US2252560A - Wire strapping tool - Google Patents

Description

4 Sheets-Sheet 1 H. EMBREE WIRE STRAPPING T001.-

Filed April 25. 1959 Aug. 12, 1941.2

INVENTO 1 (IIIIIII m 7 6 k W F h ATTORNEY-S H. EMBREE WIRE STHAPPING TOOL Aug. 12, 1941.

Filed April 25, 1939 4 Sheets-Sheet'S INVENTER BY JVML Ah'oRNEYs g- 12, 1941- H. EMBREE 2,252,560

' WIRE STRAPPING TOOL I Filed April 25, 1939 4 Shets-Sheet 4 uni/1 m lg- INVENTOR lf 'apnromuxzvs Patented Au .12, 1941 WIRE STBAPPING TOOL Herbert Embree, Hamilton, Ontario, Canada, assignor to Griplock, Inc., New York, N. Y., a corporation of Delaware Application April 25, 1939, Serial No. 269,883

5 Claims.

This invention relates to a wire Strapping tool designed for fastening wire straps or the like around packages. It is well adapted for use with straps such, for instance, as those shoum in U. S. Patent to W. N. Lurcott No. 1,474,372, granted, November 20, 1923, in which one end of the strap is coiled back on the body and the knot or gripping formation is made by inserting the other end of the strap'through the said coiled portion and then crushing or flattening the coiled portion so as to deform the contacting parts into an interlocking en agement; but theinvention is not limited to use in connection with any particular form of strap as it. has general adaptability for the knotting of straps by a pressing or crushing operation.

The invention has for an object to provide such a tool which is hydraulically operated so as to insure uniformity and precision in the knotting or crushing operation at all times. Another object consists in providing such a tool which is instantaneous in operation and requires no substantial physical efiort on the part of the operator.

Another object consists in providing such a tool that includes means for maintaining a suitable temperature of the actuating fluid, e. g. oil.

Another object consists in providing such a tool that includes means for maintaining a given operating pressure in order to prevent either failure of operation or operation under excessive force.

Another object consists in providing such a tool in which there is normally a continuous flow of the operating fluid, and in which actuation of the knotting or crushing means takes place'by'interrupting said flow.

Another object consists in providing such a tool in which the main bulky or weighty portion may remain in a fixed position, while the knotting or crushing means is comparatively small and light Fig. 2 represents a perspective view of the same looking in a direction opposite to Fig. 1;

Fig. 1 represents a perspective view of the whole tool;

Fig. 3 represents an enlarged detail section, partly in elevation, of the pump and associated parts, taken substantially in the plane of the line lII--III of Fig. 4, looking in the direction of v taken substantially in the plane of the line'V-V of Fig. 3, looking in the direction of the arrows;

Fig. 6 represents a. detail transverse section taken substantially in the plane of the line VI-VI of Fig. 3, looking in the directionof the arrows;

Fig. 7 represents a similar view taken substantially in the plane of the line VII--V1I of Fig. 3

looking in the direction of the arrows;

Fig. 8 represents a diagrammatic view showing the valve arrangement and flow of the operating of the knot- Fig. 12 represents a detail section taken substantially in the plane of the line X[IXII of Fig. 10. I I

Generally speaking the tool comprises pumping mechanism and knotting or crushing mechanism, the two being in operative connection.

The pumping mechanism is chiefly represented in Figs. 3 to 8, and includes an electric motor I that ismounted on a suitable base 2 and secured in position by cap screws or the like, two of which areshown and marked 3. The motor acquires its power through cable 4 from a suitable source of energy (not shown) in any well known or approved manner.

The motor shaft 5 has a fly wheel 6 fixed thereon, and "a sprocket I is fast to the hub of the fly wheel. A sprocket chain8 connects sprocket I with another, and larger, sprocket 9 that is fastened by screws ill to the flange of a hub Ii that is keyed to a shaft l2 and held in position onthe end of the shaft by a washer l3 and screw H. A

suitable housing or covering l5, which is screwed to a vertical wall l6, serves to encase the sprockets and chain.

As a result of the mechanism just described, it will be clear that operation of the motor I will drive the shaft l2 at a reduced'speed as compared with that of the motor shaft. 5.

