US1805841A - Planetary gear operated lifting jack - Google Patents

Description

May 19, 1931. l.. D. NlLsoN 1,805,841

PLANETARY GEAR OPERATED LIFTING JACK Filed Dec. 5, 1927 4 Sheets-Sheet 2 64 m fg 72 75 7/ 72 4W 7% 4f 41,35 f; l

May 19 1931. D. NlLsoN PLANETARY GEAR OPERATED LIFTING JACK Filed Dec. 5, 1927 4 Sheets-Sheet 3 zz/mhz Zlf" zzeyf Zea/zam Yzlya/ /Qm/ 90mm@ f May 19, 1931. L. D. NlLsQN 1,805,341

PLANETARY GEAR OPERATED LIFTING JACK Filed Dec. 5, 1927 4 Sheets-Sheet 4 4m 4 zz/@afar Z lfd/zam Z. IBI/mz@ yw @wwf/5%.

Patented May 19, 1931 UNITED STATES PATENT OFFICE LEQNARD D. NELSON, OF WAYZATA, MINNESOTA, ASSIGNOR T MARQUETTE MANU- FACTURING COMPANY, 0F ST. PAUL, MINNESOTA PLANETARY GEAR OPERATED LIFTING JACK Application iled December 5, 1927.

The object of my invention is to provide a Small three Wheeled lifting ack of simple,

durable and comparatively inexpensive construction.

Still a further object is to provide in a jack of this character a triangular shaped lifting arm pivoted at a comparatively high point on the frame of the jack and having a lifting head adapted to be normally positioned quite close to the ground and yet when raised it will raise the axle of thecar to a considerable height. Still a further objectis to provide on the triangular shaped lifting arm a series of gears and to provide 1'5 on the frame of the jack a curved rack bar with which one of these gears cooperates whereby rotation of the gears will cause the gear meshing with the rack bar to travel along the rack bar and thereby move the lifting arm relative to the frame of the jack for the purpose of raising a load.

Still a further object is to provide a ratchet wheel connected with one of the train of gears `and means for rotating the as ratchet Wheel whereby the train of gears will be rotated for raising the lifting head.

Still a further object is to provide a pair of paw-ls, one pivoted to the lifting arm and another pivoted to a link which in tur-n is pivoted on a shaft on Which the ratchet wheel is positioned whereby oscillating movement of the link will cause the pawl thereon to serve as a lifting pawl and the other pawl will serve as a holding pawl.

Still another object is to provide an operating means comprising a handle oscillatably mounted on the frame of the jack and operatively connected to the link for the purpose of actuating the lifting pawl.

4o Still another object is to provide a novel means for reversing the rotation of the ratchet wheel comprising a cam shaped member pivotally mounted on the shaft of the ratchet wheel and having cam surfaces to engage portions of the lifting and holding pawls to render them successively inoperative when it is desired to lower the load.

Still another object is to provide a means for counteractng the varying amount of Serial No. 237,739.

power required to lift a load due to the-constantly changing angle of the lifting arm as it is being raised whereby the power imparted to the jack through the medium of the operating handle may be comparatively constant throughout the movement of the lifting arm.

Although the invention is susceptible of a variety of embodiments, it is unnecessary to fully describe and illustrate more than one 50 in order to give a full understanding of the invention both from its structural and functional st-andpoints. Accordingly, I have i1- lustrated a preferred and desirable embodiment of the invention in the accompanying drawings forming a part of this specification and throughout the views of which like reference characters refer to the same parts.

With 'these and other objects in view, my invention consists in the construction, ar- 7o rangement and combination of the? various parts of my planetary gear operated lifting jack whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Figure 1 is a plan view of my improved type of jack.

Figure 2 is a plan view of the operating handle therefor and is substantially a continuation of the left hand end of Figure 1.

Figure 3 is a side elevation of my jack showing the lifting head thereon in raised position.

Figure 4 is a longitudinal sectional view 85 take-n on the line 4-4 of Figure 1 illustrating the internal mechanism of the jack.

Figure 5 is a longitudinal sectional view taken on the line 5 5 of Figure 1 illustrating the reversing mechanism and its operative connection to the operating handle of the jack.

Figure 6 is a longitudinal sectional view taken ou the line 6-6 of Figure 1 illustrating the lifting pawl supporting link and lthe springs connected thereto for holding the lifting and holding pavvls in contact with the ratchet Wheel.

