US3672242A - Crank with adjustable crank radius - Google Patents

Crank with adjustable crank radius Download PDF

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Publication number
US3672242A
US3672242A US51744A US3672242DA US3672242A US 3672242 A US3672242 A US 3672242A US 51744 A US51744 A US 51744A US 3672242D A US3672242D A US 3672242DA US 3672242 A US3672242 A US 3672242A
Authority
US
United States
Prior art keywords
crank
ram
thrusting
pressure fluid
rotation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US51744A
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English (en)
Inventor
Manfred Fritz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schloemann AG
Original Assignee
Schloemann AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Schloemann AG filed Critical Schloemann AG
Application granted granted Critical
Publication of US3672242A publication Critical patent/US3672242A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
    • F15B7/003—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors with multiple outputs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
    • F15B1/02—Installations or systems with accumulators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
    • F15B7/005—With rotary or crank input
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/21—Elements
    • Y10T74/2173—Cranks and wrist pins
    • Y10T74/2179—Adjustable
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T83/00—Cutting
    • Y10T83/465—Cutting motion of tool has component in direction of moving work
    • Y10T83/4737—With tool speed regulator
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T83/00—Cutting
    • Y10T83/465—Cutting motion of tool has component in direction of moving work
    • Y10T83/4766—Orbital motion of cutting blade
    • Y10T83/4795—Rotary tool