The shaft I2 is rotatably mounted in ball bearings I1, I1 that are positioned against movement toward each other by a spacing tube I8 and by shoulders in a sleeve I9; while a, packing gasket 28 and the crank head 2| that is keyed onto the inner end of shaft I2 hold the said bearings firmly against tube I8 and the shoulders in sleeve I9. The sleeve I9 is preferably formed integral with the vertical wall I6.

The crank head 2| carries an eccentrically mounted pin 22 which is set into a block 23 that is fitted to reciprocate vertically between piston heads 24, 25 for reciprocating the latter as shaft I2 and its crank head 2| rotate, for a purpose to be hereinafter described.

cylinder 26 that forms one branch of a T-shaped' casting which is suitably supported on abase that is preferably cast integrally therewith and is denoted in general by 21, Fig. 1. The end of cylinder 26 is secured to vertical wall I6, as by screws,

one of which is shown and marked 28.

The piston heads 24, 25 are formed in one piece, being connected by web 29, as is best shown in Fig. 5, and they carry long slender pistons 38, 3|, which have their inner ends flanged and set in recesses formed in piston heads 24, 25, wherein they are rigidly secured by clamping plates 32', 33, which are fastened to piston heads 24, 25 by screws, two of which are marked 34, 35.

As already mentioned, cylinder 26 forms one branch of a T-shaped casting, and it will be observed, by particular reference to Fig. 3, that the remainder of the said casting consists of an elongated double cylinder denoted by 36, in which the piston heads 24, 25 reciprocate under the influence of shaft I2.

In the ends of double cylinder 36 are fitted plugs 38, 39, which are centrally bored to form chambers 49, 4|, in whichpistons 38, 3| have a close sliding fit in order to function therein by alternate compression and suction, as in the case of the usual combination of piston and cylinder.

Plugs 38, 39 are flanged and secured by screws to double cylinder 36, certain of the screws being shown and marked 42, 43. The said plugs are also provided with bores 44, 45 that house valves 46, 41 which find seats at the outer ends of the said bores and are yieldingly held on their seats by expansion coiled springs 48, 49 that abut plates 58, which are secured by cap screws to plugs 38, 39, certain of the cap screws being shown and marked 52, 53, Fig. 5. It will be seen that the valves 46, 41 are so arranged as alternately to lift from their seats when pistons 38, 3| move so as to exert a suction in bores 44, 45, which latter are in communication with piston bores 48, 4|, through passages 54, 55.

The plugs 38, 39 are provided'with two more bores 56, 51, Fig.5, in which are fitted valves 58, 59 that are held to seats formed at the inner ends of said bores by compression springs 68, 6| located in recesses 62, 63 which are in line with bores 56, 51 and are connected ,by a tube 64. Washers 65, 66, fitted at the ends of tube 64, serve, as abutments for springs 68, 6|. As a result of the, arrangement just described, it will be clear that, when a compressive effect is exerted in bores 56, 51, the valves 58, 59 will lift from their seats and open communication from bore 56 to bore 51. Such compressive effect is alternately obtained by the reciprocation of pistons 38, 3| because the bores 48, 4|, in which the pistons reciprocate, are connected with bores 56, 51 by the passages 54, 55-.

The plug 39 is further provided with a recess 61 that is adapted to receive a valve casing 68 which has, its inner end equipped with a conical valve tip 69 that finds a seat in an angular passage 18 formed in plug 39, which passage opens into recesses 61 and 63 so as to establish communication therebetween. The wall of valve casing 68 has a port 1| formed therethrough, which opens communication between recess 61 and a free space lying between plug 39 and the wall of double cylinder 36 adjacent to valve casing 68, which free space is denoted by 12 and serves as a bypass, as will be hereinafter described. The valve casing 68 is fitted to slide in recess 61 and is normally held in the position shown in Fig. 3, in which valve tip 69 is seated to close passage 18 and the casing itself closes port 1|, by an expan'slon spring 13 that abuts an adjustable screw plug 14 so as to provide for variation in the pressure exerted by spring 13 to keep valve tip 69 seated. The construction just described provides a safety valve which is effective in the sequence of operations of the apparatus, as will be herein- I after described, to counteract excessive pressure built up during the crushing or knotting operation.