Figure 7 is a longitudinal sectional view taken on the line 7&7 of Figure i illustratwe ing the step down gearing connection between the ratchet wheel shaft and the curved rack secured to the frame of the jack.

Figure 8 is a transverse sectional view taken on the line 8 8 of Figure 5.

Figure 9 is a transverse sectional view taken on the line 9-9 of Figure 5.

Figure 10 is a side view of the operating handle shown in Figure 2.

Figures 11, 12, 13, and 14 are sectional views similar to a portion of Figure 4 and showing the various parts of the jack in different positions when the reversing mechanism is in operation for coacting with the holding and lifting pawls whereby the ratchet wheel may be given reverse rotation for lowering the lifting head; and

Figure 15 is a similar view showing the reversing mechanism operating to hold both the lifting and holding pawls out of engagement with the ratchet wheel so that the lifting head will drop to lowered position.

On the accompanying drawings I have used the reference numeral 10 to indicate a frame member for supporting the various parts of my jack. There are two of the frame members 10 as clearly shown in Figure l of the drawings and they are spaced from each other. The rear ends of the frame members 10 are connected by a. yoke 12 and the front ends of the frame members are provided with horizontal hubs 14.

Formed on the yoke 12 is a vertical hub 16 adapted to receive a spindle 18 of a swivel caster wheel 20. The caster wheel 20 is rotatably mounted on a shaft 22 which is connected by a yoke 24 to the spindle 18. A pin 26 may be provided to prevent the spindle 18 from dropping out of the hub 16 in case the forward end of the jack is raised. A ball type thrust bearing 28 may be interposed between the yoke 24 and the yoke 12 for the purpose of allowing the wheel 2O to freely swivel relative to the frame of the jack. It will be noted that the central part of the yoke 12 is arched away from the swivel caster 2O thereby allowing plenty of room for it to turn in the hub 16.

Extending through the hubs 14 is a shaft 80. On each end of the shaft 80 mounted a supporting wheel 32 and the wheels 82 may be retained in position by pins 34 extending through the shaft 86. lf desired the wheels 32 may be provided with rollei` bearings 36 as shown in section in Figure 1 of the drawings and the caster wheel 2O may also be provided with roller bearings if desired.

rlhree bolts 38 extend through the frame members 10 from one side thereof to the other and are provided with nuts 40 on their ends. Spacer sleeves 42 are positioned on the bolts 88 between the frame members 10 whereby tightening of the nutsy 4() will serve to hold the frame members 10 in Lsoas41 proper assembled position relative to each other.

Mounted on the lower bolts 38 adjacent the side members l() are curved rack bars 44. The rack bars 44 have perforated ears 46 through which the two lower bolts 38 extend and the spacing sleeves 42 on these bolts eX- tend between the ears 46 of the two rack bars 44. In this manner the rack bars 44 are securely positioned against the side members l0.

Pivoted on shouldered bolts 48 is a pair of triangular shaped lifting arms 50. The pivot bolts 48 extend through one corner of these triangles. A load engaging and load lifting head 52 is mounted in a fitting 54 which in turn is pivotally mounted on another corner of the lifting arms by means of pivot pins 56. The third corner of each triangular lifting arm is provided with a widened portion 58 having downwardly eX- tending ears 60. The ears 60 are perforated and have positioned in them stub shafts 62. Mounted on the stub shafts 62 are pinions 64 and gears 66 formed integral with each other. The pinions 64 are adapted to mesh with the teeth of the curved rack bars 44 whereby rotation of these pinions will cause them to travel along the rack bars and thereby impart swinging movement to the triangular lifting arms.

The load engaging head 52 is provided with a shank 68 adapted to extend into a bore formed in the fitting 54. In this manner the load engaging head 52 is revolubly mounted with relation to the fitting 54.

To maintain the upper surface of the load engaging head 52 in a substantially horizontal position throughout the lifting movement of the lifting arms 5() I provide links 72 which in conjunction with the lifting arms serve as parallelogram arrangements to accomplish this purpose. The rear ends of the links 72 are pivotally mounted on shouldered bolts 74 secured to the frame members 10. The forward ends of the links 72 are pivoted on a pin 76 positioned in downwardly extending arms 78 on the fitting 54.

From the foregoing description it will be obvious that in order to raise the load lifting head 52 it is necessary to rotate the pinions 64 in one direction. lVhen it is desired to lower the lifting head the pinions 64 must then be rotated in an opposite direction. The mechanism for rotating the pin ions 64 in the desired direction will now be described.

