes of the first and second stations from the

hoses

30 and 31.

Referring now to FIG. 7, the location of the sensor hole 14, the detector hole 17, the receiver hole 19 and the hose 20 leading to an amplifier valve are shown. This view also shows the binding 32 which is to be applied to the garment.

FIG. 8 is a perspective view of the block and shoe so constructed as to make continuous adjustment of the various distance involved feasible. The shoe 2 consists of two

segments

20 and 2b which are slidable with respect to each other as a result of the tongue and groove connection 33. Similarly the block is also constructed in two segments 3a and 3b again joined by a tongue and groove arrangement. Segments 2a and 3a comprise the first station and segments 2b and 3b comprise the second station. In FIG. 8 the two parts of the second station are mounted rigidly with respect to each other by means of the bracket 34. The bracket 34 is held to the base 42 by the screws 36 in the slot 35. This arrangement makes it possible to shift the position of the second station without losing the alignment between the second sensing jet and the second receiver hole. A similar bracket, not shown, can be used to hold the segments of the first station in alignment.

FIG. 9 is a schematic diagram showing the pneumatic components and connections. Low pressure air is provided by the regulators 40 to

sensor jets

1 and 2 and to the detector jet. Normally the sensor jet No. l intersects the detector jet so that no impulse is received in the receiver hole of the first station. Interruption of the first sensor jet by the work material restores the detector jet which is received in the receiving hole; the resultant pressure rise is transmitted to the amplifier valve 41 and thence to the pulse generator 13, in turn to the shuttle valve 35 and finally to the pilot valve 38 which supplies high pressure air to the air cyclinder 39 which actuates the shear 6. When the work material is removed from the second sensor jet, the jet enters the receiver hole of the second station and the transmitted pressure rise traverses a second path similar to that described above, to actuate the air cyclinder and the shear.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific fea tures of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. Compact, adjustable, two-station pneumatic activation device, comprising a first sensing jet, a detector jet spaced from said first sensing jet and located perpendicular to and in the same plane as said first sensing jet so that said first sensing jet normally intersects said detector jet, a first receiver hole aligned to receive said detector jet, a first pulse generator connected to said first receiver hole and pneumatically connectable to equipment to be activated in a single operation cycle, a second sensing jet spaced apart from said first sensing jet, a second receiving hole aligned to receive said second sensing jet, and a second pulse generator, connected to said second receiver hole and pneumatically connectable to said equipment-to-be-activated in a single operation cycle, said pulse generators functioning in response to an increase in pressure in said respective receiver holes, whereby interruption of said first sensing jet by the introduction of work material between said sensing and detector jets causes operation of said equipment-to-be-activated, and restoration of said second sensing jet subsequent to interruption by work material causes operation of said equipment-tobe-activated.

2. Compact, adjustable, two-station, pneumatic, control device, comprising a shoe member having a longitudinal axis and a block member having a matching, parallel longitudinal axis, said block member being supported in registry with and spaced apart from said shoe member thus providing room therebetween for the introduction of work material, said shoe and block members each having a first and a second station spaced along said axes, said shoe member having at said first station a first sensor hole directed toward said block member, and connectable to a source of low pressure air to form a first sensing jet emanating from said first sensor hole, said block member in the region of said first station being generally U-shaped, with the opening of said U directed toward said shoe member, one leg of said U at said first station having a detector hole therein directed perpendicular to and in the same plane as said first sensor hole and being connectable to a source of low pressure air to form a detector jet emanating from said detector hole toward the other leg of said U, said other leg of said U having therein a first receiver hole aligned with said detector hole and being pneumatically connectable with equipment to be activated, one of said members at said second station having therein a second sensor hole directed toward the other of said members and connectable to a source of low pressure air to form a second sensing jet emanating from said second sensor hole, the other of said members having therein at said second station a second receiving hole aligned with said second sensor hole and being pneumatically connectable with said equipment-to-be-activated, and means for independently varying the distance between said first stations and said equipmentto-be-activated, and the distance between saidsecond stations and said equipment-to-be-activated.

3. Control device as defined in claim 2 wherein said shoe member and said block member are divided into a shoe first station segment, a shoe second station segment, a block first station segment and a block second station segment, said shoe first station segment and said block first station segment being mounted rigidly together, said shoe second station segment and said block second station segment being mounted rigidly together, said shoe first and second station segments being mounted slidably along said longitudinal axis with respect to said equipment to be controlled and said block first and second station segments being mounted slidably along said longitudinal axis with respect to said equipment to be controlled.