Plug 38 has an angular conduit 15 formed therein which communicates at one end with the recess 62 and opens at the other end through plate 58 for connection with a hose pipe 16 that runs to the operative head of the apparatus, as will be hereinafter set forth. Another hose pipe 11 also communicates with the operating head and, to complete the circuit, is connected at 18, Fig. 2, with a radiator that is in communication with the main body of the apparatus, as will be explained.

In order to insure proper alignment of the motor I, the base 2, on which it is mounted, is adjustably supported by bolts 19, 19 which are set in bosses 88, 80, formed on the double cylinder 36, and by cap screws 8|, 8| thatare threaded into the wall I6 and traverse slotted lugs 82, 82 depending from base 2.

Turning now to the operative head of the apparatus which includes the mechanism for knotting or crushing the wire strap, it comprises a hollow casing 83 that carries a reciprocating plunger 84 which has an enlarged piston head 85 that is provided with a gasket 86 held in position by a clamping washer 81 which is fixed to head 85 by screw 88. The upper part of the hollow casing 83 is sealed by a screw plug 89 which also has a gasket 98 fixed in position by washer 9| and screw 92'.

The wall of casing 83 has an angular passage 93 formed therein which opens by port 94 into the casing 83 intermediate the reciprocable plunger 84 and the screw plug 89.

The angular passage 93 traverses a screw threaded boss that is formed on casing 83 and mates with a coupling 95 that is threaded into the channel 96 of a neck piece 91 which, in turn, is connected by a coupling 98 with the hose pipe 16 that is in communication, as hereinabove described, with conduit 15 in plug 38.

Neck piece 91 has a cylindrical chamber 99 formed therein which is in open communication with the channel 96 by means of a port I88. One end of the said chamber is connected by a hollow screw plug IOI with hose pipe 11, and the other end is closed by a screw plug and gland which are together marked I82. A perforated .valve piston I83 is fitted to slide in chamber 99 and is normally urged by spring I84 to the position shown in Fig. 10. The rod of piston I83,

which is marked I05, is pivotaily connected at I06 to a valve operating lever that is, itself, pivoted at M1 on neck piece 91 and has a grip I08 for manual operation. Figures and 11 show the valve mechanism just described in two positions, the normal position in Fig. 10 being such that the piston I03 permits communication beposition shown in Fig. 10, because it is alsofree tween hose pipes I6 and II, by way of port I00,

and perforations I08 through piston I03, while the manually altered position, shown in Fig. 11,

closes communication between the said hose pipes by moving piston I03 so. as to cover port crushing block IIO which is secured in position by a conventional-form of dovetailed lock that The lower end ofplun'ger 84 carries a hardened is operated by screw III. The said crushing block also carries a blade H2 and the block and cutter cooperate with a hardened anvil and cutting block II3 which latter is supported by a foot I I4 that is cast integral with casing'83. Two expansion coil springs, one of which is shown and marked I I5, are housed in plunger 84 and abut a shoulder I I6 formed in casing 83 so as normally to urge the plunger into its upper or inoperative position illustrated in Fig. 10. The crushing and cutting-or operative position of the plunger, is shown in Fig. 11.

When in use the spaces in the three-part castingcomprising the cylinder 26 and double cylinder 36 are filled with a fluid which can operate on a hydraulic principle; such, for instance, as

light motor oil; and, to assure an abundant supply of the said fluid, a reservoir I I1, Fig. '4, is set into the end of cylinder 26 opposite the sprocket 0 and is secured in position by screws IIB. A filling cap II 8 is provided in the top of the reservoir and, in order to prevent overheating of the oil, a radiator I20, which is preferably similar to an automobile radiator, is fixed to the reservoir as indicated at I2I, I2I.