The triangular shaped lifting arms 50 are provided with hubs 80 in which is journaled a ratchet wheel shaft 82. Keyed to the central portion of the ratchet wheel shaft 82 is a ratchet wheel 84. Teeth 86 are eut into the shaft 82 between the ratchet wheel 84 and the hubs 8() of the lifting armi.n 56. The

teeth 86 form pinion/s and .these pinions are in mesh with the gears 66fon the `stub shafts 62. From the construction yof fthe parts just described it will be obvious that rotation of the ratchet Wheel 84 in either-direction will cause rotation of the pinion 64 in a corresponding direction.

F or rotating the ratchet wheel 84 in one direction I provide a pair of links 88 and 90 which are rotatably mounted on 'the shaft 82 between the pinion-s 86 and the ratchet Wheel 84. The links 88 and 90 are adapted to pivotally support a lifting pawl 92 on a pivot lpin 94 extending through the upper ends of the links 88 and 90. The liftinv` pawl 92 is adapted to engage the teeth oi the ratchet wheel 84 and is held in engagement therewith by a lifting pawl spring 96. The spring 96 has one end secured as at 98 to the link '90 and its other end is secured to a pin 100 extending through the lifting pawl 92.

A pivot pin 102 -is supported in ears 104 formed on the yoke 12 adjacent the rear end of the jack. Oscillatably mounted Aon the pin 102 isa pair of operating handle bars 106 best shown in Figures 1 and 2 of the drawings. vThe bars 106 converge at their rear ends and are connected to a bar 108 which is provided with 'au enlarged operating handle 110. A pin 112 extends from one of the bars 106 to the other one and is substantially spaced above the pin 102. A link connection comprising bars 114 extends from the pin 112 `to the lifting pawl pin 94.

The lifting arms are connected by a web 116 whereby they form a rigid construction. Bearings 118 arc formed on the web 116 and support a holding pawl pin 120. A holding pawl 122 is pivotally mounted on 'the pin 120 in position Ito engage the teeth of the ratchet wheel 84. To cause such engagement a hoild-ing pawl spring 124 is provided. One end of the spring 124 is secured as at 126 to the web 116 and its other end is secured to a pin 128 extending through 'the holding pawl 122.

F rom the foregoing description it will be obvious that up and down oscillating Amovement imparted to the handle 110 will cause reciprocating movement of the bars 114 whereby the lifting pawl 92 will engage one of the teeth of the ratchet wheel 84 and retate it and the holding pawl 122 will hold it in its new position while the lifting pawl 92 is returned to engage the next tooth of the ratchet wheel. In this manner a step by step movement is imparted to the ratchet Wheel 84 which movement in turn is transmitted through the pinions 86, gears 66, pinions 64 coacting with the rack bars 44 so that a step by step raising movement .is imparted to the lifting head 52.

In Fi ure 4 of the drawings the operating han le 110 has been lowered as indicated by the arrow 130 whereby rotation of the ratchet Wheel 84 in the direction lof `the arrow 132 has been accomplished. Rotation of the ratchet wheel in this direction has been carried far enough to allow the holding pawl 122 vto drop into a notch of the ratchet wheel 84.

YWhen it is desired to reverse the rotation of the ratchet wheel 84 for the purpose of lowering the lifting head 52, the lifting pawl and the holding pawl must be manipulated to be successively moved to inoperative position with relation to the ratchet wheel 84. To accomplish this result I provide a cam type reversing member 134. The reversing member 134 is rotatably mounted on a hub 136 formed on the ratchet wheel 84. The member 134 is positioned between the ratchet wheel 84 and the link 88 as clearly illustrated in Figure 8 of the drawings. It will be noted that the upper end of the link 90 is provided with a hub which hub is missing on the link 88 to allow room for the member 134. The ymember 134 is provided with a lifting :pawl cam surface 138 and a holding pawl cam surface 140. The pins 100 and 128-of the lifting and holding pawls extend through the lifting and holding pawls and are provided with rollers 142 and 144 adapted to be engaged by the cam surfaces 138 and 140 respectively. A portion of the member 134 is cut away as at 146 to allow the holding Apawl 122 to function without interference with its roller 144 by the reversing member 134.

A pin 148 extends from the side of the member 134 and a chain 150 is connected to this pin. The chain 150 extends over a grooved head 1.52 formed on one of the lifting arm pivot bolts 48 and then toward the rear of the jack. One end of a spring 154 is connected to the free end of the chain 150. One end of a chain 156 is connected to the free end of the spring 154. The chain 156 extends over the upper spacing sleeve 42 and then .under the operating handle pivot pin 102. The chain 156 is in alignment with one of the ears 104 and this ear may be provided with an opening 158 to accommodate the chain.

