US3842925A - Device for raising weights in precision balances - Google Patents

Device for raising weights in precision balances Download PDF

Info

Publication number
US3842925A
US3842925A US00294736A US29473672A US3842925A US 3842925 A US3842925 A US 3842925A US 00294736 A US00294736 A US 00294736A US 29473672 A US29473672 A US 29473672A US 3842925 A US3842925 A US 3842925A
Authority
US
United States
Prior art keywords
weights
pins
raising
disc members
balance
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
US00294736A
Other languages
English (en)
Inventor
C Crespi
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Application granted granted Critical
Publication of US3842925A publication Critical patent/US3842925A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01G—WEIGHING
    • G01G1/00—Weighing apparatus involving the use of a counterweight or other counterbalancing mass
    • G01G1/18—Balances involving the use of a pivoted beam, i.e. beam balances
    • G01G1/26—Balances involving the use of a pivoted beam, i.e. beam balances with associated counterweight or set of counterweights
    • G01G1/28—Balances involving the use of a pivoted beam, i.e. beam balances with associated counterweight or set of counterweights involving means for automatically lifting counterweights corresponding to the load

Definitions

  • ABSTRACT Device for raising weights in precision balances.
  • analytical balances in which a number of weights from the smallest to the largest are disposed substantially in a single plane and are made associated with at least two pusher raising elements mobile in a direction substantially orthogonal to the plane of the weights, the pusher raising elements being raised by programmed operating means including rotatable annular disc members and cam means provided thereon. The disc members are rotated by acting on the weighing control members of the balance.
  • the present invention relates to a device for raising and lowering weights in precision balances.
  • Precision balances for example analytical balances, comprise a certain number of weights suspended at one end of the balance arm and a counterweight disposed at the opposite end of the arm, in such a manner as to exactly balance the balance.
  • a number of weights are raised equivalent to the weight placed on the plate so as to again balance the balance.
  • This operation is carried commonly out by hooks controlled by levers, which take each weight and raise it so that it no longer bears on the arm of the balance.
  • a set of knobs is provided for controlling the levers, and their rotation causes movement of the levers by the action of corresponding means such as cams etc.
  • the weights are hence disposed along a number of axes or horizontal planes one below the other, so as to limit the number of weights in each plane and make possible the raising operations for all weights from the mechanical point of view.
  • An object of the present invention is to overcome the aforementioned disadvantages of known precision balances by providing a device for raising the weights which firstly introduces no possibility of error in weighing, even in the case of extremely small weighings, and
  • Another object of the invention is to provide a device easily installed on precision balances and of durable operation.
  • a device for raising weights in precision balances in which all the weights from the smallest to the largest are disposed substantially in a single plane and are each associated with at least two pusher raising elements mobile in a direction substantially orthogonal to the plane of the weights, the pusher elements being raised by programmed operating means associated respectively with the weighing control members of the balance.
  • FIG. 1 is a diagrammatic lateral view of a precision balance to which the device of the invention is applied;
  • FIG. 2 is a partially exploded view of the device of the invention
  • FIG. 3 is a view from above of the balance of FIG. 1 without the cover;
  • FIG. 4 is a plan view of the means for the programmed raising of the weights
  • FIG. 5 is a section on the line VV of FIG. 4'
  • FIG. 6 is a part of the support for the weights
  • FIG. 7 shows a detail on an enlarged scale of the pusher elements for raising the weights
  • FIG. 8 is a lateral view of the clamping device for the means for the programmed raising of the weights.
  • FIG. 9 shows a detail of the balance arm.
  • the device 1 according to the invention is imagined applied to an analytical balance which in known manner comprises at its lower front part the compartment with the weighing plate 2 and in its upper part the actual members of the balance.
  • the balance beam 3 is supported through the central fulcrum 4 by the column 5 and is provided with the counterweight 6 and air damper 7 at one end and the.
  • the weighing operation is carried out by manually operable control means such as knobs 12, 12a and 13, 130 by way of appropriate transmission devices 14 which will be described in greater detail hereinafter.
  • all the annular weights from the smallest to the largest, are disposed concentrically in the same horizontal plane, and supported in this plane by the arms 15 disposed at one to the other to constitute the support member for the weights.
  • arms 15 comprise notches 16 of a number corresponding to the number of the weights and ofa suitable shape and size for seating the weight according to its size and they converge at the central body 18, to which the rods 9 are fixed,
  • the weights are disposed in increasing order from the centre and in the example under consideration they are the following: two weights of 100 mg, one of 200 mg, one of 500 mg, two weights of l g, one of 2 g, one of g, two weights of g, one of 20 g, one of 50 g, and one weight of 100 g. in this manner there is a total of 13 weights whose sum total is I99.900 g. It is to be understood however that their number and value could be different.
  • the device 1 Immediately below the plane of the weights but free from it, the device 1 comprises the pusher elements and the operating means for the programmed raising of the weights, indicated overall by the reference numeral 20. More precisely the device 1 comprises a base 21 of cylindrical form, to whose lateral surface 22 are fixed at 90 one to the other the supports 23, provided at their free end with a notch 24 in which is clasped the corresponding end of the transverse stop bars 25, whose form is visible inFlG. 5 and against which the raised weights engage.
  • the crosspieces 26 and 27 are fixed to the supports 23 below the bars and define guiding means in which pins 28 and 29 are slidable in a direction orthogonal to the plane of the weights 8.
  • the pins 28 and 29 constitute the pusher elements for raising the weights and are distributed in such a manner that each pair of diametrically opposing pins supports a single annular weight, the pairs being alternated between one crosspiece and the other as passage is made from one weight to the next.
  • the means for the programmed operation of the pins comprise rotatable annular disc members or programming plates 30, 31, 32 and 33, which each comprise on their upper face as series of profiles or cams 34 disposed according to a precise programme, and on their lower face operating means including a respective annular too thing 35 which meshes with three gearwheels 36, disposed at 120 one to the other.
  • One of the gearwheels 36 of each plate is fixed rigidly to a shaft 37 which emerges from the lateral surface 22 of the base 21 and comprises a bevel gear 38, operatively connected to the knobs 12, 12a and 13, 13a.
  • the other gearwheels 36 of each plate are fixed to respective shafts housed idly in the lateral surface 22 and in the central part 40 of the base 21 and serve exclusively as a support for the programming plates, which thus also lie in a single plane as the weights 8.
  • the disposition of the various gearwheels below the programming plates, and of all other toothed wheels for the operation of the programming plates, is shown in FIG. 3 in which the details above the plates and the weights have been omitted.
  • the entire device 1 is removably mounted on the shelf 41 of the balance.
  • the internal programming plates 31, 32 33 have ten cam profiles or portions which are repeated identically over the angular development of each of them.
  • the most external plate 30 has instead a different profile and comprises only four cam portions. For this reason only the form of the profiles ofthe plates 31 and 30 will be described hereinafter.
  • each of the internal programming plates 31, 32 and 33 are associated four weights, multiples of 10 of the two weights of I00 mg, of that of 200 mg and of that of 500 mg. With this values of weights it is possible, as is known, to define an entire weight decade. With the external plate 30 is associated a single weight of 100 g.
  • One turn of the programming plates 31, 32 and 33 corresponds to an entire weighing are from 1 to 9 100-900, [0-90) plus the position 0, so as to obtain all the weight values which are multiples of 100 mg. in order to obtain this each of the plates 31, 32 and 33 has the profiles 34 disposed on five concentric circumferences, the profiles being diametrically symmetrical in pairs.
  • the plate 31 has thus two sections 310 acting on the pins situated below the first weight of IO g, two sections 311) and two sections 310 acting on the pins situated below the second weight of 10 g, two sections 31d acting on the pins corresponding to the weight of 20 g and finally a cam portion 31c and a cam portion 31f, both for raising the weight of 50 g, but situated on different circumferences.
  • This latter weight must in fact be held lowered for one half of a turn and raised for the other half, so that a single cam acting on diametrically opposed pins could not cause the pins to be either both raised or both lowered.
  • one of the relative pins has its upper end eccentric with respect to its lower end (FIG. 7).
  • the external programming plate 30 comprises two sections 30b and 30c relative to the weight of 100 g, disposed angularly distanced as the sections 311) and 310 of the plate 31.
  • the drawings show also the corresponding sections 32a, 32b, 32c, 32d, 32e and 32f and the sections 33a, 33b, 33c, 33d, 33e and 33fof the profiles of the plates 32 and 33.
  • the length of the individual sections of the profiles is such that for each angle of rotation of 36 of the plate, an increase in weight of one relative unit is obtained, in the succession described hereinafter.
  • the last weight of 100 g requires only two positions, one raised and one lowered, and hence the profiles of the external plate 30 comprise in substance two sections 30b and 30c separated by 72, so as to give a position of 0 between two raising positions.
  • the weights and the positions of the plates and pins shown in the drawings are those relative to a hypothetical weighing of 170.600 g.
  • the raised weights are made to lightly touch the transverse bars 25 with a slight pres sure.
  • the pins are advantageously composed (FIG. 7) of a lower shank 42 rigid with a body 43 of substantially cup form guided in a corresponding seat 44 in the cross bars 26 and 27 respectively, and an upper shank 45 mobile in the body 43 and supported by a spring 46 inserted in the body 43.
  • One of the two pins for raising weights which are multiples of 500 mg is eccentric, as stated, and it comprise two shanks 42 and 45 olT-centre in the body 43a.
  • the presence of the spring enables the efiect of the impact of the weights against the bars 25, which could damage the weights, to be dampened, and simultaneously makes the operation of the programming plates more smooth.
  • the weights supported by the arms are all engaged with the bars, even if the pins are all lowered.
  • Rotation of the programming plates by the bevel gears 36 takes place by way of the knobs 12, 12a and 13, 130, each of which (FIG. 3) is associated with one ofthe programming plates.
  • the knobs l2 and 13 act by way of the gearwheels 47 and 48 rigid with the shafts on which the knobs are fixed, and the gearwheels indicated generally by the reference numerals 49 and 50 on the bevel gears 36 of the plate 33 and 30, respectively.
  • the knobs 12a and 13a act by way of the gearwheels 51 and 52, rotably rigid with these knobs, on the gearwheel assemblies indicated generally by the reference numeral 53 and 54, respectively, with which the remaining plates 31 and 32 are associated.
  • Advantageously snap action devices consisting of notched wheels 55 and springs 56 engaged with these notches for the rotation of the knobs through a predetermined angle and their exact arrest in each weighing position.
  • the transmission 47-54 is so calculated in the ratios of the different gearwheels that with one turn of each programming plate there corresponds one turn of the corresponding knob, so that the snap action devices act on each 36 of rotation both of the knobs and of the programming plates, so defining without any possibility oferror the exact position in which each weight is perfectly raised or lowered and not in an intermediate position.
  • the knobs are associated circular scales numbered from 0 to 9, by which it is possible to directly read the weighing value on a suitable panel at the front of the balance.
  • the scales are one within the other on each side, so as to give the values in the exact order of reading from left to right.
  • Each weighing position can be locked by the locking device shown in FIG. 8.
  • This is arranged on the shelf4l of the balance in a position corresponding with a cavity 57 in the base 21 and comprises four pins 58, one under each plate, designed to enter relative dead holes 58a provided under the plates at a distance one from the other of 36, starting from a predetermined position.
  • the pins 58 are fixed to a plate support 59 which is mobile above the bracket 60, fixed to the shelf 41 of the balance, and comprises guide pins 61 passing through suitable holes 62 in the bracket 60.
  • a lever 63 is provided pivoted at 64 on the shelf 41 of the balance, and acts on the wheel 65 carried by the rod 66 screwed into the plate support 59 and guided in the sleeve 67 fixed to the bracket 60.
  • the springs 68 arranged between the bracket 60 and enlarged end of the pins 61, remove the pins 58 from their engagement in the dead holes 58a of the programming plates.
  • Control of the locking device is by the rod 69 operating connected to the lever 70 disposed in the lower front part of the balance.
  • an optical system may be provided for reading the last figures of the weighing, and comprising (FIG. 3) a graduated scale disposed on the arm 3 in axis with the luminous ray produced by the lamp 73, and a fixed mirror 76 for reflecting the luminous ray coming from lamp 73 through lenses 74 and 75 on to a vernier scale provided on a suitable panel in the upper front part of v the balance.
  • the device may be applied to types of precision balances different to that illustrated and wherever greater weighing precision and lower constructional cost is required, for example in the field of technical balances, and furthermore the various control means and means for raising the weights may be modified according to requirements.
  • a control system is provided having all pins rigid with one plate, which is raised according to a programme by cams suitably set to raise the various weights in succession.
  • a fixed programming plate in which a number of holes are disposed in accordance with a set pro gramme, so that the underlying plate carrying the pins brings a certain number of pins under the relative holes in the fixed programming plate for each section of rotation, and when raised pushes the pins into these holes, so raising the relative weights, while the pins not aligned with the holes remain inactive.
  • a device for raising and lowering the weights in precision balances of the type having a balance beam, a support member suspended at one end of said balance beam, a plurality of annular weights supported by said support member concentrically to each other in a substantially horiziontal plane, and manually operable control means for controlling the raising and lowering of said weights, the device comprising a base for removable connection to said balance below said support member, guiding means provided over said base and extending below said weights substantially radially thereto, a plurality of pusher elements including pins slidable within said guiding means substantially perpen dicularly to the plane of said weights for raising and lowering said weights, means for operating said pins including rotatable annular disc members arranged concentrically to each other in the same plane below said guiding means and having an upper face provided with cam means for engaging said pins and a lower face provided with operating means for independent rotation of said disc members, said operating means being operatively connected to said manually operable control means of the balance, whereby operation of said
  • said operating means for independent rotation of said disc mem bers comprise an annular toothing provided on the lower face of each of said disc members concentrically thereto, each of said toothings being operatively connected to said manually operable control means of the balance by means of gearing.
  • said guiding means comprise two crosspieces arranged at right angles to each other in a substantially horizontal plane above said disc members, said crosspieces each having pairs of through bores for receiving respective pairs of said pins, each pair of said pins engaging one of said weights at diametrically opposite points, the pairs of pins relative to adjacent weights being disposed alternatively in the one and the other of said crosspieces.
  • At least one of said disc members has an external cam comprising two cam portions arranged opposite to each other along annular concentric pathes of slightly different radii and each extending for a half of its circumference, with each of said cam portions being associated one pin comprising an upper and a lower shank, the shanks of one of said pins being coaxial to each other and the shanks of the other of said pins being off-centered, whereby the said upper shank engages the corresponding one of said annular weights and the said lower shank engages the corresponding one of said two cam portions.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Motorcycle And Bicycle Frame (AREA)
  • Testing Of Balance (AREA)
  • Measurement Of Force In General (AREA)
  • Toys (AREA)
  • Sampling And Sample Adjustment (AREA)
US00294736A 1971-10-05 1972-10-03 Device for raising weights in precision balances Expired - Lifetime US3842925A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT53269/71A IT939506B (it) 1971-10-05 1971-10-05 Bilancia analitica a caricamento rotatorio

Publications (1)

Publication Number Publication Date
US3842925A true US3842925A (en) 1974-10-22

Family

ID=11281356

Family Applications (1)

Application Number Title Priority Date Filing Date
US00294736A Expired - Lifetime US3842925A (en) 1971-10-05 1972-10-03 Device for raising weights in precision balances

Country Status (10)

Country Link
US (1) US3842925A (ja)
JP (1) JPS5013072A (ja)
CA (1) CA973573A (ja)
CH (1) CH560891A5 (ja)
DD (1) DD104138A5 (ja)
DE (1) DE2248687A1 (ja)
FR (1) FR2156011B3 (ja)
GB (1) GB1409800A (ja)
IT (1) IT939506B (ja)
NL (1) NL7213452A (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4411328A (en) * 1982-03-24 1983-10-25 Pitney Bowes Inc. Low range automatic weighing device

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4870464A (ja) * 1971-12-23 1973-09-25
JPS596436B2 (ja) * 1976-04-30 1984-02-10 株式会社東芝 繰り返し信号の状態判定回路
JPS5936629U (ja) * 1982-08-31 1984-03-07 日本電気ホームエレクトロニクス株式会社 比較回路

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4411328A (en) * 1982-03-24 1983-10-25 Pitney Bowes Inc. Low range automatic weighing device

Also Published As

Publication number Publication date
JPS5013072A (ja) 1975-02-10
GB1409800A (en) 1975-10-15
DE2248687A1 (de) 1973-04-19
CH560891A5 (ja) 1975-04-15
FR2156011A1 (ja) 1973-05-25
NL7213452A (ja) 1973-04-09
CA973573A (en) 1975-08-26
DD104138A5 (ja) 1974-02-20
IT939506B (it) 1973-02-10
FR2156011B3 (ja) 1976-02-20

Similar Documents

Publication Publication Date Title
US3842925A (en) Device for raising weights in precision balances
US2764400A (en) Balance
JP3968002B2 (ja) 電子秤用分銅セット
US3891040A (en) Inclination spring balance
EP0093183B1 (de) Waage
US2716546A (en) Weighing mechanisms
US1624588A (en) Weighing scale
US2950100A (en) Balance
US2558162A (en) Pendulum weighing scale with tare setting means
US1427760A (en) Scale
DE618399C (de) Anzeige- oder Druckvorrichtung fuer Neigungswaagen oder aehnliche Messinstrumente
US3111180A (en) Beam type weighing scale
US2458704A (en) Spring testing scales
US2193660A (en) Counting scale
US3720275A (en) Device for reading pendulum-cam scales beam positions and for placing and removing weights
US2382752A (en) Recording scale
US1706510A (en) Weighing scale
US1161009A (en) Combined weighing and counting machine.
US2610844A (en) Scale
US1838019A (en) Even balance scale
US3659664A (en) Weighing apparatus
US1408264A (en) Frederick a
DE2250008A1 (de) Verfahren und vorrichtung zum ausgleich der erdbeschleunigung an federwaagen
US3700056A (en) Top loading precision balance having annular weights
SU1587325A1 (ru) Устройство дл градуировки тензорезисторов