US2938453A - Power press - Google Patents

Description

May 31, 1960 w. F. GOLDING POWER PRESS 2 Sheets-Sheet 1 Filed Feb. 11, 1958 3 M e T F 7 M m 2 m 2 W 2 0 9 K n 9 3k a C 5S3 m \V/ a a a H2 l May 31, 1960 w. F. GOLDING POWER PRESS 2 Sheets-Sheet 2 Filed Feb. 11, 1958 FIG.2

United States Patent POWER PRESS William Frank Golding, 22, Parrys Close, Stoke Bishop, Bristol 9, England Filed Feb. 11, 1958, Ser. No. 714,558

Claims priority, application Great Britain Feb. 15, 1957 '4 Claims. (Cl. 100-257) This invention relates to power presses of the kind comprising a reciprocable platen situated between a reaction member and a fixed platen connected thereto, the reciprocable platen being actuated for its movement by link means including a link pivotally seated on a seat provided on' the reaction member.

The main object of this invention is to provide im proved means for adjusting the spacing or daylight between the platens.

According to this invention I provide a press comprising a reciprocable platen situated between a reaction member and a fixed platen connected thereto, the reciprocable platen being actuated for its movement by link means including a link pivotally seated on a seat provided on the reaction member characterized in that the seat comprises a seat member connected to the reaction member by a screw means for varying the distance between the seat member and the reaction member and thereby varying the daylight of the platens.

The screw means may comprise a screw-threaded bolt attached to the seat member and engaging a nut seated for rotation in the reaction member. The nut may be adapted to be rotated through the intermediary of worm gearing. Two such screw means may be provided for the seat member and in this case, as well as in the case where more than one set of link means are employed, all the nuts may be adapted to be rotated jointly operated by a single operating member.

Particularly in the case of upstroke presses, it has been found that in some cases the end thrust between the nuts and the reaction member causes an undue frictional resistance againstrotation of the nut. It is of course possible to introduce a ball thrust bearing between the nut and the reaction member but this may not be desirable because this beating would unavoidably have to take the working pressure of the press during the operation thereof whereas it is only required to take the weight of the reciprocable platen at the time when the latter has to be adjusted for daylight.

To overcome this difiiculty a press according to this invention may include resilient means for raising the nuts from their seating surfaces on the reaction member, antifriction bearings being interposed between the resilient means and the nuts.

One form of press according to this invention will now be described with reference to the accompanying drawings wherein:

Fig. 1 is a partly sectioned side elevation of a toggle press.

Fig. 2 is a plan view of Fig. 1 sectioned on the line II-II in Fig. 1.

Fig. 3 is a sectional detail of Fig. 1 shown at an enlarged scale.

Fig. 4 is a section on the line IVIV in Fig. 3.

Referring to the drawings the press comprises a reaction member or base 1, an upper platen 2 fixed to a frame (not shown) of the press, and a lower platen 3 situated between the base 1 and the upper platen 2. The platen 3 2,938,453 Patented May 31, 1980 1 comprising an upper link 5 and a lower link 6. The

toggle sets 4 are positioned substantially at the four corners of the platen 3, the latter being of rectangular shape. The links 5, 6 of each set 4 are pivotally connected together by a pin 31 connected to a crank shaft 32 by a connecting rod 33, rotation of the crank shaft 32 operating to flex the links 5, 6 and thereby to operate the platen 3.

The lower link 6 of each set 4 is pivoted at its bottom end by means of a pin 7 to a foot member 8 to which are secured two screw-threaded bolts 9 each engaging a nut 10 seated in the base 1. Each nut 10 comprises a cylindrical body 11 seated for rotation in a bore 12 of the base 1, the bore 12 having an end face 14 opposite the bottom end face 13 of the body 11. The end face 13 defines a pressure surface, and the end face 14 defines a supporting surface for said pressure surface. The bore 12 is extended from the face '14 by a coaxial smaller bore 15 in which is seated for axial sliding motion an abutment or sleeve 16 closed at its upper end by a head. portion 17. The sleeve 16 contains a coaxial bolt 18 extending axially slidably through a hole in the head portion 17. The bolt 18 is provided with a stop or top end collar 19 seated on top of the head portion '18 and with a bottom end collar 20 abutted by a spring 21 situated in a state of compression between the end collar 20 and the underside of the head portion 17. The collar 20 is seated on a stop member 22 screw-threaded into the base 1 for adjustment of the stop position. is provided with recesses 23 for access to the stop members 22 for the adjustment thereof.

Between the sleeve 16 and the face 13 of the body 11 there is provided an anti-friction thrust bearing 24 being a ball or roller thrust bearing.