The free end of the chain 156 is fastened to one end of a rod 160. The free end of the rod 160 is pivotally mounted on a stud 162 extending from a reversing lever 164. The reversing lever 164 is pivoted as at 166 to one side of the ope-rating handle bars 106 and 108 where they are connected together.

Normally the cam shaped reversing member 134 rests in the position illustrated in Figure 4 of the drawings due to gravity with no tension on the spring 154. In this position the reversing lever 164 assumes the position illustrated in full lines in Ififures 2 and 10 of the drawings. When the tever 164 is moved to the dotted line position shown in Figure l() a tension is imposed on the spring 154 which rotates the member 134 on the shaft 82 and causes either of the cam surfaces 138 or 140 thereon to engage one or the other of their respective rollers 142 and 144. For instance, in Figure 11 of the drawings the member 134 has been moved to reversing positionthat is, in the direction of the arrow 167 whereby the cam surface 140 has engaged the roller 144 and raised the holding pawl 122 from engagement with the ratchet wheel 84. The cam member 134 has then continued to move until it has engaged the roller 142 but it cannot lift the lifting pawl 142 from engagement with the ratchet wheel when a load is imposed on the lifting head 52.

Movement of the handle 110 whereby the bars 106 move as indicated by the arrows 168 will allow the ratchet wheel 84 to travel in the direction of the arrow 170 as illustrated in Figure 12. In this case the roller 142 carries the reversing member 134 in the direction of the arrow 172 which moves the cam surface 140 away from the roller 144 and allows the holding pawl spring 124 to draw the holding pawl 122 into engagement with the ratchet wheel 84. Continued movement of the bars 106 in the direction of the arrow 168 as shown in Figure 13 will allow the load on the lifting head to be supported by the holding pawl 122. In this position the spring 154 will pull the member 134 in the direction of the arrow 174 for causing disengagement of the lifting pawl from the teeth of the ratchet wheel. After this operation, movement of the bars 106 in the direction of the arrow 176 will allow the member 134 to rotate in the direction of the arrow 174 so that its cam surface 140 will engage the roller 144 and allow the roller 142 to move away from the cam surface 138 so that the lifting pawl spring 96 will operate to bring the lifting pawl 92 back into engagement with the teeth of the ratchet wheel 84. Continued oscillation of the handle 110 will repeat the cycle of operations outlined in Figures 11 to 14 of the drawings whereby the lifting head 52 may be lowered in a step by step movement. While the lifting head 52 is loaded the strength of the spring 154 is insufficient to overcome the friction between the pawls and the ratchet teeth but when the load is removed, as for instance when in lowering the axle of an automobile the wheel thereon rests on the ground, the load will no longer serve to hold the lifting and holding pawls in engagement with the ratchet wheel 84 and the spring 154 will be free to contract for the purpose of removing the cam member 134 to the position shown in Figure 15 of the drawings. In this positionzboth the cam surfaces 138 and 140 have operated to lift both the lifting and holding pawls from engagement with the ratchet wheel 84 whereby the weight of the lifting arm and lifting head will carry it down by gravity since the ratchet wheel 84 is free to rotate. The foregoing is a very desirable feature so that when the load is removed from the jack it will drop to normally inoperative position without additional oscillating movement being imparted to the operating handle 110. During the operation of my jack from a lower to a raised position it will be noted that the angle of the lifting arms 50 continually changes. For instance, in lowered position the lifting arm slants forwardly and downwardly. At the central portion of the lifting movement, the lifting arm extends substantially horizontal and in raised position the lifting arm slants forwardly and upwardly.

This variation in the inclination of the lifting arm requires a varying amount of power to lift a load, the most power being required during the central portion of the travel of the lifting arm. To counteract this tendency I have arranged my links 88 and 90 to have their upper ends swing at varying angles relative to the bars 114 such varying angles corresponding to the angles assumed by the lifting arm during its raising and lowering movement. In this manner the lifting handle 110 may be oscillated substantially through the same arc while the lifting head is being raised or lowered and the amount of power required thereon will be substantially uniform throughout the lifting movement of the jack. This arrangement is especially desirable when heavy loads approach the limit of capacity of the jack so that excessive energy is not required for the operation of the jack during a portion of its lifting movement.

