IP Library › Granted Patent US 12,636,928
Granted Patent B2
US 12,636,928 · App. 18/776,799 · Granted May 26, 2026

Cart stabilization system, rolling cart elements and methods of using same

Inventors: Gerardo Angel Gonzalez Chapa (Austin, TX); Scott Hudson (Pflugerville, TX)
Assignee: Zimmer, Inc.
B60G17/033B60B33/0005B60B33/0042B60B33/0049B60B33/0057B60B33/0068B60B33/0073B60B33/0086B60B33/045B60B33/063B60G17/056B25J5/007B60B2320/10B60B2900/551B60G2202/413B60G2202/416B60G2300/26
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Quick Facts
Patent No.
US 12,636,928
App. No.
18/776,799
Granted
May 26, 2026
Kind
B2
Abstract

A cart stabilization system and rolling cart elements for robotic surgery and other medical instrumentation are disclosed. The cart stabilization system includes a base and lifting caster systems coupled to a bottom portion of the base. Each lifting caster system includes a rolling element, a swivel foot assembly moveably coupled to the rolling element; and a hydraulic mounting base coupled to a portion of the swivel foot assembly. Methods of assembling a lifting caster system and for using a cart stabilization system are also disclosed.

Claims (115)

1 . A cart stabilization system, comprising:

a base; and

a plurality of lifting caster systems coupled to a bottom portion of the base, wherein each of the plurality of lifting caster system comprises:

a rolling element;

a swivel foot assembly moveably coupled to the rolling element; and

a hydraulic mounting base coupled to a portion of the swivel foot assembly; and

wherein the swivel foot assembly comprises:

a foot base;

a spring received within a portion of the foot base;

a lifting shaft movably coupled to the foot base;

a foot mount coupled to a first end of the lifting shaft; and

an O-ring positioned within a channel in a top surface of the foot base.

2 . The cart stabilization system of claim 1 , wherein each of the plurality of lifting caster systems have a passive state and a mobile state, and wherein the plurality of lifting caster systems are energized in the mobile state.

3 . The cart stabilization system of claim 1 , further comprising:

a robot coupled to the base.

4 . The cart stabilization system of claim 1 , wherein the rolling element comprises:

a base member;

two legs coupled to and extending from the base member;

two wheels, each wheel rotatably coupled to the two legs; and

two brakes, each brake moveably coupled to the base member.

5 . The cart stabilization system of claim 4 , wherein the rolling element further comprises:

a cover coupled to and extending from the base member, wherein the cover is positioned to extend over at least a portion of the two legs and the two wheels.

6 . The cart stabilization system of claim 1 , wherein the swivel foot assembly comprises:

a foot base;

a spring received within a portion of the foot base;

a lifting shaft movably coupled to the foot base; and

a foot mount coupled to a first end of the lifting shaft.

7 . The cart stabilization system of claim 6 , wherein the swivel foot assembly further comprises:

a set screw, wherein a second end of the set screw is received within the lifting shaft.

8 . The cart stabilization system of claim 1 , wherein the hydraulic mounting base comprises:

a cap;

a piston, wherein the cap is movably coupled to a shaft of the piston; and

a cylinder body, wherein the piston is movably coupled to the cylinder body by the cap coupling to a portion of an interior surface of the cylinder body.

9 . The cart stabilization system of claim 8 , wherein the hydraulic mounting base further comprises:

a set screw, wherein a first end of the set screw is received within the piston.

10 . The cart stabilization system of claim 1 , further comprising:

a hydraulic system; and

a manifold block comprising:

hydraulic cavity elements;

a pressure sensor; and

pedals.

11 . The cart stabilization system of claim 10 , wherein the hydraulic system comprises:

a pump, and

at least one release valve.

12 . A cart stabilization system comprising:

a base;

a plurality of lifting systems coupled to a bottom portion of the base, each of the plurality of lifting systems comprising:

a rolling element comprising a base member and a wheel;

a foot;

a spring positioned between and engaging both the base member and the foot

wherein the rolling element being movable relative to the foot;

an energizable system including a hydraulic actuator operably connected to the rolling element and to the foot;

wherein energizing the energizable system to reach an energized state causes:

the foot to move in a first direction; and

the base member to move in a second direction opposite the first direction; and

wherein the energizable system is disposable in:

the energized state with each lifting system of the plurality of lifting systems energized to engage the rolling element with a support structure allowing the cart stabilization system to be movable relative to the support structure; and

a deenergized state with each lifting system of the plurality of lifting systems deenergized to engage the foot with the support structure allowing the cart stabilization system to be nonmovable relative to the support structure.