Definitions

  • the invention relates to an adjustable throw crank having a crank pin which can be moved radially and mechanical means for adjusting the radial position of the crank pin.
  • Such mechanical means may comprise an internally screw-threaded bore in a crank arm, an externally screw-threaded spindle rotatably mounted in a non-adjustable part of the crank, and means for rotating the spindle to change the radial position of the crank arm.
  • Such adjustable throw cranks are used for example in rotating shears (also called flying shears) in order to change the peripheral speed of the cutting blade whilst keeping the same speed of revolution.
  • rotating shears also called flying shears
  • the centrifugal force acting on the crank is in the opposite direction to the cutting force at the moment of shearing.
  • the thrusting device consists of a lock-nut which bears against the internally screwthreaded bore.
  • This thrusting device has however a number of disadvantages.
  • the use of this thrusting device is very troublesome because the lock-nut must be loosened by hand every time the crank throw is altered and must be again tightened up after the alteration.
  • the lock-nut can only be screwed onto the end of the spindle which projects out of the internally screw-threaded bore, so that the crank pin is thrust in the same direction as that in which the centrifugal force operates.
  • the cutting force which occurs at the moment of shearing is considerably larger than this centrifugal force. If one wants to avoid the jump or play in the screw thread, the lock-nut must be so strongly tightened that the tightening force is larger than the cutting force. This causes great wear of the screw thread.
  • an adjustable throw crank having:
  • crank pin which can be moved radially
  • a pressure fluid (preferably hydraulic) operated thrusting device for taking up any play in the mechanical adjusting means by thrusting the crank pin towards the axis of rotation of the crank shaft, the thrusting device normally having at least one pressure fluid ram connecting the crank pin to a nonadjustable part of the crank.
  • the thrusting device may be actuated by centrifugal force created when the crank rotates; if the thrusting device has at least one pressure fluid thrusting ram connecting the crank pin to a non-adjustable part of the crank, for thrusting the crank pin, there may be a further ram connected to said thrusting ram(s), a radially movable centrifugal body and means mechanically connecting the centrifugal body to said further ram such that rotation of the crank causes the centrifugal body to pressurize the pressure fluid in said further ram and hence pressurize the pressure fluid in said thrusting ram(s); i.e., the further ram is so positioned on the crank and so cooperates with the centrifugal body that the piston of the further ram is thrust into the cylinder when the crank rotates. If there is a pressure fluid reservoir
  • This construction has the advantage that as the crank rotates, the centrifugal body presses the pressure fluid out of said further ram into said thrusting ram(s) and hence increases the thrusting pressure in the same way as the centrifugal force acts on the crank pin. In this manner, the pressure in the reservoir can be kept relatively small so that the mechanical adjusting means can be adjusted with ease when the crank is stationary.
  • the thrusting device may be pressurized by a fixed pressure I fluid pump or by a fixed pressure reservoir.
  • a rotating coupling in the pressure lead from the pump or reservoir to the thrusting device, at a certain position on the crank. This rotating coupling complicates the construction of the thrusting device and causes an additional leakage loss.
  • a pressure fluid reservoir may be fixed to the crank (preferably to a non-adjustable part of the crank) and connected to the thrusting device.
  • the thrusting device can be arranged such that friction between the bearing surfaces (e.g., between the bearing surfaces of the screw threads) is reduced and wear between these bearing surfaces is lessened.
  • the thrusting device can be arranged to. be self-contained and require no parts which do not rotate with the crank.
  • crank of the invention can be used in any suitable machine, particularly in machines where one experiences the problems that one has with flying shears.
  • This invention extends to a flying shear having the crank of the invention for driving the shear blade, the blade being mounted on the crank pm.
  • FIG. 1 is a view of the crank, looking in the direction of the crank pin;
  • FIG. 2 is a section through the crank along the line IIIl of FIG. 1;
  • FIG. 3 is a section through the crank along the line III-III of FIG. 2;
  • FIG. 4 is a schammatic diagram of the thrusting device with the pressure leads between the rams and the pressure reservorr.
  • crank shown in FIG. 1 has a crankshaft flange l which rotates about an axis M
  • a crank arm 2 having a radially movable crank pin 3, is fixed to the crankshaft flange 1.
  • the axis M of the crank pin 3 rotates about the axis M at a radius R. This radius can be altered according to the required speed of the crank pin 3.
  • crankshaft flange 1 is a part of a shaft 4 which is carried in a housing 5 by means of a bearing 6.
  • a toothed pinion 7 is fixed to the crankshaft 4, the toothed pinion being driven in a conventional manner by a motor (not shown).
  • An internally screw-threaded bush 9 is fixed to the crank arm 2, the bush 9 cooperating with a screw-threaded part 10 on a screw-threaded spindle 8 which is rotatably mounted in the crankshaft flange 1.
  • a collar 11 is provided for fixing the spindle 8 against movement radial to the crankshaft axis, the collar 11 hearing against a bearing bush 13 by way of a bevel gear 12; the spindle 8 is rotatably mounted in the bearing bush 13.
  • the bearing bush 13 sits in a lug l4 projecting from the crankshaft flange l.
  • the spindle 8 is also fixed against movement in a radial direction by means of a ring nut bearing against the lug 14 by way of an intermediate ring 16, an axial bearing 17 and a distance bush 18.
  • the spindle 8 is rotated by means of a shaft 20, a bevel gear 19 and the bevel gear 12; the shaft 20 is supported by a bearing 21 in a central bore in the crankshaft 4, and can be driven in the normal manner by a separate drive which is not shown.
  • the crank arm 2 is slidably guided in the radial direction-at three positions, by means of the sliding bushes 22 and 23.
  • the cooperating faces of the screw threads of the spindle 8 and the bush 9 are pressed against each other by means of a thrusting device which is described in detail below.
  • the cylinders 24 of two hydraulic rams are connected to the crankshaft flange l at each side of the crank arm 2 by means of stirrups or pipe clamps 26.
  • the cylinders 24 have piston rods 25 which have collars 27 bearing against lateral projections 28 on the crank arm 2, and the piston rods have their extended end portions guided in the sliding bushes 23.
  • the cylinder spaces in the cylinders 24 are connected with a pressure reservoir 29 by means of pressure leads 30 and 31, the pressure reservoir 29 being fixed to the crankshaft flange l.
  • the cylinder spaces of the rams 24, 25 are connected with the cylinder space of a further ram 33, 34 whose cylinder 33 is pivoted to the crankshaft flange 1 by means of a laterally projecting pivot pin 35.
  • the piston rod 34 of the cylinder 33 is connected by means of a pin 36 with a body 37 which can slide radially to the axis M the body 37 is pivoted about a pin 38 fixed to the crankshaft flange l in such a way that when the crank is rotating, the piston rod 34 is thrust into the cylinder 33 under the influence of centrifugal force acting on the body 37.
  • a further opening 40 is provided in the centrifugally actuated ram 33, 34, which opening is directly connected with the pressure reservoir 29 by way of a pressure lead 41.
  • This opening is only open for liquid flow when the piston rod 34 is in its extended position. The opening 40 is blocked as soon as the piston rod 34 is pushed a little into the cylinder 33 when the crankshaft begins to rotate.
  • the advantage of the opening 40 is that the-pressure fluid can flow out of the cylinder spaces of the rams 24, 25, through the ram 33, 34 and into the pressure reservoir 29 when the crank is still, if the crank radius R is to be increased. if this were not so, it would be necessary to insert an on/off valve in parallel to the check valve 32.
  • the centrifugal body 37 has also a nose 44 which, when the crank is still (as shown), lies against an abutment 42 on the crankshaft flange l. A further abutment 43 for the nose 44 limits the stroke of the piston rod I claim:
  • An adjustable throw crank having a non-adjustable part
  • crank pin which can be moved with respect to the non-adjustable part in a direction which is radial to the axis of rotation of the crank
  • a pressure fluid operated thrusting device for taking up any play in the mechanical adjusting means by thrusting the crank pin towards the axis of rotation of the crank.
  • a crank as claimed in claim 1 and including a pressure fluid reservoir fixed to the crank and connected to the thrusting device.
  • a crank as claimed in claim 1, wherein the thrusting device comprises means rotating with the crank and sensitive to centrifugal force to thrust the crank pin towards the axis of rotation of the crank.
  • a crank as claimed in claim 3, wherein the thrusting device has at least one pressure fluid thrusting ram connecting the crank pin to the non-adjustable part of the crank, for thrusting the crank pin towards the axis of rotation of the crank, a further ram connected to said thrusting ram, a radially movable centrifugal body, and means mechanically connecting the centrifugal body to said further ram whereby rotation of the crank causes the centrifugal body to increase the pressure of the pressure fluid in said further ram and hence in said thrusting ram.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Transmission Devices (AREA)
  • Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
  • Clamps And Clips (AREA)
US51744A 1969-06-28 1970-06-29 Crank with adjustable crank radius Expired - Lifetime US3672242A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19691933008 DE1933008A1 (de) 1969-06-28 1969-06-28 Spanneinrichtung