It will be seen that I have provided a small sized jack having supporting wheels mounted comparatively close to the lifting and operating mechanism of the jack whereby my device may be conveniently moved to position in close places and operated for raising an automobile or truck. The jack itself is steerable by being provided with the caster wheel 20 so that it may be utilized to lift one end of the car and swing it to any desired transverse position which could not be possible by manipulating the car itself without the use of a jack of this character.

The construction of my jack is susceptible to a great deal of variation in the shape and dimensions of the parts and also their arrangement and it is not my purpose to limit myself to the exact construction shown although that construction is a preferable form.

It is my intention therefore to cover by my claims any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a jack having a supporting frame, the combination of a triangular shaped lifting arm, means at one corner thereof for pivoting the lifting arm to the supporting frame, means at anotherl corner for supporting a load engaging head and rotary means at the third corner of the lifting arm, means secured to the supporting frame with which the rotary means cooperates for moving the lifting arm relative to the frame when said rotary means is rotated and operating mechanism for giving said rotary means a step by step movement in either direction, said means comprising a shaft, a ratchet wheel mounted thereon, operating means oscillatably mounted on said supporting frame, and means pivoted on said shaft and operable from said operating means for rotating said ratchet wheel regardless of the position of the lifting arm relative to the supporting frame.

2. In a jack having a supporting frame, the combination of a triangular` sha-ped lifting arm, means at one corner thereof for pivoting the lifting arm to the supporting frame, means at another corner for supporting a load engaging head and rotary means at the third corner of the lifting arm, means secured to the supporting frame with which the rotary means cooperates for moving the lifting arm relative to the frame when said rotary means is rotated and operating mechanism for giving said rotary means a step by step movement in either direction, said means comprising a pawl actuated ratchetwheel, operating means for causing operation of the pawls and cam means pivotally mounted at the aXis of rotation of said ratchet wheel and adapted to successively engage the pawls to cause reverse rotation ofY the ratchet wheel when it is desired to lower a load on the lifting arm.

8. In a jack having a supporting frame, thc combination of a triangular shaped lifting arm, means at one corner thereof for pivoting the lifting arm to the supporting frame, means at another corner for supporting a load engaging head and rotary means at the third corner of the lifting arm, means secured to the supporting frame with which the rotary means cooperates for moving the lifting arm relative to the frame when said rotary means is rotated and operating mechanism for giving said rotary means a step by step movement in either direction, said means comprising a shaft, a ratchet wheel mounted thereon, a step down gearing connection between said ratchet wheel and said pinion, operating means oscillatably mounted on said supporting frame, and

means pivoted on said shaft and operable from said operating means for rotating said ratchet wheel regardless of the position of the lifting arm relative to the supporting frame.

4. In a lifting jack having a supporting frame provided with a pair of wheels at one end and a single caster wheel at the other end, the combination of a triangular shaped lifting arm pivoted to the supporting frame having a load engaging head at one corner thereof and actuating means at another corner and carried by the lifting arm, said actuating means coacting with the supporting frame and adapted upon rotation to move the arm relative to the frame and means oscillatably mounted on the frame and adapted when operated to give the actuating means a step by step rotary movement.

5. In a lifting jack having a supporting frame provided with a pair of wheels at one end and a single caster wheel at the other end, the combination of a triangular shaped lifting arm pivoted to the supporting frame having a load engaging head at one corner thereof and actuating means at another corner coacting with the supporting frame and adapted upon rotation to move the arm relative to the frame and means oscillatably mounted on the frame and adapted when operated to give the actuating means a step by step rotary movement, the connection between said oscillatable means and said rotatable means comprising a ratchet wheel operatively associated with said rotatable means, a lifting pawl engageable therewith and operable by the oscillatable means.

6. In a lifting jack having a supporting frame provided with a pair of wheels at one end and a single caster wheel at the other end, the combination of a triangular shaped lifting arm pivoted to the supporting frame having a load engaging head at one corner thereof and actuating means at another corner coacting with the supporting frame and adapted upon rotation to move the arm relative to the frame and means for causing such rotation comprising a pawl actuated ratchet wheel, operating means for causing operation of the pawls and cam means pivotally mounted at the axis of rotation of said ratchet wheel and adapted to successively engage the pawls to cause reverse rotation of the ratchet wheel when it is desired to lower a load on the lifting arm.

Des Moines, Iowa, October 27, 1927.

LEONARD D. NILSN.

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