US2940324A

US2940324A - Wobble drive

Info

Publication number: US2940324A
Application number: US629362A
Authority: US
Inventors: Belzner Paul
Original assignee: Schmid and Wezel GmbH and Co
Current assignee: Schmid and Wezel GmbH and Co
Priority date: 1955-12-21
Filing date: 1956-12-19
Publication date: 1960-06-14
Anticipated expiration: 1977-06-14

Description

IJune 14, 1960 Filed Dec. 19, 1956 WIM P. BELZNER 2,940,324

WOBBLE DRIVE 2 Sheets-Sheet 2 ATTORNEY WOBBLE DRIVE Paul Belzner, Muhlacker, Germany, assignor to Schmid & Wezel, Mauibronn, Wurttemberg, Germany Filed Dec. 19, 1956, Ser. No. 629,362

Claims priority, application Germany Dec. 21, 1955 2 Claims. (Cl. 74--60) The present invention relates to drives for converting rotary motion into reciprocating motion.

More particularly, the present invention relates to a wobble drive adapted to be used in hand tools, for example, for converting the rotary motion of a drive shaft into reciprocating motion of a driven shaft.

One of the objects of the present invention is to provide a wobble drive of the above type which is of a simple, compact construction and which does not include any eccentrically driven elements.

Another object of the present invention is to provide a drive of the above type which runs smoothly and easily and which will not bind.

A further object of the present invention is to provide a hand tool of the above type which can be comfortably handled and carried by the operator during operation of the hand tool.

With the above objects in View, the present invention mainly consists of a wobble drive for converting rotar-y motion into reciprocating linear motion, this drive including a support means and a drive shaft supported for rotation about its axis by the support means. A driven shaft is supported for reciprocation along its axis by the support means. A wobble spindle is connected by a suitable means to the drive shaft for tilting movement about a point in the axis ofthe drive shaft during rotation of the latter. A ball and socket joint is fixed to the driven shaft and includes a ball member formed with a bore, and a lever means is fixed to the wobble spindle and has a free end portion extending slidably into the bore of the ball member of the ball and socket joint, so that a tool or the like carried by the driven shaft will reciprocate therewith during rotation of the drive shaft.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing in which:

Fig. 1 is a sectional elevational view of a hand tool according to the present invention, the wobble drive being shown in Fig. 1 in neutral position where the driven shaft will not reciprocate during rotation of the drive shaft;

Fig. 2 is a sectional view of an adjusting means of the wobble drive, Fig. 2 being taken along line 2-2 of Fig. l in the direction of the arrow;

Fig. 3 is a schematic illustration of the operation of the wobble drive of the present invention; and

Figs. 4 and 5 are sectional elevational views, similar to Fig. 1, and showing the wobble drive in tiited position.

The structure shown in Fig. 1 includes a support means in the form of a housing 1, 2 which is relatively heavy. The portion 2 of the housing carries ball bearings which support a drive shaft 3 for rotation about its axis, and the bottom end of this drive shaft, as viewed in Fig. 1, is connited States Patent Of Patented June 14, 1960 ice nected in any suitable way to an unillustrated motor which rotates the drive shaft. The top end of the drive shaft 3, as viewed in Fig. 1, xedly carries a head member 4, which is of bell-shaped coniiguration and which is open at its top end, as viewed in Fig. 1, the head member 4 thus rotating with the drive shaft 3.

The drive of the invention includes a wobble spindle 7 which is coaxial with the drive shaft 3 in the position of the parts shown in Fig. l, and this spindle 7' is carried by a bearing means 5 provided with ball or roller bearings 6 which interconnect the spindle 7 with the bearing means 5 in a manner enabling the bearing means to rotate about the axis of the spindle 7. The bearing means 5 includes a pair of opposed pins 17 (Fig. 2) which respectively extend into opposed openings of the head member 4 so that the bearing means 5 is in this way connected to the head member 4 for turning movement about the common axis of the pins 17. It will be noted that this axis of the pins 17 is normal to the axis of drive shaft 3 and intersects the drive shaft axis at point a. Thus, the bearing means 5 can only turn with respect to the head member 4 about an axis which is at all times perpendicular to the drive shaft axis and the wobble spindle axis and which intersects th drive shaft axis at point a. Y Y

An adjusting means is provided to set the angle of the :bearing means 5 with respect to the head member 4, as

for instance shown in Figs. 4 and 5, and the details of this adjusting means are illustrated in Figs. l and 2. This adjusting means includes a nut in the form of an elongated internally threaded tube 12, and -this tube 12 xedly car'- ries a pair of coaxial, opposed, lateral pins which in turn carry annular bearing members 13. The bearing means 5 is formed with a bottom elongated cutout which extends to the right and left, as viewed in Fig. l and which re- Vceives the nut 12 in the manner indicated in Figs. 1 and 2,