Each of the cylindrical bodies 11 is formed in the circumference thereof with worm wheel teeth 25 engaged by a Worm 26. The worms 26 related to the toggle sets 4 situated on the one side of the press are provided on a common shaft 27, and the Worms 26 on the other side of the press are provided on a common shaft 28, the shafts 27, 28 being journalled in the base 1 and connected by a chain drive 29. The shaft 27 has secured thereto a hand wheel 30.

In operation, the daylight between the platens 2, 3 is adjusted by rotation of the hand wheel 30 which causes all the foot members 8 to be jointly raised or lowered. The springs 21 are such that their combined strength is capable of lifting the platen 3 whereby the faces 13, 14 are caused to part and the load of the platen 3 is taken by the bearing 24. The resulting clearance between the faces 13, 14 is indicated to an exaggerated extent at 31, Fig. 3. The parting of the faces 13, 14 is limited by the collar 19 which is so positioned that the parting of the faces 13, 14 is not substantially more than is necessary to avoid frictional contact between them.

. When the press is operated the working pressure between the platens causes each spring 21 to be compressed until the faces 13, 14 touch, and the latter than take the working pressure of the press.

The advantage of the press described hereinabove resides in that for the rotation of the nuts 10 the friction between the surfaces 13, 14 is avoided and that the weight of the platen is taken by the bearings 24 whose resistance is of course virtually zero.

In a modification (not illustrated) the sleeve 16, bolt '18 and spring 21 are dispensed with. In this case the frictional resistance between the faces 13, 14 may be overcome by the introduction of a ball or roller bearing disposed directly between the faces 13, 14, but such a bearing would of course have to be strong enough not The base 1.

ares-ate only to take the weight of the platen 3 but also to take the working pressure of press.

What I claim and desire to secure by Letters Patent is:

l. A press comprisinga movable platen situated between a reaction member and a fixed platen, a toggle connected at one end to the movable platen and at the other end to the reaction member and flexing of the toggle operating to reciprocate the movable platen relative to the fixed platen; the connection of the toggle to thereaction member comprising a screw to which said other end of the toggle is connected, a nut engaging the screw and supported for rotation on the reaction member, one end of the nut defining apressure surface situated face to face with a supporting surface provided on the. reaction member and intended to support the nut against axial movement under the working pressure of the press, an anti-friction thrust bearing situated between the nut and an abutment provided on the reaction member, the bearing being positioned to transmit a load from the nut to the abutment in the direction of the working pressure of the press, and means for moving the abutment in a direction opposite to that of said working pressure thereby to unseat the nut from its supporting surface on the reaction member, the supporting surface and the abutment defining alternative means for supporting the nut on the reaction member, rotation of the nut operating to adjust the daylight between the platens and the abutment being intended to support the nut only when the latter is to be rotated for said daylight adjustment.

2. A press comprising an upper fixed platen, a lower platen, a reaction member situated below the lower platen, an operating member mounted on the reaction member for rotation about a vertical axis and including a vertical screw thread, a non-rotatable seat member provided with a screw thread engaging the screw thread of the operating member, means connected between the seat member and the lower platen for reciprocating the lower platen relative to the upper platen and the seat member cooperating to seat said means on the reaction member through the intermediary of said operating member and rotation of the latter operating to adjust the daylight between the platens, the reaction member-being dimensioned to define a supporting surface positioned to support the operating member against axial downward movement, means for raising the operating member from said supporting surface thereby to break frictional contact therebetween, said raising means including an anti-friction bearing positioned to support the operating member for rotation and against axial downward movement and the raising means operating upon actuation thereof to support the operating member through the intermediary of said bearing thereby to provide a relatively frictionless support for the operating members for use during the adjustment of said platen daylight.

3. A press according toclaim 2, said raising means comprising a resilient member situated between said anti friction bearing and said reaction member thereby to urge said bearing upwardly against said operating member, the strength of the resilient member being selected so that the operating member is raised from said supporting surface when said platens are parted during the reciprocation of said lower platen but that the resilient member is compressed and the operatingme'mber is seated on said supporting surface when the platens engage and the working pressure between them is transmitted through said operating member onto saidresilient member.

4. A press according to claim I, wherein the means for moving the abutment comprise a spring situated between the abutment and a stop provided on the reaction member, a further stop being positioned to limit the movement of the nutunder the action of the spring, the spring having a strength less than is necessary to resist the working pressure of the press but greater than any load on the nut when said working pressure is absent.

References Cited in the file of this patent UNITED STATES PATENTS

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