The upper part ofthe radiator is connected at'I22 by a hose I23 with the reservoir III as indicated at I24. 'A fan 2 pipes I6, 11 and I23, so that, when the operating head valve mechanism is in the normal position represented-in Fig. 10, there is a complete circulation of the fluid through all said parts of the' apparatus under the influence of the pumping action of pistons 30, 3 I

Describing now the operation of the apparatus, it may be said that the parts just mentioned are normally filled with light motor 'oilor other suitable fluid and the motor is set in operation. The diagrammatic view shown in Fig. 8 of the drawings is helpful for an understanding of the operation'and it may be said that the port therein shown as piercing the wall of double cyl-' inder as, which port is marked I26, is a diagrammatic representation of the connection of hose pipe 11 with radiator I at the point T8.

In Fig. 8, the pistons 30, 3| are shown in their extreme position at the right so that piston is on its compression stroke and piston 3| on its suction stroke. The effect of piston 30 is indicated by the arrows, and it-will be seen that it serves to drive the fluid out of chamber to pass through port I00, chamber 99,- perforated valve piston I09, and hose pipe Tl, back to connection I8 on radiator I20, which connection, as previously mentioned, is represented at I 26 in the diagrammatic showing of Fig. 8.

At the same time that the pumping effect just described is taking place under the compression effect of piston 30, the suction eflect of piston 3| is drawing oil from the reservoir and cavities of the cylinders 26 and 36, as'indica'ted by the arrows at the lower left part of Fig. 8, through bore 45, past valve 41, and through passage into chamber 4I.

When, now pistons 30 and 3| move to the left in Fig. 8, piston 3| acts on its compression stroke and forces the fluid out of chamber 4I, through passage 55, into'bore 51, past valve 59, through recess 53, through tube 64, through recess 62 and through conduit I5 into hose pipe I6. This action of thepistons, which opens valve 59, likewise closes valve 58, so as to require the fluid to move from recess 62 into conduit 15; and it also closes valve 41 so as to prevent any forcing of the fluid back into the spaces within cylinder 36.

Thus, under normal conditions, when the operating head is not in use, the pumping action of pistons 30 and 3| maintains a continuous flow of oil or other suitable fluid as just described without generating any substantial amount of hydraulic pressure.

a When it is desired to actuate the operating head, it is only necessary for the operator to squeeze the grip I08 so as to move the connected valve mechanism into the position shown in Fig. 11, wherein valve piston I03 closes port I 00, This will prevent return circulation of the fluid through hose pipe I1 and its connections, and will cause the pumping apparatus to build up bydraulic pressure in the hose pipe I6 and connected parts, which pressure will be exerted in casing 83 of the operating head upon plunger 84 so as to force the latter from the position shown in Fig. 10 to the crushing and cutting position shownin Fig. 11. This operation, including the generation of very high pressure, such, for instance, as twelve thousand pounds per square inch, takes place instantly uponactuation of the grip I08 and, as soon as the wire strap I2I has been deformed from the shape shown in Fig. 10 to that shown in Fig. 11, and the excess portion severed .(all as is well understood in this art), the operator merely releases the grip I08, which permits spring I04 to move piston valve I03 to the position shown in Fig. 10. This releases the high pressure previously generated and reestablishes circulation between hose pipes I6 and H with their connected parts thereby removing pressure in casing 83 of the operating head;

whereupon spring II5 returns plunger 84 to its elevated position, and the apparatus is in condition for operation upon another wire strap.

The high pressure generated by operating the hand grip I08 so as to cause piston valve I03 to close port I00 is regulated by safety valve 68 which is normally seated, as shown in Figs. 3 and 8, so asto close communication between angular passage I0 and recess 61. Should, however, the hydraulic pressure become sufiicient to overcome the power of spring I3 that controls safety valve 68, tip 69 of the latter will be unseated from passage I due to thempressure of fluid in the latter, whereupon the compression stroke of piston 3|, instead of forcing the fluid only through tube 64 and parts leading thereto, will also force the fluid through passage I0, recess 51, port II, by

pass I2, back into the space within cylinder 36, as indicated by the arrow at the upper left hand part of Fig. 8, in which space there is very little pressure. Thus it will be clear that, by adjusting the tension of spring I3, a predetermined, uniform hydraulic pressure may be attained upon each use of the apparatus, and accidental excess pressure will be avoided.