Publications (1)

Publication Number Publication Date
US3672242A true US3672242A (en) 1972-06-27

Family

ID=5738362

Family Applications (1)

Application Number Title Priority Date Filing Date
US51744A Expired - Lifetime US3672242A (en) 1969-06-28 1970-06-29 Crank with adjustable crank radius

Country Status (5)

Country Link
US (1) US3672242A (enrdf_load_stackoverflow)
JP (1) JPS4812501B1 (enrdf_load_stackoverflow)
DE (1) DE1933008A1 (enrdf_load_stackoverflow)
FR (1) FR2051415A5 (enrdf_load_stackoverflow)
GB (1) GB1302076A (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4056994A (en) * 1975-11-05 1977-11-08 Irma Ungerer geb. Dollinger Flying shear for the crosscutting of metal strips or bands
EP0474123A1 (en) * 1990-09-06 1992-03-11 Kimberly-Clark Corporation Extrusion coated nonwoven laminate, process of making and use of same

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51128201U (enrdf_load_stackoverflow) * 1975-04-15 1976-10-16
JPS5341703A (en) * 1976-09-29 1978-04-15 Hitachi Ltd Electric rotary machine of gap winding model

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4056994A (en) * 1975-11-05 1977-11-08 Irma Ungerer geb. Dollinger Flying shear for the crosscutting of metal strips or bands
EP0474123A1 (en) * 1990-09-06 1992-03-11 Kimberly-Clark Corporation Extrusion coated nonwoven laminate, process of making and use of same

Also Published As

Publication number Publication date
GB1302076A (enrdf_load_stackoverflow) 1973-01-04
JPS4812501B1 (enrdf_load_stackoverflow) 1973-04-20
FR2051415A5 (enrdf_load_stackoverflow) 1971-04-02
DE1933008A1 (de) 1971-01-07

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