4. Control device as defined in claim 2 wherein said first shoe station has at least one additional first sensor hole spaced apart from said first sensor hole, along said [on 'tudinal axis, and parallel to said first sensor hole, sai additional first sensor hole being connectable to a source of low pressure air, means being provided for selecting a single first sensor hole through which the first sensor jet emanates, and wherein said first block station has at least one additional detector hole and at least one additional receiver hole spaced apart from said first detector and receiver holes by an amount and in a direction corresponding to the additional first sensor hole and being correspondingly connectable to a source of low pressure air and the equipment to be controlled, thereby achieving stepwise adjustment of the distance between the first station and the equipment to be controlled.

5. Control device as defined in claim 2 wherein said one of said members at said second station has therein at least one additional second sensor hole spaced apart from said second sensor hole along said axis and parallel to said second sensor hole, said additional second sensor hole being connectable to a source of low pressure air, means being provided for selecting a single second sensor hole through which said second sensor jet emanates, and wherein said other of said members at said second station has therein at least one additional receiver hole spaced apart from said second receiver hole by an amount and in a direction corresponding to said additional second sensor hole and being correspondingly connectable to said equipment to be activated, thereby achieving stepwise adjustment of the distance between the second station and the equipment to be activated.

6. Control device as defined in claim 1 wherein said equipment to be activated is a shear.

7. Control device as defined in claim 6 wherein said shear is mounted on and cooperates with a sewing machine.

8. Control device as defined in claim 6 wherein said shear, in response to the passage of said work material through said sensing jets cuts to a desired length a binding material applied to said work material.

9. Control device as defined in claim 5 further comprising a shuttle valve so arranged as to cause a single stroke and essentially immediate, subsequent retraction of said equipment-to-be-activated to a rest position as each pulse from said pulse generators is received.

10. Control device as defined in claim 2 wherein said one member is a said shoe member and said other member is said block member.

Claims

1. Compact, adjustable, two-station pneumatic activation device, comprising a first sensing jet, a detector jet spaced from said first sensing jet and located perpendicular to and in the same plane as said first sensing jet so that said first sensing jet normally intersects said detector jet, a first receiver hole aligned to receive said detector jet, a first pulse generator connected to said first receiver hole and pneumatically connectable to equipment to be activated in a single operation cycle, a second sensing jet spaced apart from said first sensing jet, a second receiving hole aligned to receive said second sensing jet, and a second pulse generator, connected to said second receiver hole and pneumatically connectable to said equipment-to-be-activated in a single operation cycle, said pulse generators functioning in response to an increase in pressure in said respective receiver holes, whereby interruption of said first sensing jet by the introduction of work material between said sensing and detector jets causes operation of said equipment-to-be-activated, and restoration of said second sensing jet subsequent to interruption by work material causes operation of said equipment-to-be-activated.

2. Compact, adjustable, two-station, pneumatic, control device, comprising a shoe member having a longitudinal axis and a block member having a matching, parallel longitudinal axis, said block member being supported in registry with and spaced apart from said shoe member thus providing room therebetween for the introduction of work material, said shoe and block members each having a first and a second station spaced along said axes, said shoe member having at said first station a first sensor hole directed toward said block member, and connectable to a source of low pressure air to form a first sensing jet emanating from said first sensor hole, said block member in the region of said first station being generally U-shaped, with the opening of said U directed toward said shoe member, one leg of said U at said first station having a detector hole therein directed perpendicular to and in the same plane as said first sensor hole and being connectable to a source of low pressure air to form a detector jet emanating from said detEctor hole toward the other leg of said U, said other leg of said U having therein a first receiver hole aligned with said detector hole and being pneumatically connectable with equipment to be activated, one of said members at said second station having therein a second sensor hole directed toward the other of said members and connectable to a source of low pressure air to form a second sensing jet emanating from said second sensor hole, the other of said members having therein at said second station a second receiving hole aligned with said second sensor hole and being pneumatically connectable with said equipment-to-be-activated, and means for independently varying the distance between said first stations and said equipment-to-be-activated, and the distance between said second stations and said equipment-to-be-activated.

4. Control device as defined in claim 2 wherein said first shoe station has at least one additional first sensor hole spaced apart from said first sensor hole, along said longitudinal axis, and parallel to said first sensor hole, said additional first sensor hole being connectable to a source of low pressure air, means being provided for selecting a single first sensor hole through which the first sensor jet emanates, and wherein said first block station has at least one additional detector hole and at least one additional receiver hole spaced apart from said first detector and receiver holes by an amount and in a direction corresponding to the additional first sensor hole and being correspondingly connectable to a source of low pressure air and the equipment to be controlled, thereby achieving stepwise adjustment of the distance between the first station and the equipment to be controlled.