In'actual use, the apparatus is stationed adjacent the point at which the packages are to be strapped and the motor I is started so as to actuate the pistons 30, 3I of the pump, which actuation causes the fluid to circulate from conduit I5 of the pump through hose pipe 16, coupling 98, channel 96,- port I00, chamber 99, perforated piston I83, and hose pipe 'I'I back to radiator I29 at the connection 18, which last named connection is diagrammatically represented by I26 in Fig. 8. The details of the operations and parts by which the pistons 30, 3| generate and maintain this circulation have been hereinabove set forth at length and need not be'repeated.

The operator now passes a strap around a package with its ends in overlapping position suitable for the crushing or tying step, and the operating head 83 is manually positioned so that its foot, I I4 passes under the overlapped ends of the strap I2I, as illustrated in Fig. of the drawings, with the crushing block I II] and blade I I2 immediately thereabove. The grip I08 is then manually operated so as to move it from the position shown in Fig. 10 to that shown in Fig. 11 which causes piston I03 to close port I09 and stop the fluid circulation just described. This stoppage causes the pistons 30, 3I instantly to generate a very high hydraulic pressure, as hereinabove described, and

to force the fluid powerfully through hose pipe I6, coupling 98, channel 96, coupling 95, passage 93, and port 94, into the operative head casing 83 above piston head 85, which latter is thereby forced downwardly so as to perform the crushing and severing operation upon the strap. The operator thereupon releases the grip I08 so that it is automatically returned by spring IM to the position represented in Fig. 10 which reestablishes the substantially pressureless circulation of the fluid above described and simultaneously releases the pressure on piston head 85 so that it and the crushing block and blade carried thereby are returned by springs II5 to the elevated position shown in Fig. 10. With the parts in this position, the operative head is removed from the strapped package and is ready for use in connection with another package and strap, in which case the manner of use hereinabove described will be repeated.

From this brief recitation of the manner practical use of the apparatus it will be seenthat the pumping mechanism need not be moved and that it is normally idling so as to induce a substantially pressureless circulation of the hydraulic fluid through the parts of the apparatus other than the operating head. The said head is readily brought into cooperative position with respect to the package and strap because of itscomparatively small size and light weight as well as the and, by the simple operation of a hand lever, the substantially pressureless circulation is instantaneously changed to very powerful hydraulic pressure that is exerted within the operative head for the desired operation upon the strap. Release of said lever simultaneously releases said pressure and all parts are restored to their normal positionswith the pump idling under substantially pressureless circulation.

It will be observed that this apparatus or tool is suited for uses in which only a small space is aiforded for the tying or crushing operation, because the main body of the apparatus, including the pumping mechanism, may stand in any convenient place and the head or tool proper be carried in the hand of the operator to the point of its application to knot the strap, because of the length and flexibility of the hose pipes I6, 'I'I which, of course, may be of any desired. length.

In view of the fact that the apparatus is principally designed for the strapping of material that is placed in a press before the strapping operation, thereis no occasion for providing strap tensioning mechanism, because, when the strapped material such, for instance, as a pile of pulp board, is released from the press, it expands sufiiciently to bring about the desired tightness or tension of the strap. Consequently, it is ,only necessary to place the strap around the compressed material with its extremities in knotting position, and then bring the operating head of the tool into crushing relationship with the strap, as indicated in Figs. 10 and 11, whereupon the grip valve may be operated and the knot formed. It is evident that this may be done without moving either the main body of the apparatus or the material to be strapped, and that the small size of the operating head enables it to be'used in places where the operation of a hand tool or the like would'be either impossible It should be noted, however, that the tool is adapted for the strapping of materials that are not held in a press, since it will cooperate with any suitable form of tensioning mechanism by knotting straps that have been tensioned. Indeed, as mentioned at the outset, the tool is useful in connection with the knotting of any form of strap where the operation is performed by pressure, because it is only necessary to alter the form of the crushing block and anvil to suit the occasion whether it call for a mere crushing, or a bending, or a punching operation, or any combination of these.

