US2029022A

US2029022A - Extension head for lifting jacks

Info

Publication number: US2029022A
Application number: US753278A
Authority: US
Inventors: Frank A Graham
Original assignee: American Chain and Cable Co Inc
Current assignee: FKI Industries Inc
Priority date: 1934-11-16
Filing date: 1934-11-16
Publication date: 1936-01-28
Anticipated expiration: 1953-01-28

Description

Jmzs, ma. F AGRAHAM A 1029,@22

EXTENSION HEAD FOR LIFTING JACKS Filed Nov. 16, 1934 Patented Jan. 28, 1936 UN'EE STA-.TES

BA'EENT GFFIQE EXTENSION HEAD Fon LIFTING .mons

Application November 16, 1934, Serial No. 753,278

6 Claims. The present invention relates to lifting jacks and has for an object to provide a novel means for quickly adapting the jack for work at diiferent heights.

The invention is especially (although not exclusively) adapted for use on automobile `iacks. The axles of modern cars are much lower than those of older models and in order to provide a jack which may be adjusted instantly for low N axled or high aXled cars, I have devised a head which may be readily raised or lowered with respect to the normal lifting mechanism of the jack.

A more speciiic object of the invention is to 3;, provide a head comprising a bearing member and a rest plate removably mounted therein, the parts being so constructed and arranged that when the rest plate is applied in one way it will occupy a higher position with respect to the bearing mem- 20 ber than when applied in another way. By this arrangement the rest plate may be normally adapted for use with low aXled cars, but whenever a high axled car is to be jacked up the rest plate is lifted off its bearing and reapplied thereto in such a way as to occupy its higher position. With the above-named objects in View and others which will appear hereinafter I shall now describe a preferred embodiment of my invention and thereafter the novelty and scope of the 30 invention will be pointed out in the claims.

In the accompanying drawing: Figure l is a View in perspective of a jack embodying my improved extension head;

Fig. 2 is a view in section, but on a larger scale, 35 taken on line 2-2 of Fig. 1, and showing the extension head in raised position;

Fig. 3 is a View in section taken on line 3 3 of Fig. 2; and,

Fig. 4 is aview in section, taken on line 4 6 l0 of Fig. 2, but with the head in lowered position. It will be understood that my extension head may be applied to different forms of jacks and that I make no claim to the particular jack illustrated in Fig. 1. The novelty lies in the exten- 45 sion head applied thereto.

The jack I has an extension head comprising a bearing member I I which is pivoted to the lifting armV i2 of the jack and is maintained in vertical position by parallel links I3. The bearing member is formed with a vertical bore I5 adapted to receive the stem I6 oi a rest plate Il. The bore E5 has a pair of diametrically opposed key slots I8 cut therein and extending the full length of the bore. It also has another pair of diametrically opposed key slots i9 cut therein and extending from the top of the bore to 'a point part way down where they terminate in end walls 2Q. The pairs of slots are disposed at 90 degrees to each other. The stem i6 is provided lwith a pair of diametrically opposed keys ZI which are adapt- 5 ed to t into either pair of key slots.

Normally, the rest plate is in its lowermost position which means that the stem has been turned to such position that the keys 2! nt in the keyways I 8. This permits the rest plate to drop until a shoulder 23 on the lower side thereof bears against the upper end of the bearing member II. However, if it be desired to adjust the jack quickly for use with a high axled car, it is merely necessary to lift the head from the position shown in Fig. 4 out of the bearing member and then after turning it through an angle of 90 degrees reinsert the stem in the bearing member with the keys now tting in the keyways I9. The

rest plate will now occupy the position shown in Fig. 2 with the lower ends of the keys resting on the shoulders or walls 2li at the lower ends of the slots I9.

The rest plate is preferably formed as illustrated with a dished upper surface having a marg5 ginal rim. This rim is depressed to form two pairs of diametrically opposed sockets or seats 22 adapted to receive the axle of the car. The axes of these seats are disposed at 90 degrees to each other so that in either angular position of the rest plate there will be a pair of seats in Y proper position to support a car axle transversely with respect to the jack.

Having thus described my invention what I claim as new and on which I desire to secure Letters Patent is as follows:

I claim:

i. A head for a lifting jack comprising, a bearing member, a rest plate member constructed and arranged to be removably supported on the bearing member in either of two positions angularly disposed one to the other, said members being provided with cooperating means to support the rest plate against angular movement and to maintain the rest plate at a materially higher level when applied to the bearing member in one of said positions than when applied to the bearing member in the other.

2. A head for a lifting jack comprising, a bearing member, a rest plate member constructed and arranged to be removably supported by the bearing member in either of two positions disposed at 90 degrees to each other, said members being provided with cooperating means for preventing the rest plate member from turning with 55 and arranged to be removably supported on the bearing member in either of two positions angularly disposed one to the other, one of said members having a bore, the other of said members having a stem adapted to t in the bore, the stem and bore being provided with keys and keywa-ys certain of which are in mutual engagement when the stem is introduced into the bore in one position and others of which are in mutual engagement and cooperate to support the rest plate at a higher level when the stem is introduced into the bore in a different angular position.

4. A head for a lifting jack comprising, a bearing member formed with a vertical bore, and a Yrest plate formed with a stem adapted to fit slidably within said bore, said stem being formed with a pair of diametrically opposed keys and said bore being formed with two pairs of diametrically opposed key slots adapted to receive said keys, one pair of key slots being marially shorter than the other.

5. A head for a lifting jack comprising, a bearing member formed vwith arvertical bore, and a rest plate formed with a stem adapted to fit slidably Within said bore, said stem being formed with a pair of diametrically opposed keys and said bore being formed with two pairs of diametrcally opposed key slots adapted to receive said keys, one pair of key slots being'disposed at 90 degrees to the other and also extending the full length of the bore while said other pair ofV key slots extends from the top, of the bore to a point intermediate the ends Vofthe bore.

6, A head for a lifting jack comprising, a bearing member formed with a vertical bore, and a restplate formed with a stem adapted to fit slid' rably within said bore, said stem being formed with a pair of diametrically opposed keys and said bore being formed with two pairs ofdiametrically opposed key slots adapted to receive said keys, one pair of key slots being disposed at 90 degrees to the other and also extending Vthe full length of the bore while said other pair of key slots extends from the top of the bore to a point intermediate-the ends of the bore, the rest plate having work-receiving depressions on axes at 90 degrees to each other.

FRANK A. GRAHAM.