13 . The cart stabilization system of claim 12 , wherein the energizable system is disposable in:

the energized state with the plurality of lifting systems energized to disengage the foot from a support structure.

14 . The cart stabilization system of claim 13 , wherein the energizable system is disposable in:

the deenergized state with the plurality of lifting systems deenergized to disengage the rolling elements from the support structure.

15 . The cart stabilization system of claim 12 , further comprising:

a robot coupled to the base.

16 . The cart stabilization system of claim 15 , wherein the energizable system comprises:

a hydraulic system including the hydraulic actuator;

a pressure sensor; and

a controller operably connected to the hydraulic system and the pressure sensor.

17 . The cart stabilization system of claim 16 , wherein the controller inhibits operation of the robot when the lifting systems are disposed in the energized state.

18 . A method of assembling a lifting caster system, comprising:

obtaining a caster with wheels and brakes coupled to a base member;

positioning a spring between a top surface of the base member and a foot base;

inserting a fastener through a through hole in the base member and into a swivel housing of the foot base;

inserting a second end of a lifting shaft into the swivel housing;

sliding a foot mount over the lifting shaft to position a portion of the lifting shaft within a swivel member in the foot mount;

positioning a cap on a shaft of a piston;

positioning a cylinder body over the piston; and

engaging the cap with an interior groove of the cylinder body.

19 . The method of assembling the lifting caster system of claim 18 , further comprising:

inserting a second end of a set screw into a first end of the lifting shaft; and

inserting a first end of the set screw into a second end of the piston.

20 . The method of assembling the lifting caster system of claim 18 , further comprising:

positioning the spring into a recessed region of an extension member of the foot base.

21 . The method of assembling the lifting caster system of claim 18 , further comprising:

positioning an O-ring in a first channel of a housing of an extension member of the foot base.

22 . The method of assembling the lifting caster system of claim 18 , further comprising:

inserting set screws into screw holes in a side of the foot mount; and

engaging the set screws with key recesses in the lifting shaft coupling the lifting liftin-shaft to the foot mount.

23 . The method of assembling the lifting caster system of claim 18 , further comprising:

coupling the assembled lifting caster systems to a bottom of a base of a cart; and

coupling a robot to a top of the base of the cart.

24 . A lifting caster system comprising:

a rolling element comprising a base member and at least one wheel;

a foot base;

a spring positioned between and engaging both the base member and the foot base;

a hydraulic actuator operably connected to the rolling element and the foot base;

wherein activation of the hydraulic actuator causes:

the foot base to move in a first direction; and

the base member to move in a second direction opposite the first direction; and

wherein deactivation of the hydraulic actuator causes the spring to compress and close a gap between the foot base and the base member.

25 . The lifting caster system of claim 24 , wherein the spring comprises a wave spring configured to maintain the gap when the hydraulic actuator is activated and to compress under weight applied to the foot base when the hydraulic actuator is deactivated.

26 . The lifting caster system of claim 24 , wherein:

when the gap is closed upon deactivation of the hydraulic actuator, the base member directly contacts the foot base; and

weight applied to the base member passes through the base member, through the foot base, and to a support surface via the foot base, providing passive stability without requiring energy input to the hydraulic actuator.

27 . The lifting caster system of claim 24 , wherein:

the at least one wheel comprises two wheels spaced apart from each other;

the foot base comprises a leg member extending from the foot base; and

the leg member and the base member are positioned between the two wheels,

wherein the positioning of the leg member and base member between the two wheels provides obstacle clearance around a circumference of the two wheels.

28 . The lifting caster system of claim 24 , wherein the hydraulic actuator comprises:

a piston having a shaft;

a cap movably coupled to the shaft of the piston;

a cylinder body having an interior groove; and

wherein the piston is movably coupled to the cylinder body by the cap engaging the interior groove,

wherein movement of the piston within the cylinder body causes corresponding movement of the foot base relative to the base member.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 13, 2026
From: MONOGRAM TECHNOLOGIES, LLC
To: ZIMMER, INC.
Reel/Frame 075391/0294 →
CERTIFICATE OF CONVERSION CHANGING COMPANY FROM INC TO LLC Recorded Apr 13, 2026
From: MONOGRAM TECHNOLOGIES INC.
To: MONOGRAM TECHNOLOGIES LLC
Reel/Frame 075384/0004 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 8, 2025
From: GONZALEZ CHAPA, GERARDO ANGEL; HUDSON, SCOTT
To: MONOGRAM TECHNOLOGIES INC.
Reel/Frame 071632/0038 →
Continuity (3)
Continuation PCTUS2023061141 · Jan 24, 2023
Provisional Application 63302414 · Jan 24, 2022
Related Publication 20240367474A1 · Nov 7, 2024
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