Owing to the provision of means .for adjusting the power of the safety valve spring, any reasonable desired hydraulic operating pressure may be generated, so that every strap will be knotted or crushed to the same uniform extent throughout the day and from day to day. This, of course, is not true in the case of mechanically operated tools that depend upon the strength and length and flexibility of the hose pipes I6, 11,

care exerted by the operator. Furthermore, the crushing or knotting is performed with great rapidity as compared with a hand operated tool; so that this improved apparatus or tool constitutes a marked step in advance from the point of view of efiectiveness, uniformity, speed and convenience, not to mention other attributes inherent in the structure and mode of operation.

It will be understood that various changes may be resorted .to in the form, construction and arrangement of the several parts without departing from the spirit and scope of my invention, andhence I do not intend to be limited to the details 1. A wire strapping tool for sealing and sev-' ering straps placed around packages comprising, a manually portable and operable head having sealing and severingmechanisms', a stationary means for generating hydraulic power to operate said mechanisms, a flexible conduit connecting ,the head and the stationary means to permit the head to be manually brought into operable relationship with a strap placed around a package and toprovide for circulation of the hydraulic medium through the stationary means and the head, and amanually operable valve carried by the head for actuation by the operator after the head has been manually brought into operable relationship with a strap placed around a package to cause the hydraulicmedium to activate. the sealing and severing mechanisms.

2. A wire strapping tool for sealing and severing straps placed around packages comprising, a manually portable and operable head having sealing and severing mechanisms, a stationary means for generating hydraulic power to operate said mechanisms, a flexible conduit connecting the head and the stationary means to permit the head to be manually brought into operable relationship with a strap placed around a package and to provide for circulation of the hydraulic medium through the stationary means and the head, and a manually operable valve carried by the head for actuation by the operator after the head has been manually brought into operable relationship with a strap placed around a package to cause the hydraulic medium to activate tion with the head and through the valve when the tool isnot in operation to permit the hydraulic medium to circulate at sub-operating pressure, and the valve being arranged to close communication therethrough when it is manually actuated to obstruct the said circulation of the hydraulic medium and cause an instantaneous great increasein pressure for activating thesealing and severing mechanisms.

4. A wire strapping tool for sealing and severing straps placed, around packages comprising, a manually portable and operable head having sealing and severing mechanisms, a stationary means for genertaing hydraulic power to operate said mechanisms, a flexible conduit connecting the head and the stationary means to permit the head to be manually broughtinto operable 1 relationship with a strap placed around a packthe sealing and severing mechanisms, said head being relatively small and light with respect to said, stationary means to enable the operator to seal and sever straps at pointsthat would be inaccessible and impractical if the head included the power generating means. I

3. A wire strappingtool' for sealing and severing straps placed around packages comprising, a manually portable and operable head having sealing and severing mechanisms, a stationary carried by the head for actuation by the oper ator after the head has been manually brought into operable relationship with a strap placed around a package to cause the hydraulic medium to activate the sealing and severing mechanisms, said flexible conduit being in open communicaage and to provide for circulation of the hydraulic medium through the stationary means and the head, a manually operable valve carried by the head for actuation by the operator after the head has been manually brought into operable relationship with a strap placed around a package to cause the hydraulic medium to activate the sealing and severing mechanisms, and

means in open circulating communication with the head, the conduit and the power generating means for controlling the temperature of the hydraulic medium as it is circulated therethrough.

5. A wire strapping tool for sealing and severing straps placed around packages comprising,

a manually portable and operable head having sealing and severing mechanisms, a stationary means for generating hydraulic power to operate said mechanisms, a flexible conduit connecting the head and the stationary means to permit the head to be manually brought into operable relationship with a strap placed around a package and to provide for circulation of the hydraulic medium through the stationary means and'the head, a manually operable valve carried by the head for actuation by the operator after the head has been manually brought into operable relationship with a strap placed around a package'to cause the hydraulic medium to activate the sealing and severing mechanisms, said flexible conduit being in open communication with the head and through the valve when the tool is not in operation to permit the hydraulic medium to circulate at sub-operating pressure, and the valve being arranged to close communication therethrough when it is manually actuated toobstruct the said circulation of the hydraulic medium and cause an instantaneous great increase in pressure for activating the sealing and severing mechanisms, and means for preventing a too great increase in said pressure.

HERBERT EMBREE.

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