and the side wall portions of the bearing means 5, which result from the bottom elongated cutout thereof, are respectively formed with aligned cutouts which are open at the bottom and which respectively receive the bearings 13. Arscrew 11 threadedly carries the nut 12 and extends through opposed openings of the head member 4, as shown in Fig. l, and this screw 11 is restrained against axial movement so that when the screw 11 is turned the nut 12 will move `axially therealong to set the bearing means 5 at a preselected angle which will determine the stroke of the driven shaft described below. The screw 11 may carry a nut at its right free end, as viewed in Fig. l, which may -be tightened to prevent turning of the screw 11 after the angular position ofthe bearing means 5 is adjusted. The housing portions 1 and 2 are removably connected t0 each other by suitable screws or the like, so that these housing portions may be separated to give access to the adjusting screw 11. When the housing portions 1 and 2 are separated from each other, the entire drive is carried by the housing portion 2, the tool 19 being disconnected from the driven shaft 9 and the latter simply slipping out of open- -ings of the housing portion 1 when the latter and the housing portion 2 are separated from each other and the hand tool is reassembled with the reverse of this procedure. If desired, the housing portions 1 and 2 may be permanently connected to each other, and access to the adjusting screw 11 may be provided through an opening of the housing portion 1 which can be covered by a plate removably connected to the housing portion 1. Instead of two sets of ball or roller bearing members 6, as shown in Fig. l, a single set may be provided.

The driven shaft 9 is slidablj,l supported in suitable openings of the housing portion i for reciprocating movement in a direction parallel to the axis of the drive shaft 3. The bottom free end portion of the driven shaft 9 which is located within the housing portion 1 xedly carries a socket member of a ball and socket joint which includes the ball member 8. This ball member 8v is formed with a bore extending along a diameter of the ball member. v

1 Y1A levermeans 7 interconnects the wobble spindle 7' Ywith the VballV member 8, and the lever means 7 has a configuration which locates the center b of ball member 8 in a straight line which is at all times perpendicular totheaxis' of the wobble spindle' and which passes through the point a. This lever..meansV 7V yincludes Va i substantially L-shaped member one leg of which is xed to the wobble spindle 7' and the Vother leg ofwhich is vfixed to a pin which extends through a rcutout f the rsocket ofthe ball and socket joint slidably into the bore of the ballV member 8. The cutout of the socket member is large enough to prevent rubbing of the pin of lever means `7 which extends into the bore of ball member 8 against the socket member during operation of theV drive. During reciprocation ofthe driven shaft 9, this pin slides zback and forth into the bore of the ball'member 8. In this way all'binding is veliminated with the structure of the invention. Itis apparent that when the parts have the-position'shown in Eig. 1, the shaft 9 will not recip- Y Vrocate during rotation of'the drive shaft 3, whilethe extent ofreciprocation of the shaft 9 will` depend upon ,the angular position of bearing means Swith respectto V thecornnion axis of, pins 17, this angular position being set by turning the screw 11.

Any suitable tool such as a scraper blade 10 is remov-V Y ably iixed to the driven shaft 9 for Vrec-iprocation there- Y amasarv v .withrespect to theA axisof drive shaft' and which serves as` a hand grip enabling the operator tosecurely hold y,and easilyrguide the tool. In order to prevent slipping of the hand'of the'operator with respect to the Yhousing 1, an elongated flexible band 14 of leather or the like is fixed to the housing 1 and formsa loop passing over thebulging portion 15 so that the hand of the operator when it engages the bulging portion y15 will be securely located between the'housing portion 1 and the band 14. Any suitable buckle or the like ymay be provided on the `band 14 to form a means for adjusting the length thereof. The drive shaft 3 may be driven by any suitable electric motor, such as a universal motor, a rotating eld motor, a high frequency motor, or an air driven motor may be used. Also, a suitable gear transmission may be located between the motor and the shafty 3 for rotating figuration.

4 a useful application in other types of drives differing from the types describedtabove.

While the invent-ion has been illustrated ,and described as embodied in wobble drives, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt itfor various apphcations without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specicaspects of this invention and, therefore, such adaptations should and are intendedrto be comprehended within the meaning and range of equivalence of the following claims.

What :is claimed as new and desired to be secured by Letters Patent is: Y t

.1. A wobble drive for converting rotary motion into reciprocating linear motion comprising in combination, support means; a drive shaft supported for rotation aboutits axis by said support means; a cup-shaped head member iixed to said drive shaft for rotation therewith; a wobble spindle; bearing means supporting said wobble spindle and being freely turnable about the axis ofsaid wobblespindle, said bearing means mounted within said Vcup-shaped headY memberY and connected thereto for turning movement about an perpendicular to the axis of said drive shaft and the axis of said wobble spindle; adjusting means operatively connected to said bearing means Yfor setting the angular position thereof with respect to said axis perpendicular to said drive shaft and wobble spindlejaxes, said adjusting means including a nut to which said bearing means is connected for Yturning movement about another axis perpendicular to said drive shaft and wobble spindle axes and a screw .carried for turning movement about its axis by said head member and. extending threadedly through saidV nut, said screw being restrained by said head member against .'axial movementV so that when said screw is turned said nut Vshifts 'axially to tilt said bearing means with respect to said head member; a driven shaft'supported for reciprocation along its ax-is by said support means; tool means fixed to said driven shaft for reciprocation'therewith; a ball and` socket joint fixed to said driven shaft vand includingra ball member formed withra bore; and

lever meansrxed to said wobble spindle and having a `free end portion extending `slidably into said bore of said ball member. i

2. A wobble drive as recited in claim 1 and wherein said bearing means has a substantially spherical'con- References Cited in the tile of this patent UNITED STATES PATENTS 1,222,391 Grant- Apr. l0, 1,917 1,679,884 Thomas Aug. 7, 1928 1,901,981 Ousback Mar.,2l, 1933 2,246,689 Kost June 24, 1941 2,247,527 lStinnes f July 1, 1941 